Horticulturae

16 pages, 2338 KiB

Open AccessEditor’s ChoiceArticle

Involvement of Organic Acid in the Control Mechanism of ε-Poly-L-lysine (ε-PL) on Blue Mold Caused by Penicillium expansum in Apple Fruits

by Youyuan Li, Wenxiao Jiao, Yamin Du, Min Wang and Maorun Fu

Horticulturae 2022, 8(6), 468; https://doi.org/10.3390/horticulturae8060468 - 25 May 2022

Cited by 2 | Viewed by 2039

Abstract

Blue mold is one of the most serious postharvest diseases in apples caused by Penicillium expansum. The purpose of this study is to determine the effect of ε-poly-L-lysine (ε-PL) on the pathogenicity of P. expansum and explore the potential mechanism from the [...] Read more.

Blue mold is one of the most serious postharvest diseases in apples caused by Penicillium expansum. The purpose of this study is to determine the effect of ε-poly-L-lysine (ε-PL) on the pathogenicity of P. expansum and explore the potential mechanism from the perspective of organic acid. The study investigates the effect of ε-PL treatment on the growth and acid production of P. expansum in vitro and in vivo. When the concentration of ε-PL was 50 mg/L, the growth of P. expansum was inhibited and the decrease in pH value was delayed in the medium. For example, on the third day of culture, P. expansum reduced the pH of the medium from 6.1 to 4.15, and ε-PL inhibited the decrease in the pH value at most 34.4%. When the concentration reached 1000 or 2000 mg/L, the infection of P. expansum in fruits was effectively inhibited. During the growth and infection of P. expansum, gluconic acid is one of the main factors leading to the pH value falling in the local environment. After ε-PL treatment, the accumulation of gluconic acid decreased, the activity of glucose oxidase was suppressed, and then the decline in the local environmental pH slowed down. In addition, after ε-PL treatment, the activities of cell-wall-degrading enzymes, such as cellulase (CL) and polygalacturonase (PG), in the different areas of the P. expansum–apple interaction were also affected by pH change. The results show that ε-PL inhibited the pathogenicity of P. expansum by affecting the accumulation of gluconic acid and slowing the decline in pH in fruit tissues, so as to affect the pathogenicity of P. expansum. This is the first time that the mechanism of ε-PL interfering with the pathogenicity of P. expansum from the perspective of organic acids is clarified. Full article

(This article belongs to the Section Plant Pathology and Disease Management (PPDM))

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11 pages, 896 KiB

Open AccessEditor’s ChoiceArticle

A Sustainable Intercropping System for Organically Produced Lettuce and Green Onion with the Use of Arbuscular Mycorrhizal Inocula

by Eleni Papoui, Filippos Bantis, Nikolaos Kapoulas, Ioannis Ipsilantis and Athanasios Koukounaras

Horticulturae 2022, 8(5), 466; https://doi.org/10.3390/horticulturae8050466 - 21 May 2022

Cited by 4 | Viewed by 2074

Abstract

Arbuscular mycorrhizal fungi (AMF) are efficient for improving crop production and quality in organic farming systems. Our objective was to examine the effects of two AMF inocula, Rhizophagus intraradices and Diversispora spp., against a non-inoculated control on lettuce and green onion grown organically [...] Read more.

Arbuscular mycorrhizal fungi (AMF) are efficient for improving crop production and quality in organic farming systems. Our objective was to examine the effects of two AMF inocula, Rhizophagus intraradices and Diversispora spp., against a non-inoculated control on lettuce and green onion grown organically in an intercropping cropping system. At time of harvest, colonization levels were very low, and not different compared to the control that was colonized by the native mycorrhizal community. The yield of inoculated lettuce and green onion was unchanged, as also observed in the root system architecture analysis parameters. In both crops, color was not affected, limiting the possibility for consumers to reject the product. Nitrate accumulation was well below the limits set by European Commission in all treatments. Sugar, chlorophyll, K, Na and P contents were also quantified, showing no particular variations. In AMF-treated lettuce, important phytochemical characteristics, such as phenol content and ascorbic acid, showed a tendency for reduced values, while antioxidant capacity was significantly reduced by both AMF treatments. The study provides a description about the effect of AMF on two important co-cultivated crops. Research should be continued in order to determine best matches between plant material and AMF inocula that could result in enhanced production and nutritional quality. Full article

(This article belongs to the Section Vegetable Production Systems)

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13 pages, 4091 KiB

Open AccessEditor’s ChoiceArticle

Functional Analysis of Two Terpene Synthase Genes Isolated from the Flowers of Hosta ‘So Sweet’

by Baiqi Cui, Xue Zhao, Guoshuang Chen, Shijie Qin, Yitong Liu, Zhilin Han, Qian Yan, Luwen Han, Sijia Liu, Shuying Liu and Hongzhang Liu

Horticulturae 2022, 8(5), 447; https://doi.org/10.3390/horticulturae8050447 - 17 May 2022

Cited by 2 | Viewed by 2262

Abstract

The Hosta hybrid cultivar ‘So Sweet’, an important ornamental and widely used horticultural plant, is noted for its rich, fragrant white flowers. The main aroma components of Hosta flowers are terpenoids, mainly monoterpenes. Until now, the terpene synthases responsible for terpene production in [...] Read more.

The Hosta hybrid cultivar ‘So Sweet’, an important ornamental and widely used horticultural plant, is noted for its rich, fragrant white flowers. The main aroma components of Hosta flowers are terpenoids, mainly monoterpenes. Until now, the terpene synthases responsible for terpene production in Hosta were not described. In this study, two terpene synthase (TPS) genes (HsTPS1 and HsTPS2) were cloned and characterized to further study their function. Furthermore, the volatile terpenes of Hosta ’So Sweet’ in two flower development stages from two in vitro enzyme tests were analyzed by gas chromatography–mass spectrometry (GC–MS). We analyzed the expression levels of two genes at four different developmental stages using quantitative real-time PCR, while localization was analyzed using Nicotina benthamiana leaves. In vitro, the two proteins were identified to mainly produce linalool and nerol. In addition, the active products of the two recombinant proteins were (E,E)-farnesol and (E,E)-farnesal, respectively, using farnesyl pyrophosphate as a substrate. The high expression of HsTPS1 and HsTPS2 was correlated with the release of components of Hosta flowers. To our knowledge, this is the first time that the terpene synthase genes of Hosta species have been isolated and identified, providing an opportunity to study the terpene metabolic pathways in Hosta species. Full article

(This article belongs to the Section Developmental Physiology, Biochemistry, and Molecular Biology)

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13 pages, 3416 KiB

Open AccessEditor’s ChoiceArticle

Relation between Rind Pigmentation and Internal Quality of Blood Orange ‘Sanguinelli’: Physicochemical and Sensory Studies

by Paula Tarancón, Begoña Cebrián, Paula Fernández-Serrano and Cristina Besada

Horticulturae 2022, 8(5), 448; https://doi.org/10.3390/horticulturae8050448 - 17 May 2022

Cited by 3 | Viewed by 2157

Abstract

This study evaluated the relation between rind colour and the internal physicochemical and sensory qualities of ‘Sanguinelli’ blood oranges, one of the main blood orange cultivars grown in the Mediterranean region. To this end, 400 fruits were harvested in three different orchards and [...] Read more.

This study evaluated the relation between rind colour and the internal physicochemical and sensory qualities of ‘Sanguinelli’ blood oranges, one of the main blood orange cultivars grown in the Mediterranean region. To this end, 400 fruits were harvested in three different orchards and classified according to rind pigmentation intensity (slight, medium, intense, very intense). All fruits were individually evaluated by determining rind and pulp colour, total soluble solids, acidity, maturity index, juice yield, firmness, and size. Moreover, 71 consumers performed a triangle test to evaluate if fruit sensory properties depended on rind pigmentation. Our results revealed (for the first time) that pulp pigmentation and total soluble solid (TSS) content strongly depend on rind colouration. Among the fruit from the same orchard, the redder the pigmented fruit was (externally) the deeper the red pulp, and the higher the TSS became. This pattern was corroborated in the three orchards under study. Other characteristics, such as acidity, juice yield, firmness, and fruit size, did not depend on external pigmentation. Sensory studies showed that the more coloured the fruit, the higher the accumulated sugar content; consumers perceive these fruits as being sweeter than slightly pigmented ones. This information can be very useful for the citrus industry as external colour may become a quality index for blood oranges, as well as for consumers to make purchase decisions. Full article

(This article belongs to the Special Issue Fruits Quality and Sensory Analysis)

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18 pages, 1903 KiB

Open AccessEditor’s ChoiceArticle

Pectin-Based Edible Coating Combined with Chemical Dips Containing Antimicrobials and Antibrowning Agents to Maintain Quality of Fresh-Cut Pears

by Alina Mădălina Pleșoianu and Violeta Nour

Horticulturae 2022, 8(5), 449; https://doi.org/10.3390/horticulturae8050449 - 17 May 2022

Cited by 9 | Viewed by 3417

Abstract

The aim of this study was to assess the effects of pectin coating alone (PE) or combined with chemical dips containing potassium sorbate (PS) or sodium benzoate (SB) as antimicrobials, and N-acetyl cysteine (N-AC) or ascorbic acid (AA) + citric [...] Read more.

The aim of this study was to assess the effects of pectin coating alone (PE) or combined with chemical dips containing potassium sorbate (PS) or sodium benzoate (SB) as antimicrobials, and N-acetyl cysteine (N-AC) or ascorbic acid (AA) + citric acid (CA) as antibrowning agents, on weight loss, color values, browning index, firmness, titratable acidity, soluble solids content, total phenolic content, antioxidant activity and sensory attributes of fresh-cut pears during 15-day storage at 8 °C. Pectin coating delayed weight loss and improved firmness of fresh-cut pears as compared to control samples. Addition of either 1% N-AC or 1% CA + 1% AA in the formulation of the chemical dip protected the phenolic compounds and enhanced the antioxidant activity of fresh-cut pears during storage. PE + 0.2% SB + 1% N-AC and PE + 0.2% PS + 1% N-AC were the most efficient treatments in preserving color and reducing the browning index of fresh-cut pears during 15-day storage at 8 °C and received the highest scores for all sensory attributes throughout 12 days of storage. The results demonstrate the feasibility of PE + 0.2% SB + 1% N-AC and PE + 0.2% PS + 1% N-AC for extending the shelf life of fresh-cut pears. Full article

(This article belongs to the Special Issue Edible Coating and Films as Promising and Sustainable Packaging Materials for Horticultural Products)

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19 pages, 1388 KiB

Open AccessEditor’s ChoiceReview

Application of Elicitors in Grapevine Defense: Impact on Volatile Compounds

by Rafia Salifu, Chunxia Chen, Faisal Eudes Sam and Yumei Jiang

Horticulturae 2022, 8(5), 451; https://doi.org/10.3390/horticulturae8050451 - 17 May 2022

Cited by 6 | Viewed by 2868

Abstract

Elicitors as alternatives to agrochemicals are widely used as a sustainable farming practice. The use of elicitors in viticulture to control disease and improve phenolic compounds is widely recognized in this field. Concurrently, they also affect other secondary metabolites, such as aroma compounds. [...] Read more.

Elicitors as alternatives to agrochemicals are widely used as a sustainable farming practice. The use of elicitors in viticulture to control disease and improve phenolic compounds is widely recognized in this field. Concurrently, they also affect other secondary metabolites, such as aroma compounds. Grape and wine aroma compounds are an important quality factor that reflects nutritional information and influences consumer preference. However, the effects of elicitors on aroma compounds are diverse, as different grape varieties respond differently to treatments. Among the numerous commercialized elicitors, some have proven very effective in improving the quality of grapes and the resulting wines. This review summarizes some of the elicitors commonly used in grapevines for protection against biotic and abiotic stresses and their impact on the quality of volatile compounds. The work is intended to serve as a reference for growers for the sustainable development of high-quality grapes. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress)

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12 pages, 1162 KiB

Open AccessEditor’s ChoiceArticle

Short-Term Pre-Harvest Supplemental Lighting with Different Light Emitting Diodes Improves Greenhouse Lettuce Quality

by Triston Hooks, Ling Sun, Yun Kong, Joseph Masabni and Genhua Niu

Horticulturae 2022, 8(5), 435; https://doi.org/10.3390/horticulturae8050435 - 13 May 2022

Cited by 8 | Viewed by 2580

Abstract

Winter–spring greenhouse vegetable production is limited by low-level natural light, resulting in decreased growth and quality. To investigate whether short-term pre-harvest supplemental lighting (SL) with light emitting diodes (LEDs) can address this issue, a study was conducted in a greenhouse in Dallas, Texas. [...] Read more.

