Research

Jump to: Review

10 pages, 2348 KiB

Open AccessArticle

In Vitro Propagation of Peumus boldus Mol, a Woody Medicinal Plant Endemic to the Sclerophyllous Forest of Central Chile

by Francesca Guerra, Loreto Badilla, Ricardo Cautín and Mónica Castro

Horticulturae 2023, 9(9), 1032; https://doi.org/10.3390/horticulturae9091032 - 14 Sep 2023

Viewed by 1324

Abstract

Peumus boldus Mol (P. boldus), a Chilean endemic tree species occurring in sclerophyllous or evergreen forests, has historically played a significant role in indigenous ancestral medicine. Recently, P. boldus has garnered renewed attention, spurred by the growing interest in its leaves [...] Read more.

Peumus boldus Mol (P. boldus), a Chilean endemic tree species occurring in sclerophyllous or evergreen forests, has historically played a significant role in indigenous ancestral medicine. Recently, P. boldus has garnered renewed attention, spurred by the growing interest in its leaves and bark. These parts contain a wealth of bioactive agents, including alkaloids, flavonoids, essential oils, and potent antioxidant properties attributed to their high phenolic compound content. However, the species’ regeneration within its native habitat has been hindered by a confluence of factors such as climate change, agricultural activities, and shifts in land use. Coupled with the seeds’ low germination rate and protracted emergence period, the necessity to develop large-scale propagation methods to bolster P. boldus population numbers has become increasingly evident. Furthermore, the widespread use of P. boldus for medicinal purposes renders it vulnerable to overexploitation, thereby underscoring the need for a comprehensive mass propagation protocol to support conservation efforts. Thus, the main objective of this study was to formulate an in vitro protocol for mass regeneration of P. boldus. The explants excised from nodal sections demonstrated an average survival rate of 74%, while the application of 6-benzylaminopurine (4.44 μM) yielded an average shoot length of 5.9 cm. In vitro shoot rooting achieved a success rate of 80% using perlite supplemented with indole-3-butyric acid (9.84 μM). During the acclimation phase, in vitro rooted plants displayed a remarkable 100% survival rate at the 30-day mark after being transplanted into a substrate consisting of perlite and peat in a (1:1 v/v) ratio. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

16 pages, 2695 KiB

Open AccessArticle

The Effects of Different Auxin–Cytokinin Combinations on Morphogenesis of Fritillaria meleagris Using Bulb Scale Sections In Vitro

by Marija Marković, Milana Trifunović-Momčilov, Olga Radulović, Danijela M. Paunović, Dragana D. Antonić Reljin, Branka Uzelac and Angelina Subotić

Horticulturae 2023, 9(8), 910; https://doi.org/10.3390/horticulturae9080910 - 10 Aug 2023

Cited by 2 | Viewed by 1159

Abstract

Fritillaria meleagris is a horticulturally and medicinally valuable bulbous plant that requires a period of low temperatures for proper growth and flowering. Since conventional methods of propagation are ineffective and very slow, tissue culture techniques offer an integrated approach to mass production of [...] Read more.

Fritillaria meleagris is a horticulturally and medicinally valuable bulbous plant that requires a period of low temperatures for proper growth and flowering. Since conventional methods of propagation are ineffective and very slow, tissue culture techniques offer an integrated approach to mass production of this valuable geophyte. In this study, we investigated the effects of various auxin–cytokinin combinations on different morphogenetic pathways in bulb scale culture. Bulbs obtained in vitro were cut longitudinally, and bulb scales were cultured for four weeks at 7 °C on MS medium supplemented with 6-benzylaminopurine (BAP) in combination with 2,4-dichlorophenoxyacetic acid (2,4-D) or α-naphthaleneacetic acid (NAA) at different concentrations in order to investigate the influence of plant growth regulators (PGRs) on different morphogenetic responses. Regeneration percentage, number of shoots per explant, shoot length, number of bulbs and number of somatic embryos were monitored weekly. After chilling, bulb scales were transferred to 24 °C, and all parameters were recorded again. Low PGR concentrations were very effective for shoot multiplication, yielding up to 5.5 shoots per explant. 2,4-D (at 2 mg/L) in combination with low BAP (0.25 mg/L) produced the highest number of bulbs (11.00 ± 0.00), while PGR-free medium was extremely effective in somatic embryo formation (13.50 ± 2.90). Detached somatic embryos and bulblets continued to grow and develop on fresh PGR-free medium. We present data demonstrating that low auxin–cytokinin concentrations and PGR-free medium provide an effective method for a combined morphogenetic pathway in F. meleagris that is suitable for large-scale propagation. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

