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Agronomy, Volume 12, Issue 8 (August 2022) – 253 articles

Cover Story (view full-size image): Insect pests cause considerable losses in agriculture across the planet. The rapid identification of these agents in specific maturity stages, such as early and adult stages, is a promising alternative for crop infestation management. Automatic recognition, using computer vision and machine learning techniques, is an innovative way that has shown high rates of correct answers in insect recognition. However, the algorithms typically require a large dataset for model training and relevant computational capacity. Few-shot learning, however, is a more suitable approach to handle insect classification using few data samples, and a promising alternative for on-site application in crops using embedded devices. View this paper
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12 pages, 1495 KiB  
Article
Monitoring the Bud Mite Pest in a Hazelnut Orchard of Central Italy: Do Plant Height and Irrigation Influence the Infestation Level?
by Mario Contarini, Luca Rossini, Nicolò Di Sora, Enrico de Lillo and Stefano Speranza
Agronomy 2022, 12(8), 1982; https://doi.org/10.3390/agronomy12081982 - 22 Aug 2022
Cited by 6 | Viewed by 1835
Abstract
Mite pests are a serious threat for hazelnut cultivations, causing economic losses every year. At least two species of big bud mites, Phytoptus avellanae (Acari: Phytoptidae) and Cecidophyopsis vermiformis (Acari: Eriophyidae), are involved in severe hazelnut bud infestations, even though few studies report [...] Read more.
Mite pests are a serious threat for hazelnut cultivations, causing economic losses every year. At least two species of big bud mites, Phytoptus avellanae (Acari: Phytoptidae) and Cecidophyopsis vermiformis (Acari: Eriophyidae), are involved in severe hazelnut bud infestations, even though few studies report P. avellanae as the most present and harmful. Great steps forward have been made in monitoring and management strategies of these mite pests, but a plethora of questions remains unanswered about their ecology and behaviour and how agronomical practices impact populations. Given this precondition, we conducted a four-year monitoring in an experimental hazelnut orchard located in the Viterbo hazelnut district, Central Italy, to: (i) explore the potential effect that irrigation has on mite infestations, (ii) assess if mites locate in a particular band height of hazelnut plants; and (iii) assess the overall field infestation over the years. This study showed that not-irrigated plants and plants irrigated by underground pipe systems were similarly infested. Mites tend to locate in the middle band of the plant, namely from 1.5 to 3 m from the ground. The four-year survey showed an overall increasing infestation trend, with a peak in 2021 for irrigated plants and 2022 for not-irrigated. These results are a milestone for further exploration of the biology and ecology of this pest and to formulate ad hoc monitoring and control strategies as well. Full article
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16 pages, 1308 KiB  
Review
Compatible Graft Establishment in Fruit Trees and Its Potential Markers
by Prakash Babu Adhikari, Qiang Xu and Michitaka Notaguchi
Agronomy 2022, 12(8), 1981; https://doi.org/10.3390/agronomy12081981 - 22 Aug 2022
Cited by 6 | Viewed by 3763
Abstract
Plant grafting is a maneuver humans learned from nature and has been practiced since ancient times. The technique has long been applied for efficient propagation as well as for the modification of the traits of interest, such as stress tolerance, tree size, and [...] Read more.
Plant grafting is a maneuver humans learned from nature and has been practiced since ancient times. The technique has long been applied for efficient propagation as well as for the modification of the traits of interest, such as stress tolerance, tree size, and fruit quality. Since grafting can enhance the environmental tolerance and disease resistance of a plant, its techniques are now used not only in tree species but also among vegetables. Despite such wide advantages of grafting, however, the potential cause behind a compatible graft establishment (scion-rootstock connection) is yet to be fully understood. As compared to succulent herbaceous plants, woody plants often take a longer time for the graft-take and the plants may exhibit incompatible/unsuccessful graft-establishment symptoms within a period ranging from months to years. In this review, we discuss factors involved in a successful/compatible graft establishment along with bottlenecks of our understanding and future perspectives in a simplified manner- particularly focusing on incompatible graft formation on fruit trees based on earlier studies in the field. Full article
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20 pages, 4658 KiB  
Article
Irrigation Method and Volume for Korla Fragrant Pear: Impact on Soil Water and Salinity, Yield, and Fruit Quality
by Yao Zhang, Hongguang Liu, Ping Gong, Xinlin He, Jiaxin Wang, Zonglan Wang and Jingrui Zhang
Agronomy 2022, 12(8), 1980; https://doi.org/10.3390/agronomy12081980 - 22 Aug 2022
Cited by 3 | Viewed by 1697
Abstract
A field study in an orchard of Korla fragrant pear tested three levels of irrigation (as varying proportions of evapotranspiration; namely, W1: 70% ETC, W2: 85% ETC, and W3: 100% ETC) and four methods of applying such [...] Read more.
A field study in an orchard of Korla fragrant pear tested three levels of irrigation (as varying proportions of evapotranspiration; namely, W1: 70% ETC, W2: 85% ETC, and W3: 100% ETC) and four methods of applying such irrigation; namely, F1: surface drip, F2: subsurface, F3: root zone infiltration, and CK: flood irrigation (as the control or check). The effects of the different treatments were evaluated in terms of plant growth (shoot length and leaf area), fruit yield and quality, and the distribution of water and salt in soil. For a given method of irrigation, soil moisture content, wet-front displacement, the length of new shoots, and leaf area under W3 were significantly higher than those under W1 and W2. The salt content under W3 was also significantly lower than that under W1 and W2, whereas the yield was significantly higher—by 5.89–13.85% compared to that under W2 and by 4.08–13.13% compared to that under W1. For a given volume of irrigation, yield, water-use efficiency, and fruit quality were significantly higher under F3 and F2 than those under F1. Soil water was more uniformly distributed and its content was significantly higher under F3 than the corresponding values under F1 or F2. The salt content of the root zone was the lowest under F3, and most of the soil salt was in soil layers deeper than 80 cm, but there was no significant difference between F3 and F2 (p < 0.05). There were also no significant differences in shoot length and leaf area among the three irrigation methods (F1, F2, and F3) (p < 0.05). Compared to that under F1, root zone infiltration under W1 was 3.61% greater, that under W2 was 6.58% greater, and that under W3 was 5.43% greater. The irrigation water-use efficiency and production factor efficiency for nitrogen under F3 and F2 were significantly higher than those under F1 (p < 0.05). Principal component analysis showed that the comprehensive score for fruit quality under different volumes of irrigation was the highest under W3, was intermediate under W2, and was the lowest under W1. The corresponding ranking of different irrigation methods was F2, F3, F1, and CK. Comprehensive analysis showed that yield, quality, and the efficiency of utilization of water and fertilizer were higher under the combination W3F3 than under any other combination—therefore, irrigation at 100% of evapotranspiration applied through root zone infiltration is recommended for Korla fragrant pear. The research results can provide a theoretical basis for the optimal use of water and for salt control in pear in Korla, Xinjiang. Full article
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27 pages, 7361 KiB  
Article
Global Sensitivity Analysis of Key Parameters in the APSIMX-Sugarcane Model to Evaluate Nitrate Balance via Treed Gaussian Process
by R. H. K. Rathnappriya, Kazuhito Sakai, Ken Okamoto, Sho Kimura, Tomokazu Haraguchi, Tamotsu Nakandakari, Hideki Setouchi and W. B. M. A. C. Bandara
Agronomy 2022, 12(8), 1979; https://doi.org/10.3390/agronomy12081979 - 22 Aug 2022
Cited by 2 | Viewed by 1820
Abstract
Difficulties in direct monitoring of nitrate balance in agricultural fields reveal the importance of modeling and quantifying the affecting parameters on nitrate balance. We constructed meta-models for APSIMX-Sugarcane using the treed gaussian process and conducted a global sensitivity analysis for nitrate uptake and [...] Read more.