Winter–spring greenhouse vegetable production is limited by low-level natural light, resulting in decreased growth and quality. To investigate whether short-term pre-harvest supplemental lighting (SL) with light emitting diodes (LEDs) can address this issue, a study was conducted in a greenhouse in Dallas, Texas. Red leaf lettuce (Lactuca sativa L. ‘Red Mist’) plants grown in a hydroponic system were treated with daytime or nighttime SL with red (R) and blue (B) LEDs (RB-LED), blue and UVA LEDs (B/UVA-LED), or white LEDs (W-LED) for three days before harvest and compared to those without SL (control). All SL treatments provided a photon flux density of 167 μmol·m⁻²·s⁻¹ for 12 h daily. Compared with the control, SL treatments increased leaf thickness and greenness, antioxidant capacity, and concentrations of phytonutrients such as anthocyanins, carotenoids, and total phenolics; however, shoot fresh biomass and total leaf area were generally not affected by SL. There were no differences in all of the above traits among W-LED, RB-LED and B/UVA-LED. Compared with daytime SL, nighttime SL increased leaf greenness and carotenoid concentration. In summary, all three LEDs with different spectra were effective in improving lettuce quality as short-term pre-harvest SL sources and nighttime SL was more effective than daytime SL; however, plant fresh weight and total leaf area were not affected. Full article

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17 pages, 1880 KiB

Open AccessEditor’s ChoiceArticle

Effects of Fruit Bagging Treatment with Different Types of Bags on the Contents of Phenolics and Monoterpenes in Muscat-Flavored Table Grapes

by Xiao-Yue Wang, Hui-Ling Wang, Guo-Jun Zhang, Ai-Ling Yan, Jian-Cheng Ren, Zhen-Hua Liu, Hai-Ying Xu and Lei Sun

Horticulturae 2022, 8(5), 411; https://doi.org/10.3390/horticulturae8050411 - 6 May 2022

Cited by 6 | Viewed by 3299

Abstract

The effects of fruit bagging treatments with seven different types of bags on the physicochemical characteristics of three table grape cultivars: RuiduZaohong (RDZH), RuiduHongyu (RDHY), and RuiduHongmei (RDHM) were investigated. Headspace-solid-phase micro-extraction combined with gas chromatography mass spectrometry (HS-SPME-GC-MS) was used to determine [...] Read more.

The effects of fruit bagging treatments with seven different types of bags on the physicochemical characteristics of three table grape cultivars: RuiduZaohong (RDZH), RuiduHongyu (RDHY), and RuiduHongmei (RDHM) were investigated. Headspace-solid-phase micro-extraction combined with gas chromatography mass spectrometry (HS-SPME-GC-MS) was used to determine the compositions of monoterpenes in the fruit. The results showed that the total soluble solids in RDZH and RDHY fruits treated with the transparent, mesh, yellow, white, and blue bags were significantly higher than the control. The sugar–acid ratio of RDZH was optimized under the transparent bag and yellow bag treatments, and both significantly increased the sugar-acid ratio of RDHY and RDHM. Additionally, mesh bag, transparent bag, and white bag improved the contents of phenolics to a certain extent. The most abundant volatiles were linalool, geraniol, β-myrcene, β-cis-ocimene, and β-trans-ocimene, of which linalool was the main aroma component. The least squares discriminant analysis results showed that linalool, 4-terpineol, and terpinolen could be used to distinguish the main contribution of different bagging treatments for RDZH. Trans-isogeraniol, α-terpineol, and terpinolen could be used for RDHY. Trans-isogeraniol, β-myrcene, and terpinolen could be used for RDHM. In conclusion, transparent and white bags promoted the accumulation of phenolics and monoterpenes while pink and blue bags showed inhibitory effects. Full article

(This article belongs to the Section Viticulture)

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15 pages, 827 KiB

Open AccessEditor’s ChoiceReview

Biological Control of the Cucumber Downy Mildew Pathogen Pseudoperonospora cubensis

by Zhanbin Sun, Shufan Yu, Yafeng Hu and Yanchen Wen

Horticulturae 2022, 8(5), 410; https://doi.org/10.3390/horticulturae8050410 - 6 May 2022

Cited by 7 | Viewed by 4211

Abstract

Cucumber downy mildew (CDM) is a destructive plant disease caused by the air-borne oomycete pathogen Pseudoperonospora cubensis. CDM causes severe yield reduction of cucumber and significant economic losses. Biocontrol is a promising method to control CDM with the advantage of being beneficial [...] Read more.

Cucumber downy mildew (CDM) is a destructive plant disease caused by the air-borne oomycete pathogen Pseudoperonospora cubensis. CDM causes severe yield reduction of cucumber and significant economic losses. Biocontrol is a promising method to control CDM with the advantage of being beneficial to sustainable agricultural development. However, until now, no reviews of biocontrol of CDM have been reported. The objective of this review is to more comprehensively understand the biocontrol of CDM. In this review, the biological characteristics of P. cubensis are introduced, and strategies for screening biocontrol agents to suppress CDM are recommended. Then the current biocontrol agents, including fungi such as Trichoderma and biocontrol bacteria such as Bacillus, which possess the ability to control CDM, and their control characteristics and ability against CDM are also summarized. The potential mechanisms by which these biocontrol agents prevent CDM are discussed. Finally, several suggestions for future research on the biocontrol of CDM are provided. Full article

(This article belongs to the Section Plant Pathology and Disease Management (PPDM))

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11 pages, 2550 KiB

Open AccessEditor’s ChoiceArticle

RhAGL24 Regulating Auxin-Related Gene RhARF18 Affects Stamen Petaloidy in Rose

by Lin Liu, Yanchao Guo, Zhicheng Wu, Haoran Ren, Yunhe Jiang, Nan Ma, Junping Gao and Xiaoming Sun

Horticulturae 2022, 8(5), 407; https://doi.org/10.3390/horticulturae8050407 - 6 May 2022

Cited by 1 | Viewed by 1924

Abstract

AGAMOUS-LIKE 24 (AGL24) is a key gene regulating floral transition, but its involvement in flower organ identity remains largely unknown. In this study, we found that RhAGL24 is strongly related to petal and stamen development in rose. Its expression increases rapidly at the [...] Read more.

AGAMOUS-LIKE 24 (AGL24) is a key gene regulating floral transition, but its involvement in flower organ identity remains largely unknown. In this study, we found that RhAGL24 is strongly related to petal and stamen development in rose. Its expression increases rapidly at the petal primordium development stage and maintains a high level until the complete differentiation stage. RhAGL24 silencing increases the number of malformed petals and decreases the number of stamens, indicating that this gene affects stamen petaloidy. RhAG (AGAMOUS), a class C gene associated with petal and stamen development, is downregulated in RhAGL24-silenced plants. Moreover, we found that RhAGL24 could directly bind to the promoter region of RhARF18 (AUXIN RESPONSE FACTORS 18), a regulator of RhAG. Our results suggested that RhAGL24-RhARF18 module regulates stamen petaloidy in rose and provide new insights into the function of AGL24 for plants. Full article

(This article belongs to the Section Developmental Physiology, Biochemistry, and Molecular Biology)

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15 pages, 3815 KiB

Open AccessEditor’s ChoiceArticle

OfSPL11 Gene from Osmanthus fragrans Promotes Plant Growth and Oxidative Damage Reduction to Enhance Salt Tolerance in Arabidopsis

by Shoukuo Zhu, Qiu Fang, Yiguang Wang, Shiwei Zhong, Bin Dong and Hongbo Zhao

Horticulturae 2022, 8(5), 412; https://doi.org/10.3390/horticulturae8050412 - 6 May 2022

Cited by 6 | Viewed by 1886

Abstract

Osmanthus fragrans Lour. is a popular and traditional Chinese decorative plant. Salinity is one of the major abiotic stresses affecting the growth and development of O. fragrans. However, the involvement of the SQUAMOSA PROMOTER BINDING PROTEIN-like (SPL) gene in [...] Read more.

Osmanthus fragrans Lour. is a popular and traditional Chinese decorative plant. Salinity is one of the major abiotic stresses affecting the growth and development of O. fragrans. However, the involvement of the SQUAMOSA PROMOTER BINDING PROTEIN-like (SPL) gene in salt stress response is little understood. To elucidate the role of the OfSPL genes in salt stress resistance, we isolated a candidate gene, OfSPL11, from the O. fragrans genotype ‘Yanhong Gui’. OfSPL11 is a transcriptional activator that is located in the nucleus. OfSPL11 is a salt-inducible gene that is highly expressed in young leaves and shoots, according to tissue-specific expression and external treatment. The promoter activity of OfSPL11 is activated by salt treatments in the leaves of tobacco and callus of O. fragrans. The OfSPL11 transgenic lines exhibited better growth and physiological performance; under salt stress, transgenic lines have a faster germination rate, longer roots, and less leaf withering than the wild type (WT). In addition, OfSPL11 overexpression protected the leaves from oxidative damage by suppressing the accumulation of malondialdehyde (MDA) and reactive oxygen species (ROSs) in Arabidopsis. OfSPL11 overexpression can promote the expression of some genes in response to abiotic stresses, including AtCBL1, AtCOR15A, AtCOR6.6, AtRD29A, AtSOS2 and AtSOS3. Yeast one-hybrid assays and transient expression assays showed that OfZAT12 (homologous to Arabidopsis AtRHL41 gene) specifically binds to the OfSPL11 promoter and positively regulates its expression. This study sheds fresh light on the role of OfSPL11 in enhancing salt tolerance in O. fragrans by promoting growth and reducing oxidative damage. Full article

(This article belongs to the Section Biotic and Abiotic Stress)

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15 pages, 303 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Biostimulatory Action of a Plant-Derived Protein Hydrolysate on Morphological Traits, Photosynthetic Parameters, and Mineral Composition of Two Basil Cultivars Grown Hydroponically under Variable Electrical Conductivity

by Michele Ciriello, Luigi Formisano, Christophe El-Nakhel, Giandomenico Corrado and Youssef Rouphael

Horticulturae 2022, 8(5), 409; https://doi.org/10.3390/horticulturae8050409 - 6 May 2022

Cited by 7 | Viewed by 2070

Abstract

Hydroponics is a viable alternative to open field cultivation for year-round vegetable production in urban areas. However, the total dependence on external chemical inputs (fertilizers) makes these systems often less environmentally sustainable. In this perspective, the use of biostimulants could represent a valuable [...] Read more.

Hydroponics is a viable alternative to open field cultivation for year-round vegetable production in urban areas. However, the total dependence on external chemical inputs (fertilizers) makes these systems often less environmentally sustainable. In this perspective, the use of biostimulants could represent a valuable and eco-friendly tool to limit the excessive use of fertilizers without a negative impact on the yield. To this end, our work aimed to evaluate the productive and physiological response of two cultivars of ‘Genovese’ basil (Eleonora and Italiano Classico) for the industrial production of “pesto” grown for 22 days in two nutrient solutions with different electrical conductivity (1 and 2 dS m⁻¹) and the application of two doses of protein hydrolysates (0.15- and 0.30-mL L⁻¹ of Trainer^® in the nutrient solution). The mineral profile was evaluated by ion chromatography coupled with a conductivity detector, while pigments were evaluated by UV-Vis spectrophotometry. Generally, the nutrient solution concentration did not significantly affect the fresh yield of the two cultivars tested. On the contrary, the use of the maximum dose of biostimulant (BT₂ = 0.30 mL L⁻¹ of nutrient solution) increased fresh yield, leaf area, and ACO₂ by 20.7, 27.5, and 17.6%, respectively, compared with the control. Using the lowest dose of biostimulant (BT₁ = 0.15 mL L⁻¹ of the nutrient solution) reduced nitrate by 6.6% compared with the control. The results obtained showed that basil cultivation in a floating raft system combined with biostimulant in the nutrient solution could be an excellent solution to improve productivity, reduce nitrate, and cut fertilizer costs. Full article

(This article belongs to the Special Issue Biostimulants and Plant Elicitors to Mitigate the Effect of Biotic and Abiotic Stress)

14 pages, 1433 KiB

Open AccessEditor’s ChoiceArticle

High-Density Linkage Mapping and Identification of Quantitative Trait Loci Associated with Powdery Mildew Resistance in Flowering Dogwood (Cornus florida)

by Erin Pfarr Moreau, Josh A. Honig and Thomas J. Molnar

Horticulturae 2022, 8(5), 405; https://doi.org/10.3390/horticulturae8050405 - 5 May 2022

Viewed by 1868

Abstract

Flowering dogwood (Cornus florida L.) is a popular, spring-blooming ornamental tree native to the eastern United States. The species is in general very susceptible to powdery mildew caused by Erysiphe pulchra, which disfigures leaves, decreases growth, and negatively affects flowering. Breeding [...] Read more.