18 pages, 4279 KiB

Open AccessArticle

Methyl Jasmonate Elicitation for In Vitro Lycorine Accumulation in Three Zephyranthes Species and Comparative Analysis of Tissue-Cultured and Field Grown Plants

by Rukaya Syeed, Abdul Mujib, Yaser Hassan Dewir, Moien Qadir Malik, Yashika Bansal, Bushra Ejaz, Jyoti Mamgain, Mansor Hakiman and Ali Alsughayyir

Horticulturae 2023, 9(7), 832; https://doi.org/10.3390/horticulturae9070832 - 21 Jul 2023

Cited by 2 | Viewed by 1478

Abstract

Lycorine is an important Amaryllidaceae alkaloid showing anti-cancerous activity on numerous cell lines; and it also demonstrates antiviral activity against several viruses including SARS-CoV-2 responsible for COVID-19. The in vitro cultivation of plant parts is a good alternative for elicitor mediated secondary metabolite [...] Read more.

Lycorine is an important Amaryllidaceae alkaloid showing anti-cancerous activity on numerous cell lines; and it also demonstrates antiviral activity against several viruses including SARS-CoV-2 responsible for COVID-19. The in vitro cultivation of plant parts is a good alternative for elicitor mediated secondary metabolite synthesis, mass propagation, and cloning of elite genotypes. In this study, the quantification of lycorine from Zephyranthes candida, Zephyranthes grandiflora, and Zephyranthes citrina was evaluated, and the influence of methyl jasmonate (MJ) treatments on accumulation of lycorine yield was observed in the in vitro cultivated tissues. The influence of methyl jasmonate (MJ) on accumulation of lycorine was investigated for the first time in in vitro regenerated bulb, leaf, and root tissues of Zephyranthues. The efficient in vitro shoot regeneration was achieved in Z. candida (73.9%), Z. grandiflora (85.5%), and Z. citrina (76.5%) on Murashige and Skoog (MS) medium amended with 2.0 mg·L⁻¹ Naphthalene acetic acid + 0.5 mg·L⁻¹ Benzylaminopurine. The regenerants had the highest i.e., 7.46 mean numbers of bulblets per shoot. The best root induction (80.66%) was achieved on 2.0 mg/L Indole butyric acid (IBA). The lycorine content was quantified through High performance thin layer chromatography (HPTLC) in three field grown Zephyranthes species, was highest in Z. candida (1.93 µg g⁻¹ dry wt.), followed by Z. grandiflora (1.87 µg g⁻¹ dry wt.) and Z. citrina (1.62 µg g⁻¹ dry wt.). The yield of lycorine was observed in this order i.e., bulb > leaf > root. The regenerated plants were supplemented with MJ and maximum lycorine yield was noted at 100 µM in bulb tissues of Z. candida (2.74 µg g⁻¹ dry wt.) with an increase in percentage of 39.08. The enhancement could be due to MJ-induced stress as the biochemical attributes and anti-oxidant enzyme activity were high with elevated level of MJ. This enrichment may auger commercial manufacturing and utilization of lycorine in future. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

13 pages, 4177 KiB

Open AccessArticle

Production of Tetraploid Plants from Cotyledons of Diploid Melia volkensii Gürke

by Constantin Dushimimana, Katrijn Van Laere, Titus Magomere, Guy Smagghe and Stefaan P. O. Werbrouck

Horticulturae 2023, 9(7), 791; https://doi.org/10.3390/horticulturae9070791 - 11 Jul 2023

Cited by 1 | Viewed by 1852

Abstract

Polyploidy was induced in Melia volkensii (Mukau), a valuable native tree from the semi-arid regions of East Africa. Cotyledons of diploid M. volkensii (2n = 2x = 28) were treated with oryzalin for 0 (control), 1, 2, or 3 h with or without [...] Read more.