Difficulties in direct monitoring of nitrate balance in agricultural fields reveal the importance of modeling and quantifying the affecting parameters on nitrate balance. We constructed meta-models for APSIMX-Sugarcane using the treed gaussian process and conducted a global sensitivity analysis for nitrate uptake and leaching under three conditions: (1) bare land (BL) to examine the influence of soil hydraulic characteristics, (2) N-free treatment under radiation use efficiency (RUE) ranges (i) 1.2–1.8 [N-free(a)] and (ii) 1.8–2.5 [N-free(b)], and (3) urea conditions to examine the influence of plant growth. Generated meta-models showed good accuracy (for all conditions: R2 > 0.70; NRMSE < 16%; AI > 0.90). The most influential parameters (sensitivity indices ≥ 0.02) were as follows: for leached NO3−N in BL: the parameter rerated to saturated flow-proportion of water between saturation and field capacity (SWCON) of all soil layers; for NO3 uptake and leached NO3−N in N-free(a) and urea: RUE of the phenological stage (PS) 3 (RUE3) and 4, tt_emerg_to_begcane, green_leaf_no, and y_n_conc_crit_leaf of PS 4 (NCL4); in N-free(b): RUE3, NCL4, and SWCON of soil layers 0–15 cm; 15–30 cm, which confirmed that influential parameters were depended on N-stress. The outcomes of this study are useful for enhancing the accuracy and efficiency of crop modeling. Full article
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23 pages, 4253 KiB  
Article
Genome-Wide Identification of GASA Gene Family in Ten Cucurbitaceae Species and Expression Analysis in Cucumber
by Kaijing Zhang, Yuchao Hu, Dekun Yang, Congsheng Yan, Nanyang Li, Ziang Li, Martin Kagiki Njogu, Xing Wang and Li Jia
Agronomy 2022, 12(8), 1978; https://doi.org/10.3390/agronomy12081978 - 22 Aug 2022
Cited by 5 | Viewed by 1914
Abstract
Gibberellic acid-stimulated in Arabidopsis (GASA), a unique small molecular protein of plants, plays an essential role in plant growth and development. The GASA family genes have been identified and studied in many plants. However, the identification of GASA gene family in Cucurbitaceae species [...] Read more.
Gibberellic acid-stimulated in Arabidopsis (GASA), a unique small molecular protein of plants, plays an essential role in plant growth and development. The GASA family genes have been identified and studied in many plants. However, the identification of GASA gene family in Cucurbitaceae species has not been reported yet. Therefore, in this study, based on the available genome information on the Cucurbitaceae species, the GASA family genes in 10 Cucurbitaceae species including cucumber (Cucumis sativus), watermelon (Citrullus lanatus), melon (Cucumis melo), pumpkin (Cucurbita moschata), wax gourd (Benincasa hispida), sponge gourd (Luffa cylindrica), bottle gourd (Lagenaria siceraria), bitter gourd (Momordica charantia), chayote (Sechium edule), and snake gourd (Trichosanthes anguina) were identified with bioinformatics methods. To understand the molecular functions of GASA genes, the expression pattern analysis of cucumber GASA family genes in different tissues and stress responses were also analyzed. The results showed that a total of 114 GASA genes were identified in the 10 Cucurbitaceae species, which were divided into three subfamilies. Synteny analysis of GASA genes among cucumber, Arabidopsis and rice showed that nine cucumber GASA genes were colinear with 12 Arabidopsis GASA genes, and six cucumber GASA genes were colinear with six rice GASA genes. The cis-acting elements analysis implied that the cucumber GASA genes contained many cis-elements associated with stress and hormone response. Tissue-specific expression analysis of cucumber GASA family genes revealed that only the CsaV3_2G029490 gene was lowly or not expressed in all tissues, the CsaV3_3G041480 gene was highly expressed in all tissues, and the other seven GASA genes showed tissue-specific expression patterns. Furthermore, nine cucumber GASA family genes exhibited different degrees of regulatory response under GA, abiotic and biotic stresses. Two cucumber GASA genes, CsaV3_3G042060 and CsaV3_3G041480, were differentially expressed under multiple biotic and abiotic stresses, which indicated that these two GASA genes play important roles in the growth and development of cucumber. Full article
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11 pages, 31270 KiB  
Article
The Solanum torvum Transcription Factor StoWRKY6 Mediates Resistance against Verticillium Wilt
by Yu Zhang, Lei Shen, Liangjun Li and Xu Yang
Agronomy 2022, 12(8), 1977; https://doi.org/10.3390/agronomy12081977 - 22 Aug 2022
Cited by 1 | Viewed by 1435
Abstract
WRKY is a transcription factor family that has attracted much attention in recent studies of plant disease resistance, but there are few reports in the study of eggplant resistance to Verticillium wilt. Here, we retrieved an up-regulated WRKY transcription factor, StoWRKY6, from [...] Read more.
WRKY is a transcription factor family that has attracted much attention in recent studies of plant disease resistance, but there are few reports in the study of eggplant resistance to Verticillium wilt. Here, we retrieved an up-regulated WRKY transcription factor, StoWRKY6, from the transcriptome sequencing data of Solanum torvum response to Verticillium dahliae infection. Phylogenetic analyses revealed the highest homology species of StoWRKY6 in the WRKY family is Solanum melongena. Based on the quantitative real-time PCR analysis, StoWRKY6 was highly expressed in the roots but barely expressed in the leaves. Transient expressions of StoWRKY6 in Nicotiana benthamiana showed a nuclear localization. A virus-mediated gene silencing experiment indicated that the silencing of StoWRKY6 reduced the resistance to Verticillium wilt in Solanum torvum. To further verify the immune response function, we introduced StoWRKY6 into Nicotiana benthamiana using transient transformation technology and found obvious spots under UV light. In summary, these results showed that StoWRKY6 played an important role in the resistance to Verticillium wilt of Solanum torvum, which may function mainly by inducing an immune response. Our study provided strong evidence for the mechanism of eggplant resistance to Verticillium wilt and laid a foundation for the potential molecular breeding of eggplant disease resistance. Full article
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18 pages, 6592 KiB  
Article
Genome-Wide Identification of Long Non-Coding RNAs in Pearl Millet (Pennisetum glaucum (L.)) Genotype Subjected to Drought Stress
by Baibhav Kumar, Animesh Kumar, Sarika Jaiswal, Mir Asif Iquebal, Ulavappa B. Angadi, Rukam S. Tomar, Anil Rai and Dinesh Kumar
Agronomy 2022, 12(8), 1976; https://doi.org/10.3390/agronomy12081976 - 22 Aug 2022
Cited by 1 | Viewed by 2239
Abstract
Pearl millet (Pennisetum glaucum L.) is affected by drought stress, affecting crop productivity and survival. Long non-coding RNAs (lncRNAs) are reported to play a vital role in the response to drought stress. LncRNAs represent a major part of non-protein coding RNAs and [...] Read more.
Pearl millet (Pennisetum glaucum L.) is affected by drought stress, affecting crop productivity and survival. Long non-coding RNAs (lncRNAs) are reported to play a vital role in the response to drought stress. LncRNAs represent a major part of non-protein coding RNAs and are present prevalently. These are involved in various biological processes, which may functionally act as RNA rather than getting transcribed as protein. We targeted genome-wide identification of lncRNAs in pearl millet from root and leaf tissues subjected to drought stress. A total of 879 lncRNAs were identified, out of which 209 (leaf control, root control), 198 (leaf treated, root treated), 115 (leaf control, leaf treated) and 194 (root control, root treated) were differentially expressed. Two lncRNAs were found as potential target mimics of three miRNAs from the miRBase database. Gene ontology study revealed that drought-responsive lncRNAs are involved in biological processes like ‘metabolic process’ and ‘cellular process’, molecular functions like ‘binding’ and ‘catalytic activities’ and cellular components like ‘cell’, ‘cell part’ and ‘membrane part’. LncRNA-miRNA-mRNA network shows that it plays a vital role in the stress-responsive mechanism through their activities in hormone signal transduction, response to stress, response to auxin and transcription factor activity. Only four lncRNAs were found to get a match with the lncRNAs present in the plant lncRNA database CANTATAdb, which shows its poorly conserved nature among species. This information has been cataloged in the pearl millet drought-responsive long non-coding RNA database (PMDlncRDB). The discovered lncRNAs can be used in the improvement of important traits, as well as CISPR-Cas technology, in the editing of ncRNAs in plants for trait improvement. Such a study will increase our understanding of the expression behavior of lncRNAs, as well as its underlying mechanisms under drought stress in pearl millet. Full article
(This article belongs to the Special Issue Improvement of Crops: Current Status and Future Prospects)
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23 pages, 1942 KiB  
Article
Seed Soaking with Sodium Selenate as a Biofortification Approach in Bread Wheat: Effects on Germination, Seedling Emergence, Biomass and Responses to Water Deficit
by Luís Rocha, Ermelinda Silva, Ivo Pavia, Helena Ferreira, Carlos Matos, José M. Osca, José Moutinho-Pereira and José Lima-Brito
Agronomy 2022, 12(8), 1975; https://doi.org/10.3390/agronomy12081975 - 21 Aug 2022
Cited by 2 | Viewed by 2090
Abstract
Selenium (Se) biofortification by seed treatments has been poorly explored in wheat due to the difficulties in establishing seed treatments without compromising plant productive traits. We investigated the effects of Se seed soaking as a pre-sowing treatment in bread wheat. Five soaking periods [...] Read more.