Flowering dogwood (Cornus florida L.) is a popular, spring-blooming ornamental tree native to the eastern United States. The species is in general very susceptible to powdery mildew caused by Erysiphe pulchra, which disfigures leaves, decreases growth, and negatively affects flowering. Breeding for resistance has been recognized as an ideal strategy for controlling the disease in C. florida, but efforts have been hindered by the rarity of PM resistance in available germplasm and knowledge of its genetic control. In this study, we mapped quantitative trait loci (QTL) associated with PM resistance/tolerance in two full sibling populations segregating for PM response: Rutgers H4AR15P25 (P25) × Rutgers H4AR15R28 (P28) (n = 195) and Rutgers H4AR15R25 × Rutgers H4AR15P35 (P35) (n = 83). High-density genetic linkage maps were constructed for the mapping populations using double digest restriction-site associated DNA sequencing-derived single nucleotide polymorphisms (SNPs) and simple sequence repeats (SSRs). The P25 × P28 map consisted of 2265 markers, spanning 1520 cM and 11 linkage groups (LGs) with an average marker spacing of 0.69 cM. The P25 × P35 map was constructed with 1788 markers, spanning 1256 cM and 11 LGs, with an average marker spacing of 0.72 cM. The maps had 604 markers in common and exhibited excellent collinearity. Through multiple QTL model mapping, one major QTL (LOD = 11.36 and R² = 58.9%) was identified in P25 × P35. Furthermore, a minor QTL (LOD = 3.30 and R² = 7.8%) was detected in P25 × P28. Due to their proximity onLG3, these QTL may be designating the same locus or tightly linked loci. The negative additive effects of both QTL signify that the PM susceptible male parents were contributing susceptibility alleles to the progeny. This is the first report of QTL associated with PM response on LG3 in C. florida and lays the groundwork for the development of marker-assisted selection for PM resistance in C. florida breeding programs. Full article

(This article belongs to the Topic Plant Breeding, Genetics and Genomics)

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13 pages, 3297 KiB

Open AccessEditor’s ChoiceArticle

Development of a Highly Sensitive Loop-Mediated Isothermal Amplification Incorporated with Flocculation of Carbon Particles for Rapid On-Site Diagnosis of Blood Disease Bacterium Banana

by Mohammad Malek Faizal Azizi, Han Yih Lau, Norliza Abu Bakar, Sohana Romeli, Muhammad Fairuz Mohd Yusof, Rafidah Badrun and Nur Sulastri Jaffar

Horticulturae 2022, 8(5), 406; https://doi.org/10.3390/horticulturae8050406 - 5 May 2022

Viewed by 2111

Abstract

Bananas are one of the most crucial fruit crops worldwide and significantly contribute to food security in developing countries. However, blood disease of bananas caused by Ralstonia syzygii subspecies celebensensis has become a threat to banana production. Rapid and accurate diagnosis of BDB [...] Read more.

Bananas are one of the most crucial fruit crops worldwide and significantly contribute to food security in developing countries. However, blood disease of bananas caused by Ralstonia syzygii subspecies celebensensis has become a threat to banana production. Rapid and accurate diagnosis of BDB for on-site detection is pivotal at an early stage for an effective disease control strategy. This study developed LAMP with specific primers targeting BDB, followed by a flocculation assay for visualising positive amplification in the LAMP assay. The assay was sensitive to picogram amounts of gDNA (0.5 pg). LAMP assay on BDB gDNA showed flocculation, but negative results on Fusarium oxysporus cubense and Ralstonia solanacearum confirming the specificity of the assays. Field testing conducted at MARDI headquarters and Taman Pertanian Universiti discovered that the LAMP-flocculation assays were successful in detecting BDB on symptomatic samples as well as on samples from a healthy plot with no symptom observed at the sampling stage, revealing that this assay can detect BDB at an early infection stage. The validation results showed that the LAMP-flocculation assay was comparable with the PCR technique. This newly developed technique is highly specific and sensitive for the early detection of BDB for the adoption of precautionary control measures. Full article

(This article belongs to the Special Issue Bacterial Diseases in Horticulture: Advances in the Study of Pathogens, Interaction with the Host, Diagnosis and Sustainable Control)

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15 pages, 750 KiB

Open AccessEditor’s ChoiceArticle

The Effect of Low-Growing Rootstocks on the Adaptability and Productivity of Sour Cherry Varieties (Prunus cerasus L.) in Arid Conditions

by Andrey Solonkin, Olga Nikolskaya and Elena Seminchenko

Horticulturae 2022, 8(5), 400; https://doi.org/10.3390/horticulturae8050400 - 2 May 2022

Cited by 3 | Viewed by 1919

Abstract

Sour cherry (Prunus cerasus L.), having a rich composition of biologically active connections and antioxidants, is gaining increasing popularity among agricultural producers. Increasing the production of sour cherry fruits requires the introduction of modern technology, one of the elements of which is [...] Read more.

Sour cherry (Prunus cerasus L.), having a rich composition of biologically active connections and antioxidants, is gaining increasing popularity among agricultural producers. Increasing the production of sour cherry fruits requires the introduction of modern technology, one of the elements of which is low-growing rootstocks. For many cultures, the use of low-growing rootstocks has been widely studied, but there is very little information on their use in cherry plantations. We studied new varieties and rootstocks of cherries in the conditions of the dry steppe zone, where this issue had not been studied before. Sour cherry (Prunus cerasus L.) varieties—Toy, Memory of Zhukova, and Loznovskaya—are the most adapted to the conditions in which the experiments were conducted. Russian breeding forms (Krymsk, Krasnodar region), which were taken as rootstocks, are widely used for sweet cherries (Prunus avium L.), but are practically never used for sour cherries (Prunus cerasus L.). The influence of rootstocks on such parameters as drought resistance, heat resistance, winter hardiness, and productivity was studied in variety–rootstock combinations. The study showed that they had the greatest drought resistance, and accordingly affected the grafted variety with rootstock, in the pedigree of which there are wild species. These rootstocks were of the VSL and RVL series. The study of the productivity of variety–rootstock combinations showed that in the grafted varieties the most rapid entry into the fruiting season and the greatest increase in the yield was facilitated by the rootstock forms of VSL-1 and VSL-2 (K5) which made it possible to obtain a yield of 5.8–8.1 kg/tree, depending on the variety grafted onto them. However, it is necessary to continue the research that has been started in order to fully determine the possible qualitative and quantitative parameters of the studied variety–rootstock combinations and to identify the most promising ones for further introduction into industrial production. This work was carried out within the framework of the topic of the state task of the Scientific Research Center of Agroecology of the Russian Academy of Sciences No. 0713-2019-0009: “Theoretical foundations, creation of new competitive biotypes of agricultural crops with high productivity, quality, sustainability and varietal technologies based on the latest methods and technological solutions in a changing climate, including seed breeding and nursery breeding”. Full article

(This article belongs to the Special Issue New Insights into Rootstock - Scion Interactions in Horticultural Crops)

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12 pages, 317 KiB

Open AccessEditor’s ChoiceReview

UVA and UVB Radiation as Innovative Tools to Biofortify Horticultural Crops with Nutraceuticals

by Daniel A. Jacobo-Velázquez, Melissa Moreira-Rodríguez and Jorge Benavides

Horticulturae 2022, 8(5), 387; https://doi.org/10.3390/horticulturae8050387 - 28 Apr 2022

Cited by 13 | Viewed by 2263

Abstract

The consumption of fruits and vegetables is related to the prevention and treatment of chronic–degenerative diseases due to the presence of secondary metabolites with pharmaceutical activity. Most of these secondary metabolites, also known as nutraceuticals, are present in low concentrations in the plant [...] Read more.

The consumption of fruits and vegetables is related to the prevention and treatment of chronic–degenerative diseases due to the presence of secondary metabolites with pharmaceutical activity. Most of these secondary metabolites, also known as nutraceuticals, are present in low concentrations in the plant tissue. Therefore, to improve the health benefits of horticultural crops, it is necessary to increase their nutraceutical content before reaching consumers. Applying ultraviolet radiation (UVR) to fruits and vegetables has been a simple and effective technology to biofortify plant tissue with secondary metabolites. This review article describes the physiological and molecular basis of stress response in plants. Likewise, current literature on the mechanisms and effects of UVA and UVB radiation on the accumulation of different bioactive phytochemicals are reviewed. The literature shows that UVR is an effective tool to biofortify horticultural crops to enhance their nutraceutical content. Full article

(This article belongs to the Special Issue Chemical Properties, Nutritional Quality, and Bioactive Components of Horticulture Food)

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16 pages, 1426 KiB

Open AccessEditor’s ChoiceArticle

Effect of Elevated Temperature and Excess Light on Photosynthetic Efficiency, Pigments, and Proteins in the Field-Grown Sunflower during Afternoon

by Antonela Markulj Kulundžić, Marija Viljevac Vuletić, Maja Matoša Kočar, Jasenka Antunović Dunić, Ivana Varga, Zvonimir Zdunić, Aleksandra Sudarić, Vera Cesar and Hrvoje Lepeduš

Horticulturae 2022, 8(5), 392; https://doi.org/10.3390/horticulturae8050392 - 28 Apr 2022

Cited by 5 | Viewed by 2663

Abstract

This study examined the photosynthetic responses of two sunflower hybrids to elevated temperatures and excess light intensity in the flowering stage by measuring the chlorophyll a fluorescence (ChlF) under morning and afternoon field conditions to determine the photosynthetic pigment contents and the relative [...] Read more.

This study examined the photosynthetic responses of two sunflower hybrids to elevated temperatures and excess light intensity in the flowering stage by measuring the chlorophyll a fluorescence (ChlF) under morning and afternoon field conditions to determine the photosynthetic pigment contents and the relative accumulation of photosynthetic proteins. The morning environmental conditions were considered optimal, while the afternoon was characterised by elevated temperatures and excess light intensity. The minimum fluorescence intensity (F₀), the electron-flux-reducing end electron acceptors at the photosystem I acceptor side per reaction centre (RE₀/RC), and the D1 protein had significant, high, and positive correlations with the environmental conditions, which indicates that they were the most useful in the sunflower-stress-response research. In hybrid 7, the elevated temperatures and the excess light intensity resulted in the inactivation of the oxygen-evolving complex, which was indicated by the positive L, K, and J steps, the increase in the maximum quantum yield of PSII (TR₀/ABS), the decrease in the electron transport further than the primary acceptor Q_A (ET₀/(TR₀-ET₀)), the reduction in the performance index (PI_ABS), and the higher relative accumulation of the light-harvesting complex of the photosystem (LHCII). Hybrid 4 had smaller changes in the fluorescence curves in phases O–J and J–I, and especially in steps L, K, J, and I, and a higher PI_ABS, which indicates a more efficient excitation energy under the unfavourable conditions. As the tested parameters were sensitive enough to determine the significant differences between the sunflower hybrids in their photosynthetic responses to the elevated temperatures and excess light intensity in the flowering stage, they can be considered useful selection criteria. The development of more adaptable sunflower hybrids encourages sustainable sunflower production under stressful growing conditions. Full article

(This article belongs to the Special Issue Horticultural Plants Facing Stressful Conditions - Ways of Stress Mitigation)

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15 pages, 2024 KiB

Open AccessEditor’s ChoiceArticle

Effect on the Growth and Photosynthetic Characteristics of Anthurium andreanum (‘Pink Champion’, ‘Alabama’) under Hydroponic Culture by Different LED Light Spectra

by Yinglong Song, Wenqian Shang, Dandan Ma, Zheng Wang, Songlin He, Liyun Shi, Yuxiao Shen, Dan He, Erqiang Wang and Xiaohui Wang

Horticulturae 2022, 8(5), 389; https://doi.org/10.3390/horticulturae8050389 - 28 Apr 2022

Cited by 7 | Viewed by 2607

Abstract

Anthurium andreanum was one of the best indoor ornamental plants. Two cultivars of Anthurium andreanum (Pink Champion, Alabama) were used to investigate the effects of light quality on physiological and biochemical indexes. There were six different light quality treatments: Fluorescent Daylight Lamp (CK), [...] Read more.

Anthurium andreanum was one of the best indoor ornamental plants. Two cultivars of Anthurium andreanum (Pink Champion, Alabama) were used to investigate the effects of light quality on physiological and biochemical indexes. There were six different light quality treatments: Fluorescent Daylight Lamp (CK), and RB (100% Blue, 60% R + 40% B, 70% R + 30% B, 80% R + 20% B, 100% Red) provided by light emitting diodes (LED). The results showed that blue light was beneficial to shoot growth and dry matter accumulation, photosynthetic rate, soluble sugar, and POD activities. Red light was beneficial for the synthesis and accumulation of soluble protein, and could promote root growth. ‘Pink Champion’ and ‘Alabama’ obtained the relatively better morphological parameters, chlorophyll contents, photosynthetic parameters, and antioxidant enzyme activities in 7:3 and 6:4 treatments. The antioxidant enzyme (POD, SOD) activities under composite light of red and blue treatments were better than that of monochromatic red, blue light treatments and CK on the whole. Comprehensive evaluation showed that the treatment of 7:3 was a suitable light environment indoors and could be used as the preferred light quality ratio in the production and application of Anthurium andreanum. Full article

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22 pages, 396 KiB

Open AccessEditor’s ChoiceArticle

Assessment of Physicochemical, Macro- and Microelements, Heavy Metals, and Related Human Health Risk from Organically, Conventionally, and Homemade Romanian Wines

by Florin Dumitru Bora, Anamaria Călugăr, Claudiu-Ioan Bunea, Sandor Rozsa and Andrea Bunea

Horticulturae 2022, 8(5), 382; https://doi.org/10.3390/horticulturae8050382 - 27 Apr 2022

Cited by 1 | Viewed by 3077

Abstract

From the consumers’ perspective, organic and homemade products have become more attractive than conventional ones. However, scientific data regarding the characteristics, properties, and composition of these products are scarce. This study assessed the elemental composition of organic, conventional, and homemade Romanian wines. The [...] Read more.