Polyploidy was induced in Melia volkensii (Mukau), a valuable native tree from the semi-arid regions of East Africa. Cotyledons of diploid M. volkensii (2n = 2x = 28) were treated with oryzalin for 0 (control), 1, 2, or 3 h with or without pretreatment with 1.1 µM thidiazuron. Cotyledons treated with 10 mg·L⁻¹ oryzalin for three hours yielded 40% tetraploids. Pretreatment of cotyledons with thidiazuron for 18 days followed by treatment with oryzalin increased tetraploid plant production to 52.5%, but this also yielded more mixoploids. Compared to diploid M. volkensii, the tetraploid in vitro and young potted plants were compacter, with thicker stems, wider leaves, and a low density of longer and wider stomata. In the coming years, tetraploid M. volkensii plants will be observed in field trials and serve as a basis for further breeding efforts. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

20 pages, 1631 KiB

Open AccessArticle

Non-Enzymatic and Enzymatic Antioxidant Responses of Hypericum perforatum L. Hairy Roots upon Photooxidative Stress

by Oliver Tusevski and Sonja Gadzovska Simic

Horticulturae 2023, 9(5), 581; https://doi.org/10.3390/horticulturae9050581 - 13 May 2023

Cited by 2 | Viewed by 1170

Abstract

The aim of this study was to evaluate the non-enzymatic and enzymatic antioxidant response of fifteen Hypericum perforatum L. dark-grown (HR1 A-HR1 O) and photoperiod-exposed (HR2 A-HR2 O) hairy root clones. Dark-grown HR1 clones were characterized with high biomass accumulation and up-regulated phenylpropanoid [...] Read more.

The aim of this study was to evaluate the non-enzymatic and enzymatic antioxidant response of fifteen Hypericum perforatum L. dark-grown (HR1 A-HR1 O) and photoperiod-exposed (HR2 A-HR2 O) hairy root clones. Dark-grown HR1 clones were characterized with high biomass accumulation and up-regulated phenylpropanoid metabolism through phenylalanine ammonia lyase (PAL)-mediated production of flavonoids, flavan-3-ols and anthocyanins. These groups of phenolics showed superior hydrogen-donating capability and significantly contributed to the antioxidant capacity of dark-grown HR1 clones. Photoperiod-exposed HR2 clones showed green coloration with shoot regenerative potential and reduced biomass accumulation. Photoperiod exposition improved the production of hypericins, as well as ferrous chelating properties and lipid peroxidation inhibition activity in HR2 cultures. Furthermore, HR2 clones were represented with enhanced activity of antioxidant enzymes (guaiacol peroxidase, catalase and superoxide dismutase) that resulted in suppression of oxidative stress markers (hydrogen peroxide, superoxide anion and malondialdehyde). These observations revealed the involvement of an efficient antioxidant defense system in the adaptive response of HR to photooxidative stress. Altogether, photoperiod-exposed H. perforatum HR2 clones were considered as a promising alternative for further scale-up production of naphthodianthrones that could be used in the pharmaceutical industry. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Graphical abstract

18 pages, 3291 KiB

Open AccessArticle

In Vitro Shoot Multiplication and Regeneration of the Recalcitrant Rocket (Eruca sativa Mill.) Variety Domaća Rukola

by Nevena Banjac, Dijana Krstić-Milošević, Tatjana Mijalković, Mirjana Petrović, Tatjana Ćosić, Mariana Stanišić and Branka Vinterhalter

Horticulturae 2023, 9(5), 533; https://doi.org/10.3390/horticulturae9050533 - 24 Apr 2023

Cited by 2 | Viewed by 1302

Abstract

Eruca sativa is known in traditional medicine for its therapeutic effects, while young plants are used as a salad or green food. Recently, the consumption of rocket has increased considerably, so it has become very important for breeders. Plant tissue culture provides a [...] Read more.