Selenium (Se) biofortification by seed treatments has been poorly explored in wheat due to the difficulties in establishing seed treatments without compromising plant productive traits. We investigated the effects of Se seed soaking as a pre-sowing treatment in bread wheat. Five soaking periods and six Se concentrations were assessed on germination and seedling traits and compared to unsoaked seeds. Twelve hours of soaking was found beneficial for most tested Se concentrations. Then, we evaluated the effects of untreated, 0, 2.5 and 25 mM Se in 12 h seed soaking treatments along the wheat crop cycle under water-deficit (WD) and well-watered (WW) conditions in a pot experiment. Our results evidenced that 12 h of 2.5 mM Se soaking did not affect the germination percentage, and speed-up seedling emergence resulted in a considerable Se seed uptake. These plants also displayed enhanced antioxidant capacity and vegetative biomass accumulation, especially under WD. The treatment with 25 mM of Se negatively affected aerial biomass, suggesting potential toxicity. Physiological responses of Se-treated plants remained unchanged, as well as grain traits. Altogether, we propose that 12 h soaking with 2.5 mM Se is a promissory pre-sowing approach to enrich bread wheat grain and straw, particularly under water-limited environments. Full article
(This article belongs to the Special Issue Effective Methods for Improving Seed Germination and Seed Quality)
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21 pages, 2748 KiB  
Review
Effects of Living Grass Mulch on Soil Properties and Assessment of Soil Quality in Chinese Apple Orchards: A Meta-Analysis
by Wenzheng Tang, Haosheng Yang, Wene Wang, Chunxia Wang, Yaoyue Pang, Dianyu Chen and Xiaotao Hu
Agronomy 2022, 12(8), 1974; https://doi.org/10.3390/agronomy12081974 - 21 Aug 2022
Cited by 10 | Viewed by 2629
Abstract
Soil degradation has exacerbated the gap between crop yield and increasing food demands, and unreasonable field management is one of the main reasons for soil degradation. As a classic orchard soil management mode, living grass mulch can effectively change the hydrothermal environment and [...] Read more.
Soil degradation has exacerbated the gap between crop yield and increasing food demands, and unreasonable field management is one of the main reasons for soil degradation. As a classic orchard soil management mode, living grass mulch can effectively change the hydrothermal environment and soil physicochemical properties of the ‘soil–vegetation–atmosphere’ microclimate of apple orchards. However, these improvement effects are mainly affected by climatic conditions, mulch methods, vegetation varieties and continuous grass-growing years. To evaluate the different effects of living grass mulch and the main influencing factors on soil physicochemical properties of apple orchards in China, in this study, we conducted a meta-analysis using data from 53 peer-reviewed publications to carry out soil quality assessment. The results showed that compared with clear tillage, continuous living grass mulch in apple orchards could improve soil function and performance by about 56% and increase soil enzyme activities by 10–120%, on average, whereas the soil organic matter under the effect of artificial grass and natural grass significantly increased by 29.6% and 14.6%, respectively. Artificial grass in temperate and warm, temperate, semi-humid climate regions had a greater overall improvement effect on the soil physicochemical environment than natural grass. Clover was found to be the most suitable for planting in apple orchards in temperate, semi-humid climate regions, whereas both clover and ryegrass were the best choices in warm, temperate, semi-humid climate regions. The interaction effects of different soil physicochemical properties in apple orchards in warm, temperate, semi-humid climate regions were greater than those in warm, temperate, arid climates and temperate, semi-humid climate regions. The response sensitivity of soil organic matter, organic carbon, urease, catalase, sucrose and cellulase to the living grass mulch effect of apple orchards was greater than that of other soil properties. Full article
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17 pages, 1716 KiB  
Article
At Which Spatial Scale Does Crop Diversity Enhance Natural Enemy Populations and Pest Control? An Experiment in a Mosaic Cropping System
by Coline C. Jaworski, Eva Thomine, Adrien Rusch, Anne-Violette Lavoir, Chunli Xiu, Di Ning, Yanhui Lu, Su Wang and Nicolas Desneux
Agronomy 2022, 12(8), 1973; https://doi.org/10.3390/agronomy12081973 - 21 Aug 2022
Cited by 2 | Viewed by 1931
Abstract
The importance of plant richness to enhance the presence, biodiversity and efficiency of natural enemies in agricultural systems has largely been studied and demonstrated these last decades. Planting and preserving non-crop plants or manipulating crop richness in fields are practices that have proven [...] Read more.
The importance of plant richness to enhance the presence, biodiversity and efficiency of natural enemies in agricultural systems has largely been studied and demonstrated these last decades. Planting and preserving non-crop plants or manipulating crop richness in fields are practices that have proven their efficiency. However, the impact of crop-richness continuity in space and time on pests and natural enemies at a landscape scale remains poorly studied. In a two-year study, we assessed the effect of crop richness (single crop vs. multiple crops) on pest and natural enemy abundance and spillover in a field experiment in north-east China. Overall, we found crop diversity had a limited impact on pest and natural enemy abundance at the spatial scale tested (0.025 vs. 0.2 ha). The total pest and natural enemy abundances were not different between single-crop and multi-crop plots in either year, and the community composition at the functional group level was mostly determined by the crop but not crop diversity. However, we found that crop diversity influenced the numeric response of ladybirds to aphids in wheat; their negative response (higher abundance where aphid abundance was lower, suggesting predation) was attenuated in multi-crop plots (no correlation of aphid and ladybird abundance, suggesting the use of alternative resources). This pattern was not found in maize. Finally, crop succession enhanced the spillover of ladybirds from wheat and maize to cotton plots but with limited benefits for aphid control. Because of these limited impacts, we hypothesized that crop diversity may benefit natural enemy populations and enhance pest control at larger spatial scales; while we found similar abundances of ladybirds between our small (0.025–0.2 ha) plots and in large (2 ha) close-by cotton fields, aphid abundances were more than ten times higher in large cotton fields. Our study highlights the need to accurately estimate the spatial scale at which crop biodiversity may benefit pest control, in relation to the ecology of the target pest and natural enemies. Full article
(This article belongs to the Special Issue Ecological Management of Pests)
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20 pages, 23328 KiB  
Article
Remote Sensing-Based Evaluation of Heat Stress Damage on Paddy Rice Using NDVI and PRI Measured at Leaf and Canopy Scales
by Jae-Hyun Ryu, Dohyeok Oh, Jonghan Ko, Han-Yong Kim, Jong-Min Yeom and Jaeil Cho
Agronomy 2022, 12(8), 1972; https://doi.org/10.3390/agronomy12081972 - 20 Aug 2022
Cited by 4 | Viewed by 2247
Abstract
Extremely high air temperature at the heading stage of paddy rice causes a yield reduction due to the increasing spikelet sterility. Quantifying the damage to crops caused by high temperatures can lead to more accurate estimates of crop yields. The remote sensing technique [...] Read more.
Extremely high air temperature at the heading stage of paddy rice causes a yield reduction due to the increasing spikelet sterility. Quantifying the damage to crops caused by high temperatures can lead to more accurate estimates of crop yields. The remote sensing technique evaluates crop conditions indirectly but provides information related to crop physiology, growth, and yield. In this study, we aim to assess the crop damage caused by heat stress in paddy rice examined under elevated air temperatures in a temperature gradient field chamber from 2016 to 2019, using remote-sensed vegetation indices. A leaf-spectrometer, field-spectrometers, and a multi-spectral camera were used to monitor the conditions of paddy rice. Although, in the leaf- and canopy-scales, the values of normalized difference vegetation index (NDVI) and photochemical reflectance index (PRI) decreased after the heading of rice under normal conditions, the decreasing sensitivity of NDVI and PRI was different depending on the degree of physiological heat stress by high temperature conditions. The NDVI after the heading under extremely high air temperature was not dropped and remained the value before heading. The PRI decreased at all air temperature conditions after the heading; the PRI of the plot exposed to the elevated air temperature was higher than that under ambient air temperature. Further, the relative change in NDVI and PRI after the heading exhibited a strong relationship with the ripening ratio of paddy rice, which is the variable related to crop yield. These remote-sensing results aid in evaluating the crop damage caused by heat stress using vegetation indices. Full article
(This article belongs to the Special Issue Advances in Field Spectroscopy in Agriculture)
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18 pages, 1920 KiB  
Article
Chlorpyrifos Removal in an Artificially Contaminated Soil Using Novel Bacterial Strains and Cyclodextrin. Evaluation of Its Effectiveness by Ecotoxicity Studies
by Alba Lara-Moreno, Esmeralda Morillo, Francisco Merchán, Fernando Madrid and Jaime Villaverde
Agronomy 2022, 12(8), 1971; https://doi.org/10.3390/agronomy12081971 - 20 Aug 2022
Cited by 6 | Viewed by 1821
Abstract
The removal of chlorpyrifos (CLP) from the environment is a matter of general interest, because it is one of the most widely used insecticides in the world but presents a high toxicity and persistence in the environment. Biological strategies are considered as a [...] Read more.