From the consumers’ perspective, organic and homemade products have become more attractive than conventional ones. However, scientific data regarding the characteristics, properties, and composition of these products are scarce. This study assessed the elemental composition of organic, conventional, and homemade Romanian wines. The physicochemical composition, SO₂ (free and total) and total concentration of macroelements, microelements, and heavy metals from nine wine regions containing 165 samples of white (38 organic/70 conventional/57 homemade), 67 red (22/31/14) and 7 rosé (2/2/3) wines were analyzed by inductively coupled plasma mass spectrometry. Dietary intake and target hazard quotient were also evaluated. The phytochemical and elemental compositions of the wine samples varied across regions and wine types. The highest levels of Ca, K, Fe and Al were detected in conventional wines, while homemade wines recorded high concentrations of Na, Mg, V, Ba and Rb. In the case of the rosé wine samples, the levels of trace elements and heavy metals were below the admissible limit. The estimated daily intake of a glass of wine provided less than 0.5% of the tolerable daily intake of the analyzed elements. No health concerns were identified. All wine samples can be safely consumed, regardless of the culture system used for production, and homemade wines are not of a lower quality than organic or conventional wines. Full article

(This article belongs to the Section Viticulture)

18 pages, 1621 KiB

Open AccessEditor’s ChoiceReview

Sanitary Registries and Popular Medicinal Plants Used in Medicines and Herbal Remedies in Mexico (2001–2020): A Review and Potential Perspectives

by Aida Araceli Rodríguez-Hernández, Fernanda Guadalupe Flores-Soria, Omar Patiño-Rodríguez and Abraham Escobedo-Moratilla

Horticulturae 2022, 8(5), 377; https://doi.org/10.3390/horticulturae8050377 - 26 Apr 2022

Cited by 6 | Viewed by 3093

Abstract

Mexico, a megadiverse country, hosts approximately 10–12% of the world’s biodiversity and at least 21,989–23,424 vascular plants, 3350 of which are traditional medicinal flora. The Mexican Regulation categorizes herbal medicinal products into two groups: herbal medicines products and herbal remedies products. To date, [...] Read more.

Mexico, a megadiverse country, hosts approximately 10–12% of the world’s biodiversity and at least 21,989–23,424 vascular plants, 3350 of which are traditional medicinal flora. The Mexican Regulation categorizes herbal medicinal products into two groups: herbal medicines products and herbal remedies products. To date, there is no available information that describes and includes analyzed data about these two types of herbal medicinal products registered in Mexico. The purpose of the study was to analyze national sanitary registries of herbal products from 2001 to 2020 and identify native Mexican plants that are most used in herbal products. Further, the study aims to highlight the impact and relevance of this large number of medicinal plants, which represent a great source of information, genetic resources, bioactive compounds, and potential use in subsequent therapies based on scientific evidence. The future of medicines and herbal remedies is underestimated; thus, the significance of evaluating the great potential in studying plants for medicinal use must be taken into account. Full article

(This article belongs to the Special Issue Botany, Phytochemistry and Pharmacology in Traditional Herbal Medicine)

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12 pages, 1000 KiB

Open AccessEditor’s ChoiceArticle

Cold Treatment Modulates Changes in Primary Metabolites and Flowering of Cut Flower Tulip Hybrids

by Petronia Carillo, Giovanna Marta Fusco, Rosaria Serena Del Gaudio, Stefania De Pascale and Roberta Paradiso

Horticulturae 2022, 8(5), 371; https://doi.org/10.3390/horticulturae8050371 - 24 Apr 2022

Cited by 2 | Viewed by 2113

Abstract

Tulip is one of the most important bulbous genera in the world’s floriculture. It is known that cold exposure of bulbs before planting is required to break the bulb dormancy and to promote the plant’s flowering. Preparation procedures performed by breeders differ in [...] Read more.

Tulip is one of the most important bulbous genera in the world’s floriculture. It is known that cold exposure of bulbs before planting is required to break the bulb dormancy and to promote the plant’s flowering. Preparation procedures performed by breeders differ in the duration and the thermal level, and the choice of the procedure depends on the genotype’s sensitivity to temperature; however, little is known about the metabolic responses underlying the different behaviours of the numerous commercial hybrids. We evaluated the influence of two bulb-preparation procedures, 15–18 weeks at 5 ÷ 9 °C, and 9–14 weeks at 2 ÷ 5 °C, in two hybrids of tulip (Tulipa gesneriana L.), ‘Royal Virgin’ and ‘Ad Rem’, grown hydroponically in a floating system. Tulip plants of the two hybrids responded differently to bulb exposure to low temperatures in terms of early flowering, as this was unaffected by the preparation procedure in ‘Royal Virgin’ (27.1 days from transplanting, on average), while it was earlier after treatment at higher temperatures compared with lower temperatures in ‘Ad Rem’ (24.1 vs. 26.7 days at 5 °C vs. at 9 °C). This different flowering earliness may be related to the diverse metabolic responses enacted by the bulbs for cold acclimation that depended on hybrid x thermal treatment. Plant leaf area and flower stem characteristics were similar in the hybrids and were unaffected by the bulb-preparation procedure. Full article

(This article belongs to the Section Floriculture, Nursery and Landscape, and Turf)

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11 pages, 1978 KiB

Open AccessEditor’s ChoiceArticle

Use of Piriformospora indica to Promote Growth of Strawberry Daughter Plants

by Wei Liu, Min Tan, Pengyan Qu, Chensi Huo, Wenjie Liang, Runlin Li, Yan Jia, Xinping Fan and Chunzhen Cheng

Horticulturae 2022, 8(5), 370; https://doi.org/10.3390/horticulturae8050370 - 23 Apr 2022

Cited by 5 | Viewed by 2341

Abstract

As an endophytic fungus, the growth-promoting effects of Piriformospora indica have been widely confirmed in many of its host plants. In this study, we investigated the influences of P. indica colonization on the growth of the daughter plants of two strawberry cultivars, ‘Benihoppe’ [...] Read more.

As an endophytic fungus, the growth-promoting effects of Piriformospora indica have been widely confirmed in many of its host plants. In this study, we investigated the influences of P. indica colonization on the growth of the daughter plants of two strawberry cultivars, ‘Benihoppe’ and ‘Sweet Charlie.’ The results showed that the fungus colonization significantly promoted the growth of the daughter plants of both of the two strawberry varieties. Its colonization greatly improved almost all of the growth parameters of the ‘Benihoppe’ daughter plants, including the above-ground fresh weight, above-ground dry weight, root fresh weight, root dry weight, plant height, petiole length, leaf area, number of roots and chlorophyll content. However, the fungus colonization showed significant improving effects on only the above-ground fresh weight, root fresh weight and root dry weight of ‘Sweet Charlie.’ Surprisingly, the average root length of ‘Benihoppe’ and ‘Sweet Charlie’ was suppressed by about 14.3% and 24.6%, respectively, by P. indica. Moreover, after P. indica colonization, the leaf nitrate reductase activity and root activity upregulated by 30.12% and 12.74%, and 21.85% and 21.16%, respectively, for the ‘Benihoppe’ and ‘Sweet Charlie’ daughter plants. Our study indicated that P. indica could promote the growth of strawberry daughter plants by improving rooting, strengthening photosynthetic pigments production and nutrient absorption and accelerating biomass accumulation. The fungus shows great potential to be used in the strawberry industry, especially in the breeding of daughter plants. Full article

(This article belongs to the Special Issue Mycorrhizal Roles in Horticultural Plants)

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20 pages, 1471 KiB

Open AccessEditor’s ChoiceReview

Hormonal Signaling in the Progamic Phase of Fertilization in Plants

by Ekaterina V. Zakharova, Marat R. Khaliluev and Lidia V. Kovaleva

Horticulturae 2022, 8(5), 365; https://doi.org/10.3390/horticulturae8050365 - 21 Apr 2022

Cited by 4 | Viewed by 3109

Abstract

Pollen–pistil interaction is a basic process in the reproductive biology of flowering plants and has been the subject of intense fundamental research that has a pronounced practical value. The phytohormones ethylene (ET) and cytokinin (CK) together with other hormones such as auxin, gibberellin [...] Read more.

Pollen–pistil interaction is a basic process in the reproductive biology of flowering plants and has been the subject of intense fundamental research that has a pronounced practical value. The phytohormones ethylene (ET) and cytokinin (CK) together with other hormones such as auxin, gibberellin (GA), jasmonic acid (JA), abscisic acid (ABA), and brassinosteroids (BRs) influence different stages of plant development and growth. Here, we mainly focus on the information about the ET and CK signaling in the progamic phase of fertilization. This signaling occurs during male gametophyte development, including tapetum (TAP) cell death, and pollen tube growth, including synergid programmed cell death (PCD) and self-incompatibility (SI)-induced PCD. ET joins the coordination of successive events in the developing anther, including the TAP development and cell death, anther dehiscence, microspore development, pollen grain maturation, and dehydration. Both ET and CK take part in the regulation of pollen–pistil interaction. ET signaling accompanies adhesion, hydration, and germination of pollen grains in the stigma and growth of pollen tubes in style tissues. Thus, ET production may be implicated in the pollination signaling between organs accumulated in the stigma and transmitted to the style and ovary to ensure successful pollination. Some data suggest that ET and CK signaling are involved in S-RNase-based SI. Full article

(This article belongs to the Special Issue Physiology and Molecular Biology of Flowering, Fruit Setting, Fruit Quality)

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16 pages, 3401 KiB

Open AccessEditor’s ChoiceArticle

Genome-Wide Analyses of Tea Plant Stress-Associated Proteins (SAPs) Reveal the Role of CsSAP12 in Increased Drought Tolerance in Transgenic Tomatoes

by Shu-Chen Fan, Chun Li, Shao-Hua Li, Jie Tang, Hong-Di Shi, Tian-Ming Yang, Ming-Zhi Liang and Dan-Dan Liu

Horticulturae 2022, 8(5), 363; https://doi.org/10.3390/horticulturae8050363 - 21 Apr 2022

Cited by 2 | Viewed by 2004

Abstract

Plant stress-associated proteins (SAPs) contain A20/AN1 zinc finger domains and are involved in plant response to abiotic stresses. In this study, we aimed to explore the biological function of tea plant CsSAPs. A total of 14 CsSAP genes were identified in the tea [...] Read more.

Plant stress-associated proteins (SAPs) contain A20/AN1 zinc finger domains and are involved in plant response to abiotic stresses. In this study, we aimed to explore the biological function of tea plant CsSAPs. A total of 14 CsSAP genes were identified in the tea plant genome using a reference genome database (Camellia sinensis var. sinensis). The CsSAPs were divided into the following two groups: Group I, containing one AN1 domain and/or one A20 domain; and Group II, containing two AN1 domains and/or two C2H2 domains. The sequence alignments and conserved domains analysis indicated that the CsSAPs were highly structurally conserved in terms of amino acid sequence and protein structure. The CsSAPs showed different transcript levels in spatio-temporal expression and in response to cold and drought stress in tea plants. Furthermore, the expression of CsSAP12 was considerably upregulated under drought stress. The overexpression of CsSAP12 in transgenic tomatoes showed increased tolerance to drought stress compared with the wild type. Altogether, the results showed that CsSAP12 might be involved in drought stress. Thus, CsSAP12 might be a target gene in genetic engineering to improve drought tolerance in tea plants. Full article

(This article belongs to the Topic Physiological and Molecular Characterization of Crop Tolerance to Abiotic Stresses)

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15 pages, 2127 KiB

Open AccessEditor’s ChoiceArticle

Irrigation Levels and Fertilization Rates as Pre-Harvest Factors Affecting the Growth and Quality of Hippeastrum

by Chaiartid Inkham, Kanokwan Panjama and Soraya Ruamrungsri

Horticulturae 2022, 8(4), 345; https://doi.org/10.3390/horticulturae8040345 - 18 Apr 2022

Cited by 1 | Viewed by 2308

Abstract

Growing Hippeastrum in an open field or a greenhouse requires precision irrigation and fertilizer to promote plant growth and development. Therefore, this research aimed to study the effect of irrigation level combined with fertilization rate on the growth and development of Hippeastrum. [...] Read more.