Eruca sativa is known in traditional medicine for its therapeutic effects, while young plants are used as a salad or green food. Recently, the consumption of rocket has increased considerably, so it has become very important for breeders. Plant tissue culture provides a platform to overcome the problems in improving this species. In the present study, an efficient protocol for in vitro shoot regeneration and propagation of recalcitrant rocket variety Domaća rukola was studied. Murashige and Skoog (MS, 1962) medium containing 0.1 mg L⁻¹ BA and frequent subculture over a period of three weeks proved to be optimal for shoot multiplication with a multiplication index of over 3 and only 8.72% of hyperhydrated shoots without necrosis. Different concentrations of 2,4-D, BA, or TDZ in combination with NAA, with or without the presence of AgNO₃, were tested for de novo shoot organogenesis (DNSO) from seedling explants. The hypocotyl explants cultured on MS with a combination of TDZ1.0+NAA0.1+AgNO₃ 5.0 mg L⁻¹ regenerated viable shoots with the highest rate (25.38%) and an average number of 2.18 shoots per regenerating explant. Somatic embryogenesis from immature zygotic embryos proved to be the best way to regenerate a recalcitrant rocket cultivar. The highest embryogenic efficiency was achieved in explants cultured on MS medium containing 1.0 mg L⁻¹ 2,4-D with a frequency of 76.64% and 5.13 mean number of regenerated somatic embryos per explant, which were further converted into normal plants. Additionally, in vitro-produced rocket shoots could serve as a possible promising source for the production of flavonoid kaempferol with proven antioxidant properties. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

11 pages, 2802 KiB

Open AccessArticle

In Vitro Micropropagation of Commercial Ginseng Cultivars (Panax ginseng Meyer) via Somatic Embryogenesis Compared to Traditional Seed Production

by Jung-Woo Lee, Nayeong Kwon, Jang-Uk Kim, Kyong-Hwan Bang, Sung Min Jung, Sung Woo Lee, Dong-Hwi Kim, Young-Chang Kim, Ick-Hyun Jo and Young-Doo Park

Horticulturae 2023, 9(4), 435; https://doi.org/10.3390/horticulturae9040435 - 27 Mar 2023

Cited by 1 | Viewed by 1784

Abstract

Panax ginseng Meyer is an important medicinal crop; however, most ginseng farmers cultivate native species that are not genetically fixed. Although several cultivars have been developed in Korea, distribution to farmers remains insufficient given their low propagation characteristics. This study compared the efficiency [...] Read more.

Panax ginseng Meyer is an important medicinal crop; however, most ginseng farmers cultivate native species that are not genetically fixed. Although several cultivars have been developed in Korea, distribution to farmers remains insufficient given their low propagation characteristics. This study compared the efficiency of seed production and micropropagation via somatic embryogenesis. Seeds were collected from cultivars, and zygotic embryo-derived explants were inoculated and cultured in a series of media for micropropagation. Seed production and characteristics of commercial cultivars were evaluated. The number of seeds from a 4-year-old individual cultivar was 23.1–58.8, and seed characteristics varied with cultivars. The genotype had a notable effect on somatic embryogenesis and plant regeneration. The number of somatic embryos and shoots obtained from a single seed of cultivars was 71.3–100.2 and 50.7–61.3, respectively. The number of in vitro grown roots (IGRs) per a single seed was 37.1–41.1 in one year. IGRs were successfully acclimatized and sprouted normally in the field. Flow cytometry analysis suggested that micropropagated plants had no ploidy variations. The results demonstrated the utility of somatic embryogenesis in the in vitro micropropagation of P. ginseng cultivars. Our findings can enhance the distribution of cultivars among farmers in the future. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

14 pages, 1399 KiB

Open AccessArticle

Chemical Characterization, Antioxidant Activity, and Cytotoxity of Wild-Growing and In Vitro Cultivated Rindera umbellata (Waldst. and Kit.) Bunge

by Slađana Todorović, Marija Perić, Biljana Nikolić, Boris Mandić, Stefana Cvetković, Milica Bogdanović and Suzana Živković

Horticulturae 2023, 9(3), 381; https://doi.org/10.3390/horticulturae9030381 - 15 Mar 2023

Viewed by 1218

Abstract

The aim of this study was to comparatively analyze chemical composition and biological activity of wild- and in vitro grown Rindera umbellata. Explants were cultivated on 0.003–0.3 M sucrose, fructose, or glucose. HPLC-DAD for quantifying rosmarinic (RA) and lithospermic B (LAB) acids [...] Read more.