The removal of chlorpyrifos (CLP) from the environment is a matter of general interest, because it is one of the most widely used insecticides in the world but presents a high toxicity and persistence in the environment. Biological strategies are considered as a good option to remediate different environmental compartments. Assisted natural attenuation was used to find the ability of different kinds of soils to mineralise CLP. In this way, two soils showed the capacity to degrade CLP (R and LL up to 47.3% and 61.4% after 100 d, respectively). Thus, two CLP-degrading strains, Bacillus megaterium CCLP1 and Bacillus safensis CCLP2 were isolated from them, showing the capacity to degrade up to 99.1 and 98.9% of CLP in a solution with an initial concentration of 10 mg L−1 after 60 d. Different strategies were considered for increasing the effectiveness of soil bioremediation: (i) biostimulation, using a nutrients solution (NS); (ii) bioaugmentation, using B. megaterium CCLP1 or B. safensis CCLP2; (iii) bioavailability enhancement, using randomly methylated β-cyclodextrin (RAMEB), a biodegradable compound. When bioaugmentation and RAMEB were jointly inoculated and applied, the best biodegradation results were achieved (around 70%). At the end of the biodegradation assay, a toxicity test was used to check the final state of the bioremediated soil, observing that when the degrading strains studied were individually inoculated into the soil, the toxicity was reduced to undetectable levels. Full article
(This article belongs to the Special Issue Impact of Agrochemicals on Soil)
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11 pages, 5903 KiB  
Article
Vernacular Names and Genetics of Cultivated Coffee (Coffea arabica) in Yemen
by Christophe Montagnon, Veronica Rossi, Carolina Guercio and Faris Sheibani
Agronomy 2022, 12(8), 1970; https://doi.org/10.3390/agronomy12081970 - 20 Aug 2022
Cited by 6 | Viewed by 5290
Abstract
While Ethiopia and South Sudan are the native habitats for Coffea arabica, Yemen is considered an important domestication center for this coffee species as most Arabica coffee grown around the world can be traced back to Yemen. Furthermore, climatic conditions in Yemen [...] Read more.
While Ethiopia and South Sudan are the native habitats for Coffea arabica, Yemen is considered an important domestication center for this coffee species as most Arabica coffee grown around the world can be traced back to Yemen. Furthermore, climatic conditions in Yemen are hot and extremely dry. As such, Yemeni coffee trees likely have genetic merits with respect to climate resilience. However, until recently, very little was known about the genetic landscape of Yemeni coffee. The Yemeni coffee sector identifies coffee trees according to numerous vernacular names such as Udaini, Tufahi or Dawairi. However, the geographical landscape of these names and their correlation with the genetic background of the coffee trees have never been explored. In this study, we investigated the geographic occurrence of vernacular names in 148 coffee farms across the main coffee areas of Yemen. Then, we used microsatellite markers to genotype 88 coffee trees whose vernacular name was ascertained by farmers. We find a clear geographical pattern for the use of vernacular coffee names. However, the vernacular names showed no significant association with genetics. Our results support the need for a robust description of different coffee types in Yemen based on their genetic background for the benefit of Yemeni farmers. Full article
(This article belongs to the Section Crop Breeding and Genetics)
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16 pages, 2782 KiB  
Article
Seed Characteristics Affect Low-Temperature Stress Tolerance Performance of Rapeseed (Brassica napus L.) during Seed Germination and Seedling Emergence Stages
by Tao Luo, Ziwei Sheng, Chunni Zhang, Qin Li, Xiaoyan Liu, Zhaojie Qu and Zhenghua Xu
Agronomy 2022, 12(8), 1969; https://doi.org/10.3390/agronomy12081969 - 20 Aug 2022
Cited by 4 | Viewed by 1707
Abstract
Screening and breeding elite varieties with rapid germination and uniform seedling emergence under low temperature is an effective strategy to deal with the cold climate occurring under late sowing conditions in the Yangtze River basin. This study focused on the performance of seven [...] Read more.
Screening and breeding elite varieties with rapid germination and uniform seedling emergence under low temperature is an effective strategy to deal with the cold climate occurring under late sowing conditions in the Yangtze River basin. This study focused on the performance of seven functional traits, including percentage of germination, percentage of emergence, mean germination time, mean emergence time, total seedling length, total dry weight, and seedling vigor index of 436 natural rapeseed populations under normal-temperature (25/20 °C) and low-temperature (15/10 °C) conditions. Furthermore, ten genotypes were screened to verify their low-temperature tolerance based on cultivar traits in a pot experiment. The results show that the germination- and emergence-related functional traits of rapeseed genotypes exhibit rich genotypic diversity in response to low-temperature stress; the variation among these traits ranged from 1–25% under normal-temperature and 10–49% under low-temperature conditions. Variation in seed characteristics also affected the capacity for low-temperature tolerance in the process of seed germination and seedling emergence, and could explain 22% of the total variance for low-temperature stress tolerance indices. There existed high correlations between the stress tolerance index of total dry weight (STI_TDW) and thousand-seed weight, and between the stress tolerance index of emergence percentage (STI_PE) and oil content. The contents of erucic acid, glucosinolate, and eicosenoic acid were positively correlated with the stress tolerance index of mean germination time (STI_MGT) and mean emergence time (STI_MET). The D-CRITIC (distance-based intercriteria correlation) weight method was selected in this experiment to calculate each variety’s comprehensive low-temperature stress tolerance index by integrating the standard deviation and distance correlation coefficient of each index. The genotypes with large comprehensive low-temperature stress tolerance index also had higher low-temperature stress tolerance index of biomass and yield in the pot experiment, indicating that the comprehensive low-temperature stress tolerance index has high reliability and applicability. This study could provide a theoretical basis for the utilization of low-temperature-tolerant germplasm resources, as well as a reference for the cold resistance and yield stability under late- and direct-sowing conditions of rapeseed in the Yangtze River basin and other similar environments around the world. Full article
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20 pages, 4547 KiB  
Article
Molecular Phylogenetic Analysis of Salt-Tolerance-Related Genes in Root-Nodule Bacteria Species Sinorhizobium meliloti
by Victoria Spartakovna Muntyan and Marina Lvovna Roumiantseva
Agronomy 2022, 12(8), 1968; https://doi.org/10.3390/agronomy12081968 - 20 Aug 2022
Cited by 3 | Viewed by 1852
Abstract
A molecular phylogenetic analysis of salt-tolerance-related genes was carried out using complete genome sequencing data available for 26 Sinorhizobium meliloti strains and for 25 bacterial strains belonging to 17 genera. It was revealed that the genes of the first and the second stages [...] Read more.
A molecular phylogenetic analysis of salt-tolerance-related genes was carried out using complete genome sequencing data available for 26 Sinorhizobium meliloti strains and for 25 bacterial strains belonging to 17 genera. It was revealed that the genes of the first and the second stages of the response to salt stress (aqpZ, trkH, and trkA, and betICBA) have copies of many of the above- indicated genes on pSymA. Data obtained can provide evidence that this replicon, known to be essential for nitrogen fixation rhizobia activity, also has a significant role in the formation of a stress-related gene pool. The closest putative phylogenetic relatives were identified for all 14 tested genes and these are the first insights into the evolutionary pathways for the formation of a stress-related gene pool in root nodule nitrogen-fixing bacteria. Full article
(This article belongs to the Special Issue Rhizobial Symbiosis in Crop Legumes: Molecular and Cellular Aspects)
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18 pages, 2289 KiB  
Article
Vine Physiology, Yield Parameters and Berry Composition of Sangiovese Grape under Two Different Canopy Shapes and Irrigation Regimes
by Gabriele Valentini, Chiara Pastore, Gianluca Allegro, Riccardo Mazzoleni, Fabio Chinnici and Ilaria Filippetti
Agronomy 2022, 12(8), 1967; https://doi.org/10.3390/agronomy12081967 - 20 Aug 2022
Cited by 4 | Viewed by 1738
Abstract
Vitis vinifera L. adapts well to a scarce availability of water in the soil. However, in recent decades, the combination of thermal stress with prolonged water scarcity could have dramatic consequences on the vine’s physiological status. In this paper, we evaluated the effects [...] Read more.