Growing Hippeastrum in an open field or a greenhouse requires precision irrigation and fertilizer to promote plant growth and development. Therefore, this research aimed to study the effect of irrigation level combined with fertilization rate on the growth and development of Hippeastrum. Two experiments were carried out to determine the influence of irrigation and fertilizer on the growth, flowering, and bulb quality of Hippeastrum. In the first experiment, bulbs of Hippeastrum ‘Red Lion’ with circumferences of 25 cm were grown in plastic plots using mixed soil as growing media under a 50% shading net. Plants were irrigated daily until drainage and water contained in macropores by gravity action (Field capacity: FC) for 90 days after planting (DAP) and supplied with three different 15N-15P₂O₅-15K₂O fertilization rates, i.e., 0, 2.5, and 5 g per pot. Plant growth and water use efficiency were measured at 45, 60, and 90 DAP. The results showed that plants supplied with 0 g of fertilizer had the lowest plant height and number of leaves per plant at 90 DAP, whereas there was no significant effect of fertilizer rate treatments on flower quality. The water use efficiency, evapotranspiration rate (ET), crop evapotranspiration under standard condition (ETc), crop coefficient (Kc), photosynthetic rate, and stomatal conductance were decreased when plants were supplied with fertilizer at a rate of 0 g per pot at 90 DAP. In the second experiment, plants were irrigated with four levels, i.e., 100, 75, 50, and 25% ETc combined with three fertilization rates, i.e., 0, 2.5, and 5 g per pot. At 180 DAP, the results showed that water deficit treatment (50 and 25% ETc) decreased plant growth and bulb quality. Irrigation with 100% ETc combined with 2.5 or 5 g per pot and irrigation with 75% ETc combined with 5 g per pot were the optimum levels to promote plant growth and bulb quality in Hippeastrum. Full article

(This article belongs to the Special Issue Factors Affecting Export Flower Quality and Strategies for Prolonging Flowers Vase Life)

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7 pages, 922 KiB

Open AccessEditor’s ChoiceArticle

Growth Characteristics of Lettuce Relative to Generation Position of Air Anions in a Closed-Type Plant Factory

by Jin-Ho Won, Byeong-Hyo Cho, Yong-Hyeon Kim and Jung-Hyun Lee

Horticulturae 2022, 8(4), 346; https://doi.org/10.3390/horticulturae8040346 - 18 Apr 2022

Cited by 1 | Viewed by 2058

Abstract

(1) Background: We studied how the generation position of air anions in a closed-type plant factory affects the growth characteristics of lettuce and identified the optimal position. (2) Methods: We used LEDs (red/green/blue = 8:1:1) as a light source and set the temperature [...] Read more.

(1) Background: We studied how the generation position of air anions in a closed-type plant factory affects the growth characteristics of lettuce and identified the optimal position. (2) Methods: We used LEDs (red/green/blue = 8:1:1) as a light source and set the temperature and RH of the plant factory to 20 ± 2 ℃ and 50% ± 5%, respectively. We grew lettuce under three air anion conditions—sideward, upward, and downward—and compared the growth characteristics to those of a control grown without air anions. We measured the growth characteristics of the lettuce at 3 and 4 weeks after sowing, and the measurement items were shoot fresh weight (FW) and dry weight (DW); leaf area (LA), length (LL), and width (LW); SPAD; antioxidant capacity; and total phenol content. (3) Results: At 4 weeks, FW in the downward treatment condition was 25.3% higher than in the control, and DW showed a similar difference. LA was about 1943.94 cm²/plant in the downward treatment condition, which was about 15.5% higher than in the control. (4) Conclusions: We conclude that air anion generation has a positive effect on lettuce growth, and the optimal generation position for air anions is downward. Full article

(This article belongs to the Section Vegetable Production Systems)

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15 pages, 1763 KiB

Open AccessEditor’s ChoiceArticle

The True Identity of the “Second Pollen Morphology” of Camellia oleifera—Stomium Cells

by Yang Hu and Chao Gao

Horticulturae 2022, 8(4), 347; https://doi.org/10.3390/horticulturae8040347 - 18 Apr 2022

Cited by 1 | Viewed by 2292

Abstract

Previous studies on Camellia oleifera pollen morphology have indicated dual morphologies, defined as “dimorphism”. However, they were limited to morphological studies at the end of final development and did not elucidate the origin, structure, and function of the second pollen morphology (striate pollen). [...] Read more.

Previous studies on Camellia oleifera pollen morphology have indicated dual morphologies, defined as “dimorphism”. However, they were limited to morphological studies at the end of final development and did not elucidate the origin, structure, and function of the second pollen morphology (striate pollen). In this study, the differences between the two “pollen” types were compared by paraffin sections, scanning electron microscopy (SEM), fluorescence microscopy, and in vitro germination. The results clearly showed that the second pollen type was formed by stomium cells of the anther, which is responsible for anther dehiscence. The nucleus and vesicles of the stomium cell were specifically distributed during anther development, which may be related to the formation of the septum, pollen dispersal activity, and the increase in stomium cell count; at the microscopic level, the stomium cell mainly consisted of the cell wall, large vesicles, and nucleus. The large vesicles facilitate the rapid dehydration of stomium cells under suitable conditions for anther dehiscence. Furthermore, studies on other species of the genus Camellia have suggested that the second type of pollen morphology is pseudopollen, which is capable of partaking in deceptive pollination. The present study refuted this theory and suggested that the pseudopollen are stomium cells, whose structure relates to their function. These results provide the basis for further research on C. oleifera pollen physiology toward the improvement of pollination rates with agricultural practices or breeding interventions. Full article

(This article belongs to the Section Propagation and Seeds)

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19 pages, 2538 KiB

Open AccessEditor’s ChoiceArticle

Combining Cultural Tactics and Insecticides for the Management of the Sweetpotato Whitefly, Bemisia tabaci MEAM1, and Viruses in Yellow Squash

by Angela Gabrielle LaTora, Clarence Bagayao Codod, Saioa Legarrea, Bhabesh Dutta, Robert C. Kemerait, Jr., Scott Adkins, William Turechek, Timothy Coolong, Andre Luiz Biscaia Ribeiro da Silva and Rajagopalbabu Srinivasan

Horticulturae 2022, 8(4), 341; https://doi.org/10.3390/horticulturae8040341 - 17 Apr 2022

Cited by 8 | Viewed by 3132

Abstract

The sweetpotato whitefly, Bemisia tabaci MEAM1 Gennadius (Hemiptera: Aleyrodidae), and the complex of viruses it transmits are major limiting factors to squash production in the southeastern United States. At this time, insecticides are extensively relied upon for the management of whiteflies and, indirectly, [...] Read more.

The sweetpotato whitefly, Bemisia tabaci MEAM1 Gennadius (Hemiptera: Aleyrodidae), and the complex of viruses it transmits are major limiting factors to squash production in the southeastern United States. At this time, insecticides are extensively relied upon for the management of whiteflies and, indirectly, whitefly-transmitted viruses. The development of a multi-faceted, integrated pest management (IPM) program is needed to increase the sustainability and profitability of squash production. Experiments in 2018 and 2019 evaluated the effects of insect exclusion netting (IEN) in combination with selected pesticides on whitefly population dynamics and virus incidence in greenhouse-grown squash seedlings. Field experiments from 2018 to 2021 evaluated the effects of mulch type (UV-reflective mulch, live mulch, and white plastic mulch), row covers, and insecticides on whitefly population dynamics, silver leaf disorder (SSL) intensity, virus symptom severity, and marketable yield. IEN significantly reduced whiteflies and virus incidence on squash seedlings in the greenhouse study. In the field mulch study, lower whitefly abundance and SSL intensity, as well as reduced virus symptom severity, were observed in plots with reflective mulch compared with white plastic or live mulch. In the insecticide/row cover study, whitefly abundance, SSL intensity, and virus symptom severity were lowest in the row cover and cyantraniliprole- and flupyradifurone-treated plots. Field plots with row covers and those with UV-reflective mulch consistently produced the greatest marketable yields. These findings demonstrate that growers can reduce whitefly and virus pressure and preserve yields in squash production in the southeastern United States by combining cultural and chemical tactics, including row covers, UV-reflective mulch, and select insecticides. Full article

(This article belongs to the Special Issue Implementation of IPM Measures in Vegetable Cropping Systems)

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14 pages, 14388 KiB

Open AccessEditor’s ChoiceArticle

Impact of Pseudomonas sp. SVB-B33 on Stress- and Cell Wall-Related Genes in Roots and Leaves of Hemp under Salinity

by Roberto Berni, Jean-Francois Hausman, Silas Villas-Boas and Gea Guerriero

Horticulturae 2022, 8(4), 336; https://doi.org/10.3390/horticulturae8040336 - 15 Apr 2022

Cited by 5 | Viewed by 2064

Abstract

Salinity is a type of abiotic stress that negatively affects plant growth and development. Textile hemp (Cannabis sativa L.) is an important multi-purpose crop that shows sensitivity to salt stress in a genotype- and developmental stage-dependent manner. The root and shoot biomasses [...] Read more.

Salinity is a type of abiotic stress that negatively affects plant growth and development. Textile hemp (Cannabis sativa L.) is an important multi-purpose crop that shows sensitivity to salt stress in a genotype- and developmental stage-dependent manner. The root and shoot biomasses decrease in the presence of NaCl during vegetative growth and several stress-responsive genes are activated. Finding environmentally friendly ways to increase plant health and resilience to exogenous stresses is important for a sustainable agriculture. In this context, the use of beneficial bacteria, collectively referred to as plant growth-promoting bacteria (PGPB), is becoming an attractive and emergent agricultural strategy. In this study, data are provided on the effects of a Pseudomonas isolate (Pseudomonas sp. SVB-B33) phylogenetically closely related to P. psychrotolerans applied via roots to salt-stressed hemp. The application of both living and dead bacteria impacts the fresh weight of the root biomass, as well as the expression of several stress-related genes in roots and leaves. These results pave the way to future investigations on the use of Pseudomonas sp. SVB-B33 in combination with silica to mitigate stress symptoms and increase the resilience to other forms of exogenous stresses in textile hemp. Full article

(This article belongs to the Special Issue Cell Wall Composition and Extract)

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16 pages, 30508 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Woody Canker and Shoot Blight Caused by Botryosphaeriaceae and Diaporthaceae on Mango and Litchi in Italy

by Dalia Aiello, Vladimiro Guarnaccia, Mariangela Benedetta Costanzo, Giuseppa Rosaria Leonardi, Filomena Epifani, Giancarlo Perrone and Giancarlo Polizzi

Horticulturae 2022, 8(4), 330; https://doi.org/10.3390/horticulturae8040330 - 14 Apr 2022

Cited by 11 | Viewed by 2809

Abstract

In recent years, the cultivation of tropical fruit crops has increased in the Mediterranean basin, especially in southern Italy. In surveys conducted from 2014 to 2019 woody canker and shoot blight were observed on mango plants (cvs. Kent, Keitt, Sensation, Osteen, and Kensington [...] Read more.

In recent years, the cultivation of tropical fruit crops has increased in the Mediterranean basin, especially in southern Italy. In surveys conducted from 2014 to 2019 woody canker and shoot blight were observed on mango plants (cvs. Kent, Keitt, Sensation, Osteen, and Kensington Pride) and litchi plants (cvs. Way Chee and Kwai Mai Pink) cultivated in Sicily. Botryosphaeriaceae and Diaporthaceae were consistently isolated from symptomatic samples. Morphological characterization and multi-locus phylogenies using three genomic loci (a portion of translation elongation factor 1-α gene, a portion of the β-tubulin gene, and an internal transcribed spacer) identified these fungi as Neofusicoccum parvum, Lasiodiplodia theobromae, Botryosphaeria dothidea, Diaporthe foeniculina, and Diaporthe baccae on mango and Diaporthe foeniculina and Diaporthe rudis on litchi. Pathogenicity tests on healthy mango (cv. Kensington Pride) and litchi (cv. Way Chee) plants demonstrated the pathogenicity of the isolates used in the study, and Koch’s postulates were fulfilled for all pathogens. To our knowledge, this is the first report of L. theobromae, B. dothidea, and Diaporthe species on mango in Italy and the first report worldwide of woody canker and shoot blight caused by D. foeniculina and D. rudis on litchi plants. Full article

(This article belongs to the Special Issue Pathogens and Disease Control of Fruit Trees)

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14 pages, 520 KiB

Open AccessEditor’s ChoiceReview

How to Measure Organic Fruit Consumer Behavior: A Systematic Review

by Alejandro Vega-Muñoz, Miseldra Gil-Marín, Nicolás Contreras-Barraza, Guido Salazar-Sepúlveda and Analia Verónica Losada

Horticulturae 2022, 8(4), 318; https://doi.org/10.3390/horticulturae8040318 - 9 Apr 2022

Cited by 3 | Viewed by 2946

Abstract

This review article seeks to systematically identify appropriate ways to measure the consumption behavior of organic fruits. The systematic review of the literature was performed according to the criteria of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the [...] Read more.

This review article seeks to systematically identify appropriate ways to measure the consumption behavior of organic fruits. The systematic review of the literature was performed according to the criteria of the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the eligibility criteria were declared through the PICOS (population, interventions, comparators, outcomes, and study) tool based on 277 article records scientiometrically identified in both the Journal Citation Report databases from Web of Science. The literature review stages determined a reduced set of articles that presented valid and reliable measurement scales that covered determinant constructs in organic fruit consumer behavior (OFCB). The measurement scale with the best results reported within the screened articles covered the constructs related to health, fear, environment, effort, and economy, allowing it to serve as a reference instrument in further studies on food consumer behavior. Full article

(This article belongs to the Collection Horticultural Economics, Policy, Business Management and Marketing: The Challenge of Sustainability)

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15 pages, 2388 KiB

Open AccessEditor’s ChoiceArticle

Genetic Analysis of the Grapevine GATA Gene Family and Their Expression Profiles in Response to Hormone and Downy Mildew Infection

by Tingting Chen, Jing Peng, Meijie Li, Mengru Dou, Yan Lei, Yuejing Wang and Yan Xu

Horticulturae 2022, 8(4), 303; https://doi.org/10.3390/horticulturae8040303 - 3 Apr 2022

Cited by 2 | Viewed by 1990

Abstract

Grapevine (Vitis. vinifera L.) is one of the most economically important fruit crops throughout the world. However, grape production is increasingly impacted by numerous diseases, including downy mildew, caused by the oomycete Plasmopara viticola. In grapevine and other plants, members of [...] Read more.