The aim of this study was to comparatively analyze chemical composition and biological activity of wild- and in vitro grown Rindera umbellata. Explants were cultivated on 0.003–0.3 M sucrose, fructose, or glucose. HPLC-DAD for quantifying rosmarinic (RA) and lithospermic B (LAB) acids and GC-MS/FID for qualitative pyrrolizidine alkaloids (PAs) detection were used. Antioxidant activity (DPPH and ABTS assays) and cytotoxicity (MTT test) were monitored. Identified PAs were 7-angeloyl heliotridane, lindelofine, 7-angeloyl heliotridine, 7-angeloyl-9-(+)-trachelanthylheliotridine, punctanecine, and heliosupine, with higher variability reported in wild-growing samples. Total phenolic contents (TPCs) were comparable in wild-growing and in vitro samples, but total flavonoid (TFC) and RA levels were multifold higher in in vitro samples. Notably, high concentration of LAB was detected in wild-growing roots. Amounts of 0.3 M and 0.1 M of sucrose were optimal for TFC and RA production, while maximal antioxidant activity was monitored in plants grown on 0.3 M sucrose. The MTT test indicated colorectal HT-29 as more sensitive than A549 lung adenocarcinoma and normal MRC-5 cells, showing selective sensitivity to wild-growing and 0.3 M sucrose samples. In conclusion, PAs in vitro, as well as TPC, TFC, RA, and LAB in both growing conditions were detected for the first time in R. umbellata. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Graphical abstract

21 pages, 4043 KiB

Open AccessArticle

Large-Scale In Vitro Propagation and Ex Vitro Adaptation of the Endangered Medicinal Plant Eryngium maritimum L.

by Ieva Mežaka, Dace Kļaviņa, Laura Kaļāne and Arta Kronberga

Horticulturae 2023, 9(2), 271; https://doi.org/10.3390/horticulturae9020271 - 17 Feb 2023

Cited by 5 | Viewed by 1999

Abstract

The endangered medicinal plant Eryngium maritimum L. faces significant natural and anthropogenic threats. Therefore, in vitro propagation is recommended for both conservation and commercial purposes. The aim of the study was to develop a series of protocols for seed disinfection, in vitro multiplication [...] Read more.

The endangered medicinal plant Eryngium maritimum L. faces significant natural and anthropogenic threats. Therefore, in vitro propagation is recommended for both conservation and commercial purposes. The aim of the study was to develop a series of protocols for seed disinfection, in vitro multiplication and rooting, and ex vitro and field adaptation. For explant disinfection, the length and temperature of three consecutive disinfectants were investigated. Macrosalt modifications of MS medium and plant growth regulator addition to media effect on axillary bud propagation rate and rooting was studied. Survival and leaf growth during ex vitro and field adaptation in response to potting media, pot cell diameter, and light spectrum were tested. Seeds treated with diluted detergent at 40 °C for 180 min, followed by 0.01% KMnO₄ for 3 h and commercial bleach for 11 min, achieved a lower rate of contamination and high germination rate. Axillary bud proliferation and rooting were enhanced by reducing nitrogen content in media and adding plant growth regulators. Potting media and pot size affect survival and growth ex vitro. Timely transplantation to field conditions before overwintering increases plantlet survival. In the present work, a suitable foundation is laid to scaleup the production of E. maritimum by micropropagation. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

12 pages, 2572 KiB

Open AccessArticle

Early Performance of Recently Released Rootstocks with Grapefruit, Navel Orange, and Mandarin Scions under Endemic Huanglongbing Conditions in Florida

by J. Martin Zapien-Macias, Rhuanito Soranz Ferrarezi, Peter D. Spyke, William S. Castle, Frederick G. Gmitter, Jr., Jude W. Grosser and Lorenzo Rossi

Horticulturae 2022, 8(11), 1027; https://doi.org/10.3390/horticulturae8111027 - 03 Nov 2022

Cited by 3 | Viewed by 1908

Abstract

Huanglongbing (HLB), which is believed to be caused by the phloem-restricted bacterium Candidatus Liberibacter asiaticus (CLas), has decimated Florida’s citrus production. Grapefruit production has declined 75%, mandarin 78%, and sweet orange 52% due to the high sensitivity of commercial scions and [...] Read more.