Vitis vinifera L. adapts well to a scarce availability of water in the soil. However, in recent decades, the combination of thermal stress with prolonged water scarcity could have dramatic consequences on the vine’s physiological status. In this paper, we evaluated the effects of two canopy shapes and two irrigation regimes at veraison on vine physiology, yield parameters and grape composition through biochemical and molecular approaches. The water shortage strongly influenced the physiology of Sangiovese only when the stress was moderate to severe. Neither the water stress limited to veraison nor the canopy shape were able to influence the yield parameters and sugar content, and a strong induction of the expression of the genes involved in the biosynthesis of anthocyanins was recorded only in conditions of moderate-to-severe stress. This phenomenon led to an increase in the anthocyanin content in berry skins until the end of veraison. Conversely, no significant effects occurred in terms of biochemical and molecular performance after re-watering and at harvest. Though the shape of the canopy could play a role only under elevated temperature and prolonged drought, severe water stress can affect the vine physiology and berry ripening during the veraison stage. Full article
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12 pages, 3035 KiB  
Article
Diversity in Acidity between Core and Pulp of Asian Pear Fruit Is Mainly Regulated by the Collaborative Activity of PH8.1 and DIC2 Genes during Fruit Development
by Shariq Mahmood Alam, Dong-Hai Liu, Muhammad Ateeq, Han Han, Huan Chen, Muhammad Abbas Khan, Yin Luo, Xue-Ling Chen and Yong-Zhong Liu
Agronomy 2022, 12(8), 1966; https://doi.org/10.3390/agronomy12081966 - 20 Aug 2022
Cited by 1 | Viewed by 1773
Abstract
The pear (Pyrus pyrifolia) is an important accessory fruit in which the pear core is tarter than the pear pulp. However, the reason for the acidic core and diversity in the taste of the same fruit is not clear. In this [...] Read more.
The pear (Pyrus pyrifolia) is an important accessory fruit in which the pear core is tarter than the pear pulp. However, the reason for the acidic core and diversity in the taste of the same fruit is not clear. In this study, we observed that the citrate contents were three times higher in the core than in the pulp, while the malate content decreased along with fruit development and was significantly lower in the core than in the pulp at 110 days after flowering. Overall transcript levels for citrate-malate synthesis-related genes increased more in the pear core than the pulp at early fruit development, while degradation-related genes activity was nearly similar or non-significant between the core and pulp during fruit development. The lesser malate accumulation in the pear core compared to the pulp at 110 DAF was possibly due to the reduced activity of tDT2 gene. Regarding citrate accumulation, we identified five important p-type H+-ATPase genes in pear and found that the relative expression level of the PH8.1 gene was four-fold higher in the core than in the pulp during fruit development. Moreover, the expression level of di-carboxylate carrier gene 2 (DIC2) was constantly and significantly higher in the core than in the pulp. In addition, correlation analysis signified that the transcript levels of the two genes PH8.1 and DIC2 positively and significantly correlated with the citrate contents. These results suggested that the increased and collaborative activity of PH8.1 and DIC2 played a key role in the higher citrate accumulation in the core than the pulp, thus, with the help of molecular breeding tools, the citrate contents can be optimized in pear fruit for divers and improved fruit flavoring. Full article
(This article belongs to the Special Issue Omics Approaches and Applications in Fruit Crops Improvement)
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15 pages, 2553 KiB  
Article
Machine Learning-Based Hyperspectral and RGB Discrimination of Three Polyphagous Fungi Species Grown on Culture Media
by Jan Piekarczyk, Andrzej Wójtowicz, Marek Wójtowicz, Jarosław Jasiewicz, Katarzyna Sadowska, Natalia Łukaszewska-Skrzypniak, Ilona Świerczyńska and Katarzyna Pieczul
Agronomy 2022, 12(8), 1965; https://doi.org/10.3390/agronomy12081965 - 20 Aug 2022
Cited by 2 | Viewed by 1820
Abstract
In this study, three fungi species (Botrytis cinerea, Rhizoctonia solani, Sclerotinia sclerotiorum) were discriminated using hyperspectral and red-green-blue (RGB) data and machine learning methods. The fungi were incubated at 25 °C for 10 days on potato dextrose agar in Petri dishes. [...] Read more.
In this study, three fungi species (Botrytis cinerea, Rhizoctonia solani, Sclerotinia sclerotiorum) were discriminated using hyperspectral and red-green-blue (RGB) data and machine learning methods. The fungi were incubated at 25 °C for 10 days on potato dextrose agar in Petri dishes. The Hyperspectral data were acquired using an ASD spectroradiometer, which measures reflectance with 3 and 10 nm bandwidths over the range 350–1000 nm and the range 1000–2500 nm, respectively. The RGB images were collected using a digital Canon 450D camera equipped with the DIGIC 3 processor. The research showed the possibility of distinguishing the analysed fungi species based on hyperspectral curves and RGB images and assessing this differentiation using machine learning statistical methods (extreme boosting machine with bootstrap simulation). The best results in analysed fungi discrimination based on hyperspectral data were achieved using the Principal Component Analysis method, in which the average values of recognition and accuracy for all three species were 0.96 and 0.93, respectively. The wavelengths of the shortwave infrared (SWIR) wavelength region appeared to be the most effective in distinguishing B. cinerea-R. solani and B. cinerea-S. sclerotiorum, while of the visible range (VIS) of electromagnetic spectrum in discrimination of R. solani-S. sclerotiorum. The hyperspectral reflectance data were strongly correlated with the intensity of the pixels in the visible range (R2 = 0.894–0.984). The RGB images proved to be successfully used primarily for the identification of R. solani (recognition = 0.90, accuracy = 0.79) and S. sclerotiorum (recognition = 0.84, accuracy = 0.76). The greatest differences in the intensity of the pixels between B. cinerea and R. solani as well as R. solani and S. sclerotiorum occurred in the blue band and in distinguishing B. cinerea and S. sclerotiorum in the red band. Full article
(This article belongs to the Section Pest and Disease Management)
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21 pages, 2291 KiB  
Article
How Well Can Reflectance Spectroscopy Allocate Samples to Soil Fertility Classes?
by Rong Zeng, David G. Rossiter, Jiapeng Zhang, Kai Cai, Weichang Gao, Wenjie Pan, Yuntao Zeng, Chaoying Jiang and Decheng Li
Agronomy 2022, 12(8), 1964; https://doi.org/10.3390/agronomy12081964 - 20 Aug 2022
Cited by 2 | Viewed by 1590
Abstract
Fertilization decisions depend on the measurement of a large set of soil fertility indicators, usually through laboratory determination, which is costly and time-consuming. Visible and near-infrared (vis-NIR) spectroscopy combined with machine learning can simultaneously predict various soil fertility indicators. Spectroscopy is inherently less [...] Read more.