Grapevine (Vitis. vinifera L.) is one of the most economically important fruit crops throughout the world. However, grape production is increasingly impacted by numerous diseases, including downy mildew, caused by the oomycete Plasmopara viticola. In grapevine and other plants, members of the GATA family of transcription factors play key roles in light and phytohormone signaling. However, little is known about their potential roles in biotic defense responses. As a first step, we identified 27 GATA transcription factors in grapevine and defined their transcriptional responses to three biotic stress-related phytohormones (SA, MeJA, and BR) in callus cells, and challenge with P. viticola in a downy mildew-sensitive cultivar, V. vinifera ‘Pinot noir’, and a resistant cultivar, V. piasezkii ‘Liuba-8′. Many of the VvGATA genes had higher expression at 0.5 h after hormones treatments. Moreover, a group of VvGATAs was dramatically induced in ‘Liuba-8′ at 24 post infection by P. viticola. However, the same genes were significantly repressed and showed low expression levels in ‘Pinot noir’. Additionally, VvGATA27 was located in the nucleus and had transcriptional activity. Taken together, the study identified the GATA full gene families in grapes on phylogenetic analysis and protein structure. Moreover, this study provided a basis for discussing the roles of VvGATAs in response to hormones and P. viticola infection. Our results provided evidence for the selection of candidate genes against downy mildew and lay the foundation for further investigation of VvGATA transcription factors. Full article

(This article belongs to the Special Issue Stress Biology of Horticultural Plants)

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12 pages, 2640 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Application of an Alternative Nutrient Replenishment Method to Electrical Conductivity-Based Closed-Loop Soilless Cultures of Sweet Peppers

by Tae-In Ahn and Jung-Eek Son

Horticulturae 2022, 8(4), 295; https://doi.org/10.3390/horticulturae8040295 - 30 Mar 2022

Cited by 4 | Viewed by 1945

Abstract

The nutrient replenishment method primarily impacts the nutrient variations in a closed-loop soilless culture system. However, there is still a lack of systematic approaches for the effective way of nutrient replenishment. Our previous study theoretically derived and experimentally validated an alternative nutrient replenishment [...] Read more.

The nutrient replenishment method primarily impacts the nutrient variations in a closed-loop soilless culture system. However, there is still a lack of systematic approaches for the effective way of nutrient replenishment. Our previous study theoretically derived and experimentally validated an alternative nutrient replenishment method expecting synchronized total fertilizer supply to total nutrient absorption by crops and lower concentration fluctuations than conventional methods. However, no individual nutrient management has been performed. The objective of this study was to apply individual nutrient management to the alternative nutrient replenishment technique under experimental- and commercial-scale electrical conductivity (EC)-based closed-loop soilless cultures. Automated nutrient solution mixing modules and sweet peppers grown on rockwool slabs were used. Nutrient concentrations and crop productivity were compared between the closed-loop system using the alternative nutrient replenishment and the conventional open-loop systems. During early treatment, rapid decreases in K⁺ and H₂PO₄⁻ were observed in the closed-loop system. However, after the stock solution nutrient adjustment, the decreasing trend was stabilized and returned close to initial concentrations. No significant differences in sugar content, incidence of blossom-end rot, and productivity of sweet peppers were observed between the closed- and open-loop soilless cultures. We confirmed that the nutrient variation stabilizing effect of the alternative nutrient replenishment method was valid under nutrient adjustment conditions and had comparable nutrient management performance with the open-loop system. Full article

(This article belongs to the Special Issue Hydroponics in Vegetable Production)

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22 pages, 489 KiB

Open AccessFeature PaperEditor’s ChoiceArticle

Willingness-to-Pay for Produce: A Meta-Regression Analysis Comparing the Stated Preferences of Producers and Consumers

by Alice Kilduff and Daniel Tregeagle

Horticulturae 2022, 8(4), 290; https://doi.org/10.3390/horticulturae8040290 - 29 Mar 2022

Cited by 1 | Viewed by 2438

Abstract

Willingness-to-pay (WTP) estimates help agribusinesses estimate whether a new product is likely to be profitable. For produce, new products, such as new fruit varieties, need to be adopted by producers before they can be sold to consumers. The study of ex ante fruit [...] Read more.

Willingness-to-pay (WTP) estimates help agribusinesses estimate whether a new product is likely to be profitable. For produce, new products, such as new fruit varieties, need to be adopted by producers before they can be sold to consumers. The study of ex ante fruit and vegetable producer preferences is relatively new. This study uses meta-regression analysis to compare the estimated WTP premium between U.S. producers and consumers to determine whether they differ. After controlling for differences in study methods, product attributes, and potential publication bias, the producer WTP was between 14.16 and 27.73 percentage points higher. Subject to several caveats and limitations, this suggests that consumer WTP can be a sufficient metric for the profitability of new produce products. Full article

(This article belongs to the Special Issue Economics and Management of Fruit and Vegetable Production)

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16 pages, 3594 KiB

Open AccessEditor’s ChoiceArticle

Weather Conditions Influence on Lavandin Essential Oil and Hydrolate Quality

by Milica Aćimović, Biljana Lončar, Jovana Stanković Jeremić, Mirjana Cvetković, Lato Pezo, Milada Pezo, Marina Todosijević and Vele Tešević

Horticulturae 2022, 8(4), 281; https://doi.org/10.3390/horticulturae8040281 - 27 Mar 2022

Cited by 16 | Viewed by 2452

Abstract

Lavandula sp. essential oil and hydrolate are commercially valuable in various industry branches with the potential for wide-ranging applications. This study aimed to evaluate the quality of these products obtained from L. x intermedia cv. ‘Budrovka’ for the first time cultivated on Fruška [...] Read more.

Lavandula sp. essential oil and hydrolate are commercially valuable in various industry branches with the potential for wide-ranging applications. This study aimed to evaluate the quality of these products obtained from L. x intermedia cv. ‘Budrovka’ for the first time cultivated on Fruška Gora Mt. (Serbia) during three successive seasons (2019, 2020, and 2021). Essential oil extraction was obtained by steam distillation, and the composition and influence of weather conditions were also assessed, using flowering tops. The obtained essential oils and hydrolates were analysed by gas chromatography with a flame ionization detector (GC-FID) and gas chromatography coupled to mass spectrometry (GC-MS). A linear regression model was developed to predict L. x intermedia cv. ‘Budrovka’ essential oil volatile compound content and hydrolate composition during three years, according to temperature and precipitation data, and the appropriate regression coefficients were calculated, while the correlation analysis was employed to analyse the correlations in hydrolate and essential oil compounds. To completely describe the structure of the research data that would present a better insight into the similarities and differences among the diverse L. x intermedia cv. ‘Budrovka’ samples, the PCA was used. The most dominant in L. intermedia cv. ‘Budrovka’ essential oil and hydrolate were oxygenated monoterpenes: linalool, 1,8-cineole, borneol, linalyl acetate, and terpinene-4-ol. It is established that the temperature was positively correlated with all essential oil and hydrolate compounds. The precipitations were positively correlated with the main compounds (linalool, 1,8-cineole, and borneol), while the other compounds’ content negatively correlated to precipitation. The results indicated that Fruška Gora Mt. has suitable agro-ecological requirements for cultivating Lavandula sp. and providing satisfactory essential oil and hydrolate. Full article

(This article belongs to the Special Issue Medicinal, Aromatic, Spice Plants: Biodiversity, Phytochemistry, Bioactivity and Their Processing Innovation)

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11 pages, 253 KiB

Open AccessEditor’s ChoiceArticle

Producing Cherry Tomatoes in Urban Agriculture

by Matthew L. Richardson and Caitlin G. Arlotta

Horticulturae 2022, 8(4), 274; https://doi.org/10.3390/horticulturae8040274 - 22 Mar 2022

Cited by 6 | Viewed by 3305

Abstract

Agriculture in urban and urbanizing areas will be increasingly critical to enhancing food security and food sovereignty, creating income, strengthening social interactions, and improving health outcomes in cities. We used three roofs, a hydroponic system, an aquaponic system, and field rows in an [...] Read more.

Agriculture in urban and urbanizing areas will be increasingly critical to enhancing food security and food sovereignty, creating income, strengthening social interactions, and improving health outcomes in cities. We used three roofs, a hydroponic system, an aquaponic system, and field rows in an urban environment to grow six dwarf tomato cultivars: ‘Micro Tom’, ‘Red Robin’, ‘Sweet ‘n’ Neat’, ‘Terenzo’, ‘Tiny Tim’, and ‘Tumbler.’ We measured the marketable yield and non-marketable yield, mass of non-marketable tomatoes exhibiting defects, and the content of 12 mineral nutrients in fruits. We found the productivity often varied among cultivars within a cropping system. ‘Terenzo’ and ‘Tumbler’ were always some of the most productive cultivars, whereas ‘Micro Tom’ was normally among the least productive cultivars. The production from ‘Red Robin’, ‘Tiny Tim’, and ‘Sweat ‘n’ Neat’ was more variable, sometimes producing high, moderate, or low mass. The mineral content was especially variable across the cultivars and we did not identify cultivars that were consistently high or low in mineral content across systems, indicating that the mineral content was highly influenced by a genotype x environment interaction. The amount of 5 minerals differed across cultivars in aquaponics, 9 differed in hydroponics, and 6–12 differed in the roof systems. A high-yielding cultivar should be selected first and production methods can then be modified to maximize the nutrient content. Full article

(This article belongs to the Special Issue Urban Horticulture - New Trends and Technologies)

15 pages, 3127 KiB

Open AccessEditor’s ChoiceArticle

Characterization of Young Shoot Population, Yield, and Nitrogen Demands of Tea (Camellia sinensis L.) Harvested under Different Standards

by Lizhi Long, Yuanzhi Shi, Lifeng Ma and Jianyun Ruan

Horticulturae 2022, 8(4), 275; https://doi.org/10.3390/horticulturae8040275 - 22 Mar 2022

Cited by 5 | Viewed by 2255

Abstract

The quality of green tea is greatly influenced by the harvest standards for young shoots. The present field experiment was conducted to characterize the young shoot populations, yields, and nitrogen (N) demands of tea plants subjected to four different harvest standards, i.e., buds [...] Read more.

The quality of green tea is greatly influenced by the harvest standards for young shoots. The present field experiment was conducted to characterize the young shoot populations, yields, and nitrogen (N) demands of tea plants subjected to four different harvest standards, i.e., buds with one, two, or three young expanding leaves (referred to as B1L, B2L, and B3L, respectively) and a combination of B1L and B3L (B1L/B3L) throughout the year. Weight per shoot was closely related to the number of expanding leaves and was greater in B3L than B1L and B2L, and also greater in summer and autumn than in spring, whereas B1L revealed the greatest young shoot density and highest N concentration. Annual shoot yield and shoot N content were largest in B3L and decreased in the following order: B3L > B2L ≈ B1L/B3L > B1L. However, in the early spring the shoot density, yield, and shoot N content of B1L were much higher than those of B3L. The harvest of B3L significantly reduced the biomass of brown roots and its ratio against the above-ground biomass compared to other harvest standards, suggesting a decreased allocation of carbon to the root system due to seasonal removal. The N dilution curve (N_ys = a × Y_ys^b, where N_ys is the shoot N content and Y_ys is the shoot yield) of spring tea differed markedly from those of summer and autumn teas, suggesting different coordination properties for shoot growth and N supply among the seasons. The annual harvest index (NHI) measured by ¹⁵N traces ranged between 0.18 and 0.23, indicating relatively low N allocation to young shoots, whereby large proportions (58.2–66.9% of the total ¹⁵N absorption) remained in the plant at the end of the experiment. In conclusion, the seasonal distribution of the shoot density, weight per shoot, yield, and N demands vary with harvest standards and highlight the importance of N precision management in tea production to be finely tuned to meet the changes in harvest season and requirements. Full article

(This article belongs to the Special Issue Advances in Tea Plant Biology and Tea Quality Regulation)

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18 pages, 1083 KiB

Open AccessEditor’s ChoiceArticle

Converting Apple Textural Parameters Obtained from Penetrometers and Their Relationships with Sensory Attributes

by Masoumeh Bejaei

Horticulturae 2022, 8(3), 269; https://doi.org/10.3390/horticulturae8030269 - 20 Mar 2022

Cited by 1 | Viewed by 2381

Abstract

Textural attributes of apple impact consumers’ acceptance of the fruit, and are frequently measured by researchers and industry experts to evaluate the fruit quality at different stages of production and marketing. Various instruments are used to conduct these textural evaluations in research and [...] Read more.