Huanglongbing (HLB), which is believed to be caused by the phloem-restricted bacterium Candidatus Liberibacter asiaticus (CLas), has decimated Florida’s citrus production. Grapefruit production has declined 75%, mandarin 78%, and sweet orange 52% due to the high sensitivity of commercial scions and rootstocks to the disease. New combinations of scions and hybrid rootstocks may provide better performance than current commercial selections for Florida’s fresh citrus production, particularly in the Indian River District. The objective of this study was to evaluate and compare University of Florida rootstocks and other recently released rootstocks grafted with grapefruit, navel orange, and mandarin scions by measuring tree growth and HLB tolerance. Three independent large-scale field trials were established in September 2019 in Fort Pierce, FL, USA. Trial 1 (T1) included 36 rootstocks with ‘Ray Ruby’ grapefruit as the scion; Trials 2 and 3 (T2 and T3, respectively) included 30 rootstocks with ‘Glenn’ navel orange F-56-11 and ‘UF-950’ mandarin as the scion, respectively. Tree canopy volume, trunk diameter, CLas titer, HLB severity index, and leaf nutrient concentrations were evaluated during 2020 and 2021. Significant differences among rootstock-scion combinations were found in each trial for most of the assessed traits. In T2, UFR-15 consistently developed the largest ‘Ray Ruby’ grapefruit trees during both years. In T3, ‘Glenn’ navel orange F-56-11 trees were larger on C-22, and US-802. Similarly, US-802 and US-942 generated the largest ‘UF-950’ mandarin trees. Overall, trees had optimum levels of macro- and micronutrients except for calcium. CLas infection and HLB visual index varied among scion-rootstock combinations, especially during the first year of growth when intensive flushing was produced. Generally, trees grew vigorously with WGFT+50-7 and Willits inducing the lowest HLB symptoms in all evaluations. Production and fruit quality need to be evaluated to determine the suitability of potential scion-rootstock combinations that can confer consistent economical and biological advantages under the current HLB scenario in the Indian River District. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

14 pages, 3335 KiB

Open AccessArticle

Potato Aeroponics: Effects of Cultivar and Plant Origin on Minituber Production

by Zoran Broćić, Jasmina Oljača, Danijel Pantelić, Jelena Rudić and Ivana Momčilović

Horticulturae 2022, 8(10), 915; https://doi.org/10.3390/horticulturae8100915 - 06 Oct 2022

Cited by 6 | Viewed by 5689

Abstract

Aeroponics is a modern and soilless technology that is used for the efficient production of pre-basic seed potatoes, namely minitubers. This study aimed to evaluate the effects of the cultivar and type of planting material on the production of minitubers in the aeroponic [...] Read more.

Aeroponics is a modern and soilless technology that is used for the efficient production of pre-basic seed potatoes, namely minitubers. This study aimed to evaluate the effects of the cultivar and type of planting material on the production of minitubers in the aeroponic facility in Guča, Serbia, at short, 7-day harvest intervals. Although aeroponic cultivation prolonged the vegetative cycle in all five investigated cultivars, the dynamics of minituber formation varied between genotypes. Two early maturing cultivars, Cleopatra and Sinora, quickly completed the vegetative cycle and formed a small number of minitubers, while the medium-late to late cultivars, Kennebec and Agria, steadily tuberized during the entire cultivation period in the aeroponic facility. The type of planting material affected the dynamics of minituber formation in three investigated cultivars. Sinora, Cleopatra, and Désirée’s plants of in vitro origin reached the final number of minitubers and the vines started senescing much earlier than plants of minituber origin. Kennebec and Agria plants of in vitro origin produced the largest number of minitubers (53.8–54.5) and showed the highest yield (9.8–10.5 kg m⁻²) during the cultivation period, while the heaviest minitubers were formed by Sinora plants of minituber origin (15.48 g). In addition, the temperature during pre-harvest periods significantly affected the number of tubers at harvests in Kennebec and Agria, and minituber mass in Désirée. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

Review

Jump to: Research

22 pages, 1463 KiB

Open AccessReview

Somatic Embryogenesis in Spinach—A Review

by Snežana Zdravković-Korać, Maja Belić, Dušica Ćalić and Jelena Milojević

Horticulturae 2023, 9(9), 1048; https://doi.org/10.3390/horticulturae9091048 - 19 Sep 2023

Cited by 1 | Viewed by 1074

Abstract

A spinach-supplemented diet exerts numerous health benefits, but high levels of oxalic acid and nitrate can cause medical problems, so their levels should be reduced, while the levels of vitamins and phytochemicals could be further increased by breeding. Conventional spinach breeding is limited [...] Read more.