Fertilization decisions depend on the measurement of a large set of soil fertility indicators, usually through laboratory determination, which is costly and time-consuming. Visible and near-infrared (vis-NIR) spectroscopy combined with machine learning can simultaneously predict various soil fertility indicators. Spectroscopy is inherently less accurate than direct laboratory determination. However, in many fertilization recommendation contexts, farmers mainly fertilize according to classified fertility indicators, rather than by continuous soil property values. These classes have defined limits of property values. We hypothesized that the additional inaccuracy from spectroscopy may not be important for properties grouped into classes. This study compared the indirect and direct prediction of soil fertility classes. Indirectly, by (1) using vis-NIR spectra with machine learning to predict 20 soil fertility indicators (pH, soil organic matter (SOM), cation exchange capacity (CEC), total nitrogen (TN), total phosphorus (TP), total potassium (TK), alkali-hydrolyzable nitrogen (AN), available phosphorus (AP), available potassium (AK), calcium (Ca), magnesium (Mg), silicon (Si), sulfur (S), boron (B), iron (Fe), manganese (Mn), copper (Cu), Zinc (Zn), molybdenum (Mo) and chlorine (Cl)) and (2) allocating the indicators to soil fertility classes. Directly, by predicting soil fertility classes directly from vis-NIR spectra using machine learning. The prediction accuracy of these two methods were compared and the accuracies needed for the acceptable class allocation of the fertility indicators were determined. The example dataset is a soil spectral library from the Guizhou Province, southwest China. The model performance was evaluated by the overall allocation accuracy and tau index, which accounts for class imbalance. For direct allocation based on three fertility classes (low, medium and high), the overall allocation accuracy of eight properties (CEC, Cu, Si, Zn, S, Mn, Ca and Mg), nine properties (B, AN, TK, AK, SOM, TN, TP, Fe and Mo) and three properties (Cl, AP and pH) were within the range of 0.80–1.0, 0.60–0.80 and 0.40–0.60, respectively. For indirect allocation based on the same classes, the allocation accuracy of nine properties (TN, CEC, Cu, S, Zn, Si, Mn, Ca and Mg), nine properties (B, TK, pH, TP, AK, AN, Fe, Mo and SOM) and two properties (Cl and AP) were within the range of 0.80–1.0, 0.60–0.80 and 0.40–0.60, respectively. We conclude that vis-NIR spectroscopy was fairly successful for soil fertility class allocation for most of the soil properties, using either direct or indirect models. The advantage of indirect models is that both specific property values and soil fertility classes can be obtained at no increase in cost, while direct models are suggested when only soil fertility class information are available. Full article
(This article belongs to the Special Issue Soil Sustainability in the Anthropocene)
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15 pages, 2398 KiB  
Article
Comparing Selection Criteria to Select Grapevine Clones by Water Use Efficiency
by Andreu Mairata, Ignacio Tortosa, Cyril Douthe, José Mariano Escalona, Alicia Pou and Hipólito Medrano
Agronomy 2022, 12(8), 1963; https://doi.org/10.3390/agronomy12081963 - 19 Aug 2022
Cited by 5 | Viewed by 1535
Abstract
The current climate change is forcing growth-adapted genotypes with a higher water use efficiency (WUE). However, the evaluation of WUE is being made by different direct and indirect parameters such as the instantaneous leaf WUE (WUEi) and isotopic discrimination of carbon [...] Read more.
The current climate change is forcing growth-adapted genotypes with a higher water use efficiency (WUE). However, the evaluation of WUE is being made by different direct and indirect parameters such as the instantaneous leaf WUE (WUEi) and isotopic discrimination of carbon (δ13C) content of fruits. In the present work, WUE has been evaluated in these two ways in a wide collection of grapevine genotypes, including Tempranillo and Garnacha clones, and Tempranillo on different rootstocks (T-rootstocks). A total of 70 genotypes have been analysed in four experimental fields over two years. The parameters used to measure WUE were the bunch biomass isotopic discrimination (δ13C) and the intrinsic WUE (WUEi), defined as the ratio between net CO2 assimilation and stomatal conductance. The genotypes with the highest and lowest WUE were identified, differences between them being found to be of more than 10%. Generally, the two parameters showed coincidences in the clones with the highest and lowest WUE, suggesting that both are valuable tools to classify genotypes by their WUE in grapevine breeding programs. However, δ13C seemed to be a better indicator for determining WUE because it represents the integration over the synthesis time of the sample analysed (mainly sugars from ripening grapes), which coincides with the driest period for the crop. Moreover, the WUEi is a variable parameter in the plant and it is more dependent on the environmental conditions. The present work suggests that carbon isotopic discrimination could be an interesting parameter for the clonal selection criteria in grapevines by WUE. The main reasons were its better discrimination between clones, the fact that sampling is less time-consuming and easier to do than WUEi, and that the samples can be stored for late determinations, increasing the number of samples that can be analysed. Full article
(This article belongs to the Special Issue Current Progress in Improving Water Use Efficiency of Vineyards)
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31 pages, 2858 KiB  
Review
Irrigation Decision Support Systems (IDSS) for California’s Water–Nutrient–Energy Nexus
by Gaurav Jha, Floyid Nicolas, Radomir Schmidt, Kosana Suvočarev, Dawson Diaz, Isaya Kisekka, Kate Scow and Mallika A. Nocco
Agronomy 2022, 12(8), 1962; https://doi.org/10.3390/agronomy12081962 - 19 Aug 2022
Cited by 5 | Viewed by 5066
Abstract
California has unsustainable use of agricultural water and energy, as well as problems of severe drought, nitrate pollution and groundwater salinity. As the leading producer and exporter of agricultural produce in the United States, 5.6 percent of California’s energy is currently used for [...] Read more.
California has unsustainable use of agricultural water and energy, as well as problems of severe drought, nitrate pollution and groundwater salinity. As the leading producer and exporter of agricultural produce in the United States, 5.6 percent of California’s energy is currently used for pumping groundwater. These problems and new regulatory policies (e.g., Sustainable Groundwater Management Act, Irrigated Lands Regulatory Program) pressure growers to schedule, account and maintain records of water, energy and nutrients needed for crop and soil management. Growers require varying levels of decision support to integrate different irrigation strategies into farm operations. Decision support can come from the public or private sector, where there are many tradeoffs between cost, underlying science, user friendliness and overall challenges in farm integration. Thus, effective irrigation management requires clear definitions, decision support and guidelines for how to incorporate and evaluate the water–nutrient–energy nexus benefits of different practices and combinations of practices under shifting water governance. The California Energy Commission-sponsored Energy Product Evaluation Hub (Cal-EPE Hub) project has a mission of providing science-based evaluation of energy-saving technologies as a direct result of improved water management for irrigation in agriculture, including current and future irrigation decision support systems in California. This project incorporates end-user perceptions into evaluations of existing decision support tools in partnership with government, agricultural and private stakeholders. In this article, we review the policy context and science underlying the available irrigation decision support systems (IDSS), discuss the benefits/tradeoffs and report on their efficacy and ease of use for the most prevalent cropping systems in California. Finally, we identify research and knowledge-to-action gaps for incorporating irrigation decision support systems into new incentives and requirements for reporting water and energy consumption as well as salinity and nitrogen management in the state of California. Full article
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12 pages, 15498 KiB  
Article
Potential Roles of Three ABCB Genes in Quinclorac Resistance Identified in Echinochloa crus-galli var. zelayensis
by Yuanlin Qi, Yongli Guo, Xudong Liu, Yuan Gao, Yu Sun, Liyao Dong and Jun Li
Agronomy 2022, 12(8), 1961; https://doi.org/10.3390/agronomy12081961 - 19 Aug 2022
Viewed by 1374
Abstract
Echinochloa crus-galli var. zelayensis is a variant of E. crus-galli (L) Beauv, and it is the most pernicious weed in the east of China. Quinclorac, as synthetic auxin herbicide, could control this kind of weed effectively. In this study, two populations were [...] Read more.
Echinochloa crus-galli var. zelayensis is a variant of E. crus-galli (L) Beauv, and it is the most pernicious weed in the east of China. Quinclorac, as synthetic auxin herbicide, could control this kind of weed effectively. In this study, two populations were used to further research the mechanism of quinclorac resistance, and the EcABCB1, EcABCB4 and EcABCB19 was functionally characterized to determine their roles in quinclorac resistance. It was found that root growth of quinclorac-resistant biotype SSXB-R was less inhibited by quinclorac at 5 μM and 50 μM when compared with the susceptible biotype JNNX-S. The results show that the IAA variations in root tip of JNNX-S were significantly higher than SSXB-R at 12 h after treatment with quinclorac (50 μM) and 1-N-naphthylthalamic acid (100 μM). There are no significant differences in IAA variations of the basal part of the root between susceptible and resistant biotypes after treatment with quinclorac and 1-N-naphthylthalamic acid (NPA). The transcript level of EcABCB1 and EcABCB19 in the root of JNNX-S showed down-regulated and up-regulated after treatment with quinclorac (TWQ) at 6 h in susceptible and resistant biotypes compared with control, respectively. The transcript level for EcABCB4 in the root showed up-regulated after TWQ at 12 h only in susceptible biotypes compared with control. It was found that the IC50 to quinclorac of AtABCB4 and AtABCB19 mutants were significantly higher than the parent line Col-0. Full article
(This article belongs to the Special Issue Herbicides Toxicology and Weeds Herbicide-Resistant Mechanism)
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14 pages, 3406 KiB  
Article
Characteristics on the Spatial Distribution of Droplet Size and Velocity with Difference Adjuvant in Nozzle Spraying
by Xinpeng Li, Liping Chen, Qin Tang, Longlong Li, Wu Cheng, Peng Hu and Ruirui Zhang
Agronomy 2022, 12(8), 1960; https://doi.org/10.3390/agronomy12081960 - 19 Aug 2022
Cited by 4 | Viewed by 1788
Abstract
The spatial distribution of droplet size and velocity affects the deposition and distribution on the target. In order to investigate the influence of different adjuvant and pressures on the spatial distribution of droplet size and velocity in atomization area of different nozzles, air [...] Read more.