Textural attributes of apple impact consumers’ acceptance of the fruit, and are frequently measured by researchers and industry experts to evaluate the fruit quality at different stages of production and marketing. Various instruments are used to conduct these textural evaluations in research and industry settings. The application of different instruments makes the comparison and integration of results extremely difficult. The main objectives of this study were to compare data obtained from three widely used textural instruments, investigate their relationships with each other and with sensory evaluations, and develop models to convert data among instruments. Three penetrometers were included in the study: (1) Fruit Texture Analyzer (FTA); (2) Mohr Digi-Test-2 (MDT-2); and (3) TA.XTplus Texture Analyzer (TA.XTplus). Eight apple varieties with a range of textural attributes were selected. Eleven sensory judges evaluated three apple slices (1/8 apple) from each variety. The instrumental measurements were conducted on 10 apples per instrument from each variety, with two measurements on each apple. Results of principal component analysis indicated that 95.82% of the variation in the texture data could be explained using only two principal components. Linear and nonlinear regression models were developed to convert data obtained from an instrument to those from other instruments. Full article

(This article belongs to the Section Postharvest Biology, Quality, Safety, and Technology)

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16 pages, 1803 KiB

Open AccessEditor’s ChoiceArticle

Integrative Effects of CO₂ Concentration, Illumination Intensity and Air Speed on the Growth, Gas Exchange and Light Use Efficiency of Lettuce Plants Grown under Artificial Lighting

by Hesham A. Ahmed, Yuxin Tong, Lie Li, Suliaman Q. Sahari, Abdulkarem M. Almogahed and Ruifeng Cheng

Horticulturae 2022, 8(3), 270; https://doi.org/10.3390/horticulturae8030270 - 20 Mar 2022

Cited by 6 | Viewed by 3208

Abstract

This study investigates and quantifies the integrative effects of CO₂ concentration (500, 1000 and 1500 µmol mol⁻¹), illumination intensity (100, 200 and 300 μmol m⁻² s⁻¹) and air speed (0.25, 0.50 and 0.75 m s⁻¹) [...] Read more.

This study investigates and quantifies the integrative effects of CO₂ concentration (500, 1000 and 1500 µmol mol⁻¹), illumination intensity (100, 200 and 300 μmol m⁻² s⁻¹) and air speed (0.25, 0.50 and 0.75 m s⁻¹) on the growth, gas exchange and light use efficiency of lettuce plants (Lactuca sativa L.) grown under artificial lighting. The results show that lettuce growth and gas exchange are closely related to CO₂ concentration and illumination intensity, while air speed enhances CO₂ transport during photosynthesis. The most influential two-way interactions were observed between CO₂ concentration and illumination intensity on the fresh and dry weights of lettuce shoots with effect sizes of 34% and 32%, respectively, and on the photosynthesis, transpiration and light use efficiency, with effect sizes of 52%, 47% and 41%, respectively. The most significant three-way interaction was observed for the photosynthetic rate, with an effect size of 51%. In general, the fresh and dry weights of lettuce plants increased by 36.2% and 20.1%, respectively, with an increase in CO₂ concentration from 500 to 1500 µmol mol⁻¹ and by 48.9% and 58.6%, respectively, with an increase in illumination intensity from 100 to 300 μmol m⁻² s⁻¹. The photosynthetic rate was found to be positively correlated with CO₂ concentration, illumination intensity and air speed. The transpiration rate and stomatal conductance increased by 34.9% and 42.1%, respectively, when the illumination intensity increased from 100 to 300 μmol m⁻² s⁻¹. However, as CO₂ concentration increased from 500 to 1500 μmol mol⁻¹ and air speed increased from 0.25 to 0.75 m s⁻¹, the transpiration rate decreased by 17.5% and 12.8%, respectively. With the quantified data obtained, we were able to adequately determine how CO₂ concentration, illumination intensity and air speed interact with their combined effects on the growth of lettuce plants grown in indoor cultivation systems with artificial lighting. Full article

(This article belongs to the Section Vegetable Production Systems)

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20 pages, 5053 KiB

Open AccessEditor’s ChoiceArticle

VIS-NIR Modeling of Hydrangenol and Phyllodulcin Contents in Tea-Hortensia (Hydrangea macrophylla subsp. serrata)

by Marcel Dieter Moll, Liane Kahlert, Egon Gross, Esther-Corinna Schwarze, Maria Blings, Silke Hillebrand, Jakob Ley, Thorsten Kraska and Ralf Pude

Horticulturae 2022, 8(3), 264; https://doi.org/10.3390/horticulturae8030264 - 18 Mar 2022

Cited by 3 | Viewed by 2345

Abstract

Hyperspectral data are commonly used for the fast and inexpensive quantification of plant constituent estimation and quality control as well as in research and development applications. Based on chemical analysis, different models for dihydroisocoumarins (DHCs), namely hydrangenol (HG) and phyllodulcin (PD), were built [...] Read more.

Hyperspectral data are commonly used for the fast and inexpensive quantification of plant constituent estimation and quality control as well as in research and development applications. Based on chemical analysis, different models for dihydroisocoumarins (DHCs), namely hydrangenol (HG) and phyllodulcin (PD), were built using a partial least squares regression (PLSR). While HG is common in Hydrangea macrophylla, PD only occurs in cultivars of Hydrangea macrophylla subsp. serrata, also known as ‘tea-hortensia’. PD content varies significantly over the course of the growing period. For maximizing yield, a targeted estimation of PD content is needed. Nowadays, DHC contents are determined via UPLC, a time-consuming and a destructive method. In this research article we investigated PLSR-based models for HG and PD using three different spectrometers. Two separate trials were conducted to test for model quality. Measurement conditions, namely fresh or dried leaves and black or white background, did not influence model quality. While highly accurate modeling of HG and PD for single plants was not possible, the determination of the mean content on a larger scale was successful. The results of this study show that hyperspectral modeling as a decision support for farmers is feasible and provides accurate results on a field scale. Full article

(This article belongs to the Special Issue Botany, Phytochemistry and Pharmacology in Traditional Herbal Medicine)

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16 pages, 3090 KiB

Open AccessEditor’s ChoiceArticle

Commercial Potato Cultivars Exhibit Distinct Susceptibility to the Root Lesion Nematode Pratylenchus penetrans

by Joana Figueiredo, Paulo Vieira, Isabel Abrantes and Ivânia Esteves

Horticulturae 2022, 8(3), 244; https://doi.org/10.3390/horticulturae8030244 - 12 Mar 2022

Cited by 1 | Viewed by 2557

Abstract

The root lesion nematode Pratylenchus penetrans is an important plant-parasitic nematode of potato. In this study, the susceptibility of commercial potato cultivars to P. penetrans was assessed. Nematode penetration was evaluated in cultivars Agria, Camel, Kennebec, Laura, Royata, and Stemster at 1, 3, [...] Read more.

The root lesion nematode Pratylenchus penetrans is an important plant-parasitic nematode of potato. In this study, the susceptibility of commercial potato cultivars to P. penetrans was assessed. Nematode penetration was evaluated in cultivars Agria, Camel, Kennebec, Laura, Royata, and Stemster at 1, 3, 7, and 15 days after inoculation (DAI) with 750 nematodes/plant, and an egression assay at 3 DAI with 1000 nematodes/plant. Reproduction assays of cultivars Agata, Agria, Camel, Désirée, Dirosso, Kennebec, Laura, Picasso, Royata, and Stemster were performed in 2 L pots inoculated with four P. penetrans/g soil and quantified at 60 DAI. Tenue or moderate root cell browning to advanced necrotic areas were observed after nematode penetration, and the number of nematodes/g of root gradually increased with time of infection. A lower number of deposited eggs and nematodes were observed within the roots of cultivar Laura in all assays comparatively to other cultivars. The susceptibility index (SI) was significantly lower in cultivar Laura (0.4–0.6), followed by cultivars Camel and Picasso (0.8–0.9). All remaining cultivars showed SI values above 1. Although the potato susceptibility to the nematode varied among cultivars, no differences on the average number or weight of tubers produced by each plant of inoculated versus non-inoculated plants were detected. Our data reveals that these cultivars have a distinct ability to support the reproduction of P. penetrans. Full article

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15 pages, 2364 KiB

Open AccessEditor’s ChoiceArticle

A Multicultivar Approach for Grape Bunch Weight Estimation Using Image Analysis

by Gonçalo Victorino, Carlos Poblete-Echeverría and Carlos M. Lopes

Horticulturae 2022, 8(3), 233; https://doi.org/10.3390/horticulturae8030233 - 8 Mar 2022

Cited by 2 | Viewed by 2595

Abstract

The determination of bunch features that are relevant for bunch weight estimation is an important step in automatic vineyard yield estimation using image analysis. The conversion of 2D image features into mass can be highly dependent on grapevine cultivar, as the bunch morphology [...] Read more.

The determination of bunch features that are relevant for bunch weight estimation is an important step in automatic vineyard yield estimation using image analysis. The conversion of 2D image features into mass can be highly dependent on grapevine cultivar, as the bunch morphology varies greatly. This paper aims to explore the relationships between bunch weight and bunch features obtained from image analysis considering a multicultivar approach. A set of 192 bunches from four cultivars, collected at sites located in Portugal and South Africa, were imaged using a conventional digital RGB camera, followed by image analysis, where several bunch features were extracted, along with physical measurements performed in laboratory conditions. Image data features were explored as predictors of bunch weight, individually and in a multiple stepwise regression analysis, which were then tested on 37% of the data. The results show that the variables bunch area and visible berries are good predictors of bunch weight (R² ranging from 0.72 to 0.90); however, the simple regression lines fitted between these predictors and the response variable presented significantly different slopes among cultivars, indicating cultivar dependency. The elected multiple regression model used a combination of four variables: bunch area, bunch perimeter, visible berry number, and average berry area. The regression analysis between the actual and estimated bunch weight yielded a R² = 0.91 on the test set. Our results are an important step towards automatic yield estimation in the vineyard, as they increase the possibility of applying image-based approaches using a generalized model, independent of the cultivar. Full article

(This article belongs to the Special Issue Advances in Viticulture Production)

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13 pages, 2250 KiB

Open AccessEditor’s ChoiceArticle

Decreased Solution pH and Increased K⁺ Uptake Are Related to Ammonium Tolerance in Hydroponically Cultured Plants

by Jinnan Song, Jingli Yang and Byoung Ryong Jeong

Horticulturae 2022, 8(3), 228; https://doi.org/10.3390/horticulturae8030228 - 7 Mar 2022

Cited by 4 | Viewed by 2365

Abstract

The ammonium (NH₄⁺) tolerance of plants is an important issue in agriculture, associated with several plant characteristics. So far, plant tissue acidification has been shown as the primary cause of NH₄⁺ toxicity. Suppressed plant growth caused by excess [...] Read more.

The ammonium (NH₄⁺) tolerance of plants is an important issue in agriculture, associated with several plant characteristics. So far, plant tissue acidification has been shown as the primary cause of NH₄⁺ toxicity. Suppressed plant growth caused by excess NH₄⁺ can be counteracted by potassium (K⁺) application. However, the effects of NH₄⁺ tolerances on the differences regarding pH changes together with K⁺ uptake remain to be determined. Here, we performed an 84 h hydroponic cultivation of five species with different NH₄⁺ tolerances, subjected to three NH₄⁺:NO₃⁻ solutions (0:100, 50:50, or 100:0), to investigate the pH changes and ion uptakes. Consequently, the solution pH was lowered over time to varying extents in the presence of NH₄⁺. The NH₄⁺-tolerant ageratum and lettuce, shown to be tolerant to NH₄⁺ in this trial, rapidly lowered the solution pH, whereas extremely NH₄⁺-sensitive salvia and cabbage only gave a minor decrease in the solution pH when grown with 100:0 NH₄⁺:NO₃⁻. Additionally, the increased external NH₄⁺ level led to a substantial decline in the net cation influxes (K⁺, Ca²⁺, and Mg²⁺). As compared to solely NH₄⁺-fed salvia and cabbage, solely NH₄⁺-fed ageratum and lettuce ultimately showed a relatively greater net K⁺ influx. Taken together, this study discusses how the decreases in pH and K⁺ are related to NH₄⁺ tolerance in five hydroponically cultured species. Full article

(This article belongs to the Special Issue Strategies and Practices of Fertilization Management of Horticultural Crops)

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12 pages, 3281 KiB

Open AccessEditor’s ChoiceArticle

Microalga Biofertilizer Triggers Metabolic Changes Improving Onion Growth and Yield

by Ely Cristina Negrelli Cordeiro, Átila Francisco Mógor, Juliana de Oliveira Amatussi, Gilda Mógor, Gabriel Bocchetti de Lara and Harielly Marianne Costa Marques

Horticulturae 2022, 8(3), 223; https://doi.org/10.3390/horticulturae8030223 - 4 Mar 2022

Cited by 5 | Viewed by 2532

Abstract

Seeking the development of nature-friendly agronomic techniques, the use of natural sources to promote plant growth and increase agricultural yield has gained relevance. In this context, the use of biofertilizers or biostimulants obtained from microalgae has been studied, as these microorganisms have in [...] Read more.