A spinach-supplemented diet exerts numerous health benefits, but high levels of oxalic acid and nitrate can cause medical problems, so their levels should be reduced, while the levels of vitamins and phytochemicals could be further increased by breeding. Conventional spinach breeding is limited by the very complex sex determination. However, these limitations could be circumvented in synergy with a biotechnological approach. Accordingly, tissue culture techniques allow rapid and efficient clonal propagation of selected valuable genotypes, and somatic embryogenesis has been recognized as a superior process for clonal propagation because somatic embryos resemble zygotic embryos and therefore can spontaneously develop into complete plants. Since spinach has been considered recalcitrant to in vitro regeneration for decades, a deeper insight into the mechanisms underlying somatic embryogenesis is important for a better understanding and further improvement of the efficiency of this process. In this review, a comprehensive overview of the major factors affecting somatic embryogenesis in spinach is presented and discussed, with particular emphasis on the synergistic effects of α-naphthaleneacetic acid, gibberellic acid, light, and the intrinsic predisposition of individual seedlings to somatic embryogenesis, as well as the expression of genes encoding key enzymes involved in the maintenance of gibberellin homeostasis and the levels of endogenous gibberellins. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

26 pages, 6527 KiB

Open AccessReview

In Vitro Growth and Regeneration of Brassica oleracea var. gongylodes: A Decade of Research

by Tatjana Ćosić, Martin Raspor, Václav Motyka, Aleksandar Cingel and Slavica Ninković

Horticulturae 2023, 9(6), 674; https://doi.org/10.3390/horticulturae9060674 - 06 Jun 2023

Viewed by 1258

Abstract

Kohlrabi (Brassica oleracea var. gongylodes) is a vegetable cultivated for its edible stem tuber. Although valued for its nutritional properties and tolerance to abiotic stress, kohlrabi is one of the least studied brassicas. In this review, we summarize the results of [...] Read more.

Kohlrabi (Brassica oleracea var. gongylodes) is a vegetable cultivated for its edible stem tuber. Although valued for its nutritional properties and tolerance to abiotic stress, kohlrabi is one of the least studied brassicas. In this review, we summarize the results of our decade-long research on in vitro morphogenesis of kohlrabi, starting from 2013. Protocols for efficient in vitro regeneration with minimal requirements for external application of plant growth regulators (PGRs) have been developed, both by somatic embryogenesis (SE) and by de novo shoot organogenesis (DNSO). Efficient regeneration by direct SE was achieved using immature zygotic embryos as explants incubated on PGR-free media, and the production process was maintained in culture thanks to highly efficient secondary SE. Conversely, efficient regeneration by indirect DNSO was achieved using entire seedlings as explants and adding only cytokinin (CK) without the need for exogenous auxin. Comprehensive phytohormone analyses revealed that different exogenously applied CKs differentially affected the composition of endogenous phytohormones and induced changes in the expression of cell cycle-related genes and other genes involved in the organogenic response. The addition of high sucrose concentrations to the nutrient media failed to induce the formation of stem tubers in in vitro culture, but revealed a complex interaction with exogenously applied CKs, interfering with both the endogenous phytohormonome and the expression of organogenesis-related genes. Our work has provided substantial biotechnological advances in the field of in vitro regeneration of kohlrabi, as well as in understanding the underlying phytohormonal regulation. The review aims to introduce kohlrabi to the scientific community as a model system for both basic and applied research, while we continue seeking answers to the outstanding questions and trying to pave the way for the development of more resistant varieties. Full article

(This article belongs to the Special Issue A New Decade in the Propagation of Horticultural and Medicinal Plants)

► Show Figures

Figure 1

Journal Menu

Journal Browser

A New Decade in the Propagation of Horticultural and Medicinal Plants