The spatial distribution of droplet size and velocity affects the deposition and distribution on the target. In order to investigate the influence of different adjuvant and pressures on the spatial distribution of droplet size and velocity in atomization area of different nozzles, air induction flat fan nozzle IDK120-03, multi-range flat fan nozzle LU120-03 and anti-drift flat fan nozzle AD120-03 were selected. Phase Doppler Interferometer (PDI) was used to analyze and compare the distribution of droplet size and velocity in the atomization area of three nozzles when four typical adjuvant Maisi, Maidao, Adsee AB-600 and Surun sprayed at different pressures. The results show that the volume median diameter of droplet size has no obvious change along the vertical direction of the nozzle center and increases with distance in the horizontal direction, the droplet size decreases with increasing pressure at the same position, the adjuvant all increases the droplet size (about 12%, 12%, 10% and 9% for Maisi, Maidao, Surun and Adsee AB-600, respectively), IDK120-03 nozzle droplet size is the largest and LU120-03 nozzle is the smallest in the same position. For droplet velocity distribution, droplet velocity decrease in distance along the vertical and horizontal direction, respectively, the droplet velocity increases with increasing pressure at the same position, compared with water, the droplet velocity increased by about 13%, 9%, 8%, and 4% for Maisi, Maidao, Surun, and Adsee AB-600, respectively, the velocity of AD nozzle is the largest and IDK nozzle is the smallest at the same position. The experiment can provide a basis for the selection of adjuvants and nozzles in pesticide application, and provide a data base for studying the distribution of droplets on the target. Full article
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20 pages, 2790 KiB  
Article
An Integration of Transcriptomic Data and Modular Gene Co-Expression Network Analysis Uncovers Drought Stress-Related Hub Genes in Transgenic Rice Overexpressing OsAbp57
by Muhammad-Redha Abdullah-Zawawi, Lay-Wen Tan, Zuraida Ab Rahman, Ismanizan Ismail and Zamri Zainal
Agronomy 2022, 12(8), 1959; https://doi.org/10.3390/agronomy12081959 - 19 Aug 2022
Cited by 2 | Viewed by 1831
Abstract
Auxin receptor plays a significant role in the plant auxin signalling pathway in response to abiotic stress. Recently, we found that transgenic rice overexpressing ABP57 had higher drought tolerance than the wild-type cultivar, MR219, due to the fact of its enhanced leaf photosynthetic [...] Read more.
Auxin receptor plays a significant role in the plant auxin signalling pathway in response to abiotic stress. Recently, we found that transgenic rice overexpressing ABP57 had higher drought tolerance than the wild-type cultivar, MR219, due to the fact of its enhanced leaf photosynthetic rate and yields under drought stress. We performed a microarray study on this line to investigate the underlying mechanisms contributing to the observed phenotype. After microarray data filtering, 3596 genes were subjected to modular gene co-expression network (mGCN) development using CEMiTool, an R package. We identified highly related genes in 12 modules that could act to specific responses towards drought or any of the abiotic stress types. Gene set enrichment and overrepresentation analyses for modules extracted two highly upregulated modules that are involved in drought-related biological processes such as transmembrane transport of metal ions and response to oxidative stress. Finally, 123 hub genes were identified in all modules after integrating co-expression information with physical interaction data. In addition, the interplay of significant pathways between the metabolism of chlorophyll and flavonoid and the signalling pathways of MAPK, IAA, and SA inferred the concurrent involvement of stress tolerance response. Collectively, our findings seek new future directions for breeding strategies in rice tolerant improvements. Full article
(This article belongs to the Special Issue Omics Approaches for Crop Improvement)
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13 pages, 3486 KiB  
Article
Tender Leaf Identification for Early-Spring Green Tea Based on Semi-Supervised Learning and Image Processing
by Jie Yang and Yong Chen
Agronomy 2022, 12(8), 1958; https://doi.org/10.3390/agronomy12081958 - 19 Aug 2022
Cited by 8 | Viewed by 2300
Abstract
Tea is one of the most common beverages in the world. Automated machinery that is suitable for plucking high-quality green tea is necessary for tea plantations and the identification of tender leaves is one of the key techniques. In this paper, we proposed [...] Read more.
Tea is one of the most common beverages in the world. Automated machinery that is suitable for plucking high-quality green tea is necessary for tea plantations and the identification of tender leaves is one of the key techniques. In this paper, we proposed a method that combines semi-supervised learning and image processing to identify tender leaves. Both in two-dimensional and three-dimensional space, the three R, G, and B components of tender leaves and their backgrounds were trained and tested. The gradient-descent method and the Adam algorithm were used to optimize the objective function, respectively. The results show that the average accuracy of tender leaf identification is 92.62% and the average misjudgment rate is 18.86%. Our experiments have shown that green tea tender leaves in early spring can be identified effectively using the model based on semi-supervised learning, which has strong versatility and perfect adaptability, so as to improve the problem of deep learning requiring a large number of labeled samples. Full article
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24 pages, 8099 KiB  
Article
In Vitro Regeneration of Stevia (Stevia rebaudiana Bertoni) and Evaluation of the Impacts of Growth Media Nutrients on the Biosynthesis of Steviol Glycosides (SGs)
by Asish Kumar Ghose, Siti Nor Akmar Abdullah, Muhammad Asyraf Md Hatta and Puteri Edaroyati Megat Wahab
Agronomy 2022, 12(8), 1957; https://doi.org/10.3390/agronomy12081957 - 19 Aug 2022
Cited by 5 | Viewed by 2749
Abstract
A plant tissue culture protocol from stevia was optimized for the production of planting materials and the natural sweetener, rebaudioside A. The highest survivability (88.90% ± 5.55) of explants was achieved at 15 and 30 days after culture initiation (DACI) on Murashige and [...] Read more.
A plant tissue culture protocol from stevia was optimized for the production of planting materials and the natural sweetener, rebaudioside A. The highest survivability (88.90% ± 5.55) of explants was achieved at 15 and 30 days after culture initiation (DACI) on Murashige and Skoog (MS) media by sterilization with 30% Clorox (5 min) and 10% Clorox (10 min), respectively. Supplementation of MS with 0.50 mg/L 2,4-Dichlorophenoxyacetic acid (2,4-D) and 0.10 mg/L zeatin produced 50% callus at 15 DACI while 1.50 mg/L 2,4-D and 0.10 mg/L zeatin at 30 DACI increased callus production to 76.67%. The highest shoot proliferation per callus was achieved with 10.00 mg/L 6-benzyl amino purine (BAP) in MS at 15 DACI (5.80) and 30 DACI (12.33). The longest shoots of 4.31 cm and 6.04 cm at 15 and 30 DACI, respectively, were produced using BAP (10.00 mg/L) and 1.00 mg/L naphthalene acetic acid (NAA). MS media (0.50 strength) induced 2.86 and 6.20 roots per shoot and produced 3.25 cm and 7.82 cm long roots at 15 and 30 DACI, respectively. Stevia grown on 0.25 MS accumulated the highest concentration of rebaudioside A (6.53%), which correlated with the expression level of its biosynthetic gene uridine-diphosphate-dependent (UDP)-glycosyltransferase (UGT76G1). Full article
(This article belongs to the Special Issue Medicinal Plants—Natural Sources of Bioactive Secondary Metabolites)
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16 pages, 4602 KiB  
Article
Evaluation of Bacillus velezensis Biocontrol Potential against Fusarium Fungi on Winter Wheat
by Anzhela Mikhailovna Asaturova, Natalya Andreevna Zhevnova, Natalia Sergeevna Tomashevich, Tatiana Mikhailovna Sidorova, Anna Igorevna Homyak, Valentina Mikhailovna Dubyaga, Vladimir Dmitrievich Nadykta, Artem Pavlovich Zharikov, Yuri Irodionovich Kostyukevich and Boris Sergeevich Tupertsev
Agronomy 2022, 12(8), 1956; https://doi.org/10.3390/agronomy12081956 - 19 Aug 2022
Cited by 3 | Viewed by 2259
Abstract
Fungi of the genus Fusarium are economically significant pathogens in most wheat-growing regions worldwide. The biocontrol agents Bacillus velezensis BZR 336 g and BZR 517 were tested for growth inhibition of F. graminearum BZR 4. The results demonstrated that the strains are capable [...] Read more.