Seeking the development of nature-friendly agronomic techniques, the use of natural sources to promote plant growth and increase agricultural yield has gained relevance. In this context, the use of biofertilizers or biostimulants obtained from microalgae has been studied, as these microorganisms have in their composition a great diversity of bioactive molecules. This study aimed to evaluate the effect of microalga Asterarcys quadricellulare (CCAP 294/1) on organic onion production, verifying its action on metabolism, growth and yield of two cultivars. Thus, two experiments were carried out: (i) foliar applications on onion plants grown in pots in a greenhouse; (ii) foliar applications on field-grown onion under an organic system. Both experiments were undertaken using solutions with spray-dried microalga biomass at concentrations of 0.05, 0.15, 0.25 and 0.4 g L⁻¹. Biometric variables, yield of bulbs and biochemical variables were evaluated indicating that the use of A. quadricellulare promoted plant growth and increases in bulb caliber and yield of both onion cultivars. The microalga biomass stimulated plant metabolism by increases in contents of chlorophyll, carotenoids, amino acids, and the nitrate reductase enzyme activity in leaves, also free amino acids and total sugar contents in bulbs, highlighting the biomass concentration of 0.25 g L⁻¹. Full article

(This article belongs to the Section Plant Nutrition)

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14 pages, 1818 KiB

Open AccessEditor’s ChoiceArticle

Optimization of the Yield, Total Phenolic Content, and Antioxidant Capacity of Basil by Controlling the Electrical Conductivity of the Nutrient Solution

by Xiaowei Ren, Na Lu, Wenshuo Xu, Yunfei Zhuang and Michiko Takagaki

Horticulturae 2022, 8(3), 216; https://doi.org/10.3390/horticulturae8030216 - 1 Mar 2022

Cited by 10 | Viewed by 2955

Abstract

Hydroponic cultivation using nutrient solution (NS) is the main cultivation method employed by plant factories with artificial lighting (PFALs). The electrical conductivity (EC) of NSs influences the yield and quality of vegetables. The purpose of this study was to optimize the yield and [...] Read more.

Hydroponic cultivation using nutrient solution (NS) is the main cultivation method employed by plant factories with artificial lighting (PFALs). The electrical conductivity (EC) of NSs influences the yield and quality of vegetables. The purpose of this study was to optimize the yield and antioxidant accumulation of basil in a PFAL by EC management. In experiment 1, basil plants were grown under four different ECs (0.5, 1.0, 3.0, and 5.0 dS m⁻¹) after transplanting. At 18 days after treatment, the highest levels of shoot fresh and dry weights, leaf fresh and dry weights, and leaf area were observed at an EC of 3.0 dS m⁻¹. However, low-EC treatments (0.5 and 1.0 dS m⁻¹) generated total phenolic content (TPC) and antioxidant capacities that were higher than those of other EC treatments (3.0 and 5.0 dS m⁻¹). In experiment 2, basil plants were grown at an EC of 3.0 dS m⁻¹ for 13 or 15 days, then treated with water or NS with low ECs (0.5 and 1.0 dS m⁻¹) for 5 or 3 days before harvest. The short-term low-EC treatments, especially, water for 3 days and 0.5 dS m⁻¹ for 5 days, significantly increased the TPC and antioxidant capacity of leaves without significantly decreasing the yields of basil, compared with the control. In conclusion, yield of basil was optimized with an EC of 3.0 dS m⁻¹; however, the TPC and antioxidant capacity of basil were significantly increased by low ECs of 0.5 and 1.0 dS m⁻¹. Short-term low-EC treatments (0.5 dS m⁻¹ for 5 days or water for 3 days) could be used to promote the TPC and antioxidant capacity in leaves without sacrificing yield of basil significantly. Full article

(This article belongs to the Special Issue Urban Horticulture - New Trends and Technologies)

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20 pages, 7329 KiB

Open AccessEditor’s ChoiceArticle

The Inclusion of Green Light in a Red and Blue Light Background Impact the Growth and Functional Quality of Vegetable and Flower Microgreen Species

by Matteo Orlando, Alice Trivellini, Luca Incrocci, Antonio Ferrante and Anna Mensuali

Horticulturae 2022, 8(3), 217; https://doi.org/10.3390/horticulturae8030217 - 1 Mar 2022

Cited by 17 | Viewed by 5842

Abstract

Microgreens are edible seedlings of vegetables and flowers species which are currently considered among the five most profitable crops globally. Light-emitting diodes (LEDs) have shown great potential for plant growth, development, and synthesis of health-promoting phytochemicals with a more flexible and feasible spectral [...] Read more.

Microgreens are edible seedlings of vegetables and flowers species which are currently considered among the five most profitable crops globally. Light-emitting diodes (LEDs) have shown great potential for plant growth, development, and synthesis of health-promoting phytochemicals with a more flexible and feasible spectral manipulation for microgreen production in indoor farms. However, research on LED lighting spectral manipulation specific to microgreen production, has shown high variability in how these edible seedlings behave regarding their light environmental conditions. Hence, developing species-specific LED light recipes for enhancement of growth and valuable functional compounds is fundamental to improve their production system. In this study, various irradiance levels and wavelengths of light spectrum produced by LEDs were investigated for their effect on growth, yield, and nutritional quality in four vegetables (chicory, green mizuna, china rose radish, and alfalfa) and two flowers (french marigold and celosia) of microgreens species. Microgreens were grown in a controlled environment using sole-source light with different photosynthetic photon flux density (110, 220, 340 µmol m⁻² s⁻¹) and two different spectra (RB: 65% red, 35% blue; RGB: 47% red, 19% green, 34% blue). At harvest, the lowest level of photosynthetically active photon flux (110 µmol m⁻² s⁻¹) reduced growth and decreased the phenolic contents in almost all species. The inclusion of green wavelengths under the highest intensity showed positive effects on phenolic accumulation. Total carotenoid content and antioxidant capacity were in general enhanced by the middle intensity, regardless of spectral combination. Thus, this study indicates that the inclusion of green light at an irradiance level of 340 µmol m⁻² s⁻¹ in the RB light environment promotes the growth (dry weight biomass) and the accumulation of bioactive phytochemicals in the majority of the microgreen species tested. Full article

(This article belongs to the Special Issue Indoor Farming and Artificial Cultivation)

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26 pages, 2798 KiB

Open AccessEditor’s ChoiceReview

Top Ten Most Important U.S.-Regulated and Emerging Plant-Parasitic Nematodes

by Mihail Kantor, Zafar Handoo, Camelia Kantor and Lynn Carta

Horticulturae 2022, 8(3), 208; https://doi.org/10.3390/horticulturae8030208 - 26 Feb 2022

Cited by 21 | Viewed by 6359

Abstract

Plant-parasitic nematodes (PPNs) are important pests that cause an estimated ten billion dollars of crop loss each year in the United States and over 100 billion dollars globally. The Animal and Plant Health Inspection Service (APHIS) within the U.S. Department of Agriculture maintains [...] Read more.

Plant-parasitic nematodes (PPNs) are important pests that cause an estimated ten billion dollars of crop loss each year in the United States and over 100 billion dollars globally. The Animal and Plant Health Inspection Service (APHIS) within the U.S. Department of Agriculture maintains and updates the U.S. Regulated Plant Pest list. Currently, the number of PPNs regulated by APHIS includes more than 60 different species. This review focuses on the top ten most economically important regulated and emerging plant-parasitic nematodes and summarizes the diagnostics of morphological and some molecular features for distinguishing them. These ten major previously described nematode species are associated with various economically important crops from around the world. This review also includes their current distribution in the U.S. and a brief historical background and updated systematic position of these species. The species included in this review include three PPNs considered by the U.S. Department of Agriculture as invasive invertebrates Globodera pallida, Globodera rostochiensis, and Heterodera glycines; four regulated PPNs, namely Bursaphelenchus xylophilus, Meloidogyne fallax, Ditylenchus dipsaci, and Pratylenchus fallax; and the three emerging PPNs Meloidogyne chitwoodi, Meloidogyne enterolobii, and Litylenchus crenatae mccannii. Full article

(This article belongs to the Special Issue Recent Advance in the Identification and Diagnostics of Plant-Parasitic Nematodes)

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10 pages, 2200 KiB

Open AccessEditor’s ChoiceArticle

Shoot Development through Modified Transverse Thin Cell Layer (tTCL) Culture of Phalaenopsis Hybrid Protocorms

by Kuo-Chin Lo, Jualang Azlan Gansau, Chia-Hung Shih and Chien-Yuan Kao

Horticulturae 2022, 8(3), 206; https://doi.org/10.3390/horticulturae8030206 - 26 Feb 2022

Cited by 3 | Viewed by 2531

Abstract

This first-attempt study used microtome-based methods to generate a thin cell layer culture for the micropropagation of Phal. Hwafeng Redjewel × Phal. New Cinderella. Protocorms were embedded in various agarose concentrations (8–12%, w/v) and dried from 1 to 8 h [...] Read more.

This first-attempt study used microtome-based methods to generate a thin cell layer culture for the micropropagation of Phal. Hwafeng Redjewel × Phal. New Cinderella. Protocorms were embedded in various agarose concentrations (8–12%, w/v) and dried from 1 to 8 h before sectioning with a microtome. Optimal conditions for slicing sections of 100 to 300 μm were achieved when the protocorms were embedded at 10% (w/v) agarose and dried for 4 h under laminar flow, and the hardness of the agarose block under these conditions reached 641.8 ± 9.5 g·cm⁻². The sectioned protocorms that were cultured on an MS medium supplemented with 1.2 mg·L⁻¹ 6-benzylaminopurine and 0.1 mg·L⁻¹ α-naphthaleneacetic acid were capable of growth and differentiated through the neoformation of protocorm-like bodies (PLBs) and/or callus before subsequent regeneration into plantlets and development into healthy plants in a nursery environment. The results of this study demonstrate that microtome-based tTCL is a reliable and promising approach for mass propagation and possible virus-free propagation objectives for Phalaenopsis. Full article

(This article belongs to the Special Issue Advances in Orchid Physiology, Micropropagation, Breeding and Genomics)

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13 pages, 1818 KiB

Open AccessEditor’s ChoiceArticle

Effect of Chitosan-Poly(Acrylic Acid) Complexes and Two Nutrient Solutions on the Growth and Yield of Two Habanero Pepper Cultivars

by Rogelio Enrique Palacios-Torres, Amadeo Santos-Chavez, Hortensia Ortega-Ortiz, Ana Rosa Ramírez-Seañez, José Antonio Yam-Tzec, Adolfo Amador-Mendoza, Antonio Juárez-Maldonado, Maribel Reyes-Osornio and Hipólito Hernández-Hernández

Horticulturae 2022, 8(3), 201; https://doi.org/10.3390/horticulturae8030201 - 24 Feb 2022

Cited by 4 | Viewed by 2117

Abstract

Chitosan (CS) is a natural polymer used in agriculture as a biostimulant that has been evaluated in different plant models. In this study, we evaluated the effect of the foliar application of chitosan–poly(acrylic acid) complexes (CS–PAA) and two nutrient solutions (A and B) [...] Read more.

Chitosan (CS) is a natural polymer used in agriculture as a biostimulant that has been evaluated in different plant models. In this study, we evaluated the effect of the foliar application of chitosan–poly(acrylic acid) complexes (CS–PAA) and two nutrient solutions (A and B) on the parameters of growth and yield of two habanero pepper cultivars (Chichen Itza and Jaguar) in a greenhouse. Over the course of the experiment, eight foliar applications were carried out at 15-day intervals. Our results showed that foliar applications of CS–PAA complexes have a biostimulant effect on the habanero pepper crop by increasing the total dry biomass of the plant and the number of fruits of the two cultivars. Regarding nutrient solutions, the nutrient solution A increased the yield of the Chichen Itza cultivar; this effect was because it had a better balance of potassium and calcium compared to the nutrient solution B. These results provide advances on the use of CS–PAA complexes as a biostimulant and the management of nutrient solutions in the crop of habanero peppers. Full article

(This article belongs to the Special Issue Hydroponics in Vegetable Production)

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17 pages, 4356 KiB

Open AccessEditor’s ChoiceArticle

Research on Mixing Law of Liquid Fertilizer Injected into Irrigation Pipe

by Zhiyang Zhang, Chao Chen, Hong Li and Pan Tang

Horticulturae 2022, 8(3), 200; https://doi.org/10.3390/horticulturae8030200 - 24 Feb 2022

Cited by 6 | Viewed by 2268

Abstract

The time and position that fertilizer takes to uniformly mix with water in an irrigation system significantly affects the development of a fertilization strategy. A pipe irrigation system was used to study the fertilizer–water mixing law in irrigation pipes using numerical simulation and [...] Read more.

The time and position that fertilizer takes to uniformly mix with water in an irrigation system significantly affects the development of a fertilization strategy. A pipe irrigation system was used to study the fertilizer–water mixing law in irrigation pipes using numerical simulation and experiments. The effect of the diameter of the water pipe and fertilizer pipe, water and fertilizer flow rates, concentration and viscosity of fertilizer, frequency of fertilizer injection on the mixing speed, and uniform mixing length indicated that the frequency of fertilizer injection did not affect the mixing process. The increase in the water pipe diameter and fertilizer flow rate or the decrease in fertilizer pipe and water flow rate diameter result in the increase of the speed of fertilizer solution mixing with water along the radial direction of the mixing pipe. The uniform mixing length was directly proportional to the fertilizer pipe diameter, water pipe diameter, water flow rate, and fertilizer viscosity, while it was inversely proportional to the flow rate and concentration of fertilizer. The relationship between the uniform mixing length and six influencing factors was fitted, the fitting was highly accurate, and the fitting equation can be used to predict the uniform mixing length under other conditions. Full article

(This article belongs to the Special Issue Advanced of Horticulture Innovative Irrigation Technologies)

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