Fungi of the genus Fusarium are economically significant pathogens in most wheat-growing regions worldwide. The biocontrol agents Bacillus velezensis BZR 336 g and BZR 517 were tested for growth inhibition of F. graminearum BZR 4. The results demonstrated that the strains are capable of deforming and destroying hyphae. The modified bioautography technique showed that the strains produce iturin A and surfactin, which probably explains the mechanism of pathogen inhibition. Furthermore, lipopeptides were detected and identified in two samples by the HPLC-HRMS. Compounds such as surfactin and their isomers and homologues were found in both samples. An experiment on an artificial infectious background in a climatic chamber established that the biological effectiveness of strains is close to that of chemical and biological references. Cultivation of plants with B. velezensis showed that the strains are likely to reduce the stress load. An efficacy of up to 45.0% was determined for bioagents BZR 336 g and BZR 517 in field trials, while the yield was up to 7.9 t/ha. The use of B. velezensis BZR 336 g and BZR 517 as biocontrol agents provides an environmentally friendly approach to the control of Fusarium rots on wheat, reduction of the pesticide load, and hence quality harvest. Full article
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14 pages, 3376 KiB  
Article
An R2R3-Type Transcription Factor OsMYBAS1 Regulates Seed Germination under Artificial Accelerated Aging in Transgenic Rice (Oryza sativa L.)
by Rong Wu, Yunqian Ding, Chenyong Li, Bangkui Wu, Zhongji Huang, Zhenan Li, Xiaomin Wang and Guangwu Zhao
Agronomy 2022, 12(8), 1955; https://doi.org/10.3390/agronomy12081955 - 19 Aug 2022
Cited by 2 | Viewed by 1470
Abstract
MYB-type transcription factors play an essential regulatory role in seed germination and the response to seedling establishment stress. This study isolated a rice R2R3-MYB transcription factor, OsMYBAS1, and functionally characterized its role in seed germination. There was no significant difference in the germination [...] Read more.
MYB-type transcription factors play an essential regulatory role in seed germination and the response to seedling establishment stress. This study isolated a rice R2R3-MYB transcription factor, OsMYBAS1, and functionally characterized its role in seed germination. There was no significant difference in the germination rate of each transgenic line in the standard germination test. However, compared to the germination rate of the wild type (WT) measured in the artificial accelerated aging test, the germination rates of the overexpression lines OE-OsMYBAS1-1 and OE-OsMYBAS1-2 were significantly increased by 25.0% and 21.7%, respectively. In contrast, the germination rates of the knockout mutants osmybas1-1 and osmybas1-2 were decreased by 21.7% and 33.3%, respectively. Additionally, the above data indicated that OsMYBAS1 possibly plays a positive role in rice seed germination. Moreover, the antioxidant enzyme activities of OsMYBAS1-overexpressing plants were enhanced by 38.5% to 151.0% while the superoxide dismutase (SOD) enzyme activity of osmybas1 mutants was decreased by 27.5%, and the malondialdehyde (MDA) content was increased by 24.7% on average. Interestingly, the expression of the antioxidation-related genes OsALDH3, OsAPX3, and OsCATC was enhanced in the OsMYBAS1 overexpression lines, which is consistent with the above results. Furthermore, transcriptome sequencing determined 284 differentially expressed genes (DEGs), which were mainly involved in the carbohydrate metabolic process, glycerolipid metabolism, and glycerophospholipid metabolism. Therefore, these findings provide valuable insight into the breeding of new rice varieties with high seed germination. Full article
(This article belongs to the Section Crop Breeding and Genetics)
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17 pages, 6768 KiB  
Article
Investigation of Solanum carolinense Dominance and Phytotoxic Effect in Festuca arundinacea with Special Reference to Allelochemical Identification, Analysis of Phytohormones and Antioxidant Mechanisms
by Lee-Rang Kim, Arjun Adhikari, Yosep Kang, Ho-Jun Gam, Sang-Mo Kang, Ki-Yong Kim and In-Jung Lee
Agronomy 2022, 12(8), 1954; https://doi.org/10.3390/agronomy12081954 - 19 Aug 2022
Cited by 6 | Viewed by 1659
Abstract
Exposure to invasive weeds in pasturelands may result in significant losses and toxicity in forage crops. These species may also contain a compound that may be toxic as well as beneficial depending upon the effect induced. The Ministry of Environment of the Republic [...] Read more.
Exposure to invasive weeds in pasturelands may result in significant losses and toxicity in forage crops. These species may also contain a compound that may be toxic as well as beneficial depending upon the effect induced. The Ministry of Environment of the Republic of Korea has now recognized Solanum carolinense (Horsenettle)—an invasive weed species—as a potential threat to forage crops in pasturelands and to the entire agro-ecosystem. As a forage crop, Festuca arundinacea (Tall fescue) is one of the major economical crops and diets of livestock; in this study, the competition patterns of Solanum carolinense and Festuca arundinacea were examined with respect to their seeding ratios and growth periods. In addition, an extract from the root of Solanum carolinense (SCE) was prepared and treated at 2500 ppm and 5000 ppm in a Festuca arundinacea plant to observe its effect. The experimental results showed that as the growth period of the Horsenettle and the SCE treatment increased, the germination rate, plant height, root length, fresh weight, and dry weight of the tall fescue were significantly decreased. Moreover, the SCE treatment significantly increased the quantities of reactive oxygen species (O2 and H2O2), antioxidants (Catalase and Peroxidase), and endogenous phytohormones (Abscisic acid and Salicylic acid), and simultaneously decreased the superoxide dismutase content in the tall fescue shoots. Furthermore, we identified several glycoalkaloids from the SCE extract, among which Solanidan-3-ol, (3β,5α)’ possessed a higher number (52%). Based on these results, we predicted that the Solanidan-3-ol, (3β,5α)’ present in horsenettle has a major role in imposing phytotoxicity on agricultural crops. The glycoalkaloids in the Solanum species have been reported to possess both phytotoxic and therapeutic uses. Based on this concept, we believe that the compound available in Solanum carolinense could be used in developing crop protection or medicinal products through broader research. Conversely, our findings also showed the probable risk of horsenettle to the agro-ecosystem, especially in terms of forage production. Full article
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12 pages, 321 KiB  
Article
Nitrogen Use Efficiency and Partitioning of Dairy Heifers Grazing Perennial Ryegrass (Lolium perenne L.) or Pasture Brome (Bromus valdivianus Phil.) Swards during Spring
by Ignacio E. Beltran, Daniel Tellez, Jaime Cabanilla, Oscar Balocchi, Rodrigo Arias and Juan Pablo Keim
Agronomy 2022, 12(8), 1953; https://doi.org/10.3390/agronomy12081953 - 18 Aug 2022
Viewed by 1637
Abstract
The aim of the study was to evaluate the effect of grazing Lolium perenne (Lp) and Bromus valdivianus (Bv) on the average daily weight gain (ADG) and nitrogen use efficiency (NUE) of Holstein Friesian heifers. Thirty heifers strip-grazed two pasture treatments (Lp and [...] Read more.
The aim of the study was to evaluate the effect of grazing Lolium perenne (Lp) and Bromus valdivianus (Bv) on the average daily weight gain (ADG) and nitrogen use efficiency (NUE) of Holstein Friesian heifers. Thirty heifers strip-grazed two pasture treatments (Lp and Bv) under a randomized complete block design (n = 3). Nutrient concentration and pasture intake were determined. Urine samples were taken, and the total volume of urine and microbial growth were estimated. Retained nitrogen (N), N intake, N excreted in feces and urine and the nitrogen use efficiency (NUE) were calculated. Lolium perenne showed greater WSC and ME but lower NDF than Bv, whereas crude and soluble protein were unaffected. There were no effects of species on ADG or feed conversion, and DMI was not affected by grass species, or the synthesis of microbial protein and purine derivatives. Ammonia in the rumen, urinary N and total N excreted were greater for heifers grazing Bv. In conclusion, the consumption of forage species did not alter the ADG or NUE of grazing heifers, but N partitioning was modified for heifers grazing Bv, due to the lower WSC/CP ratio compared with Lp. Full article
(This article belongs to the Special Issue Assessing Sustainability of Ruminant Livestock Forage-Based Systems)
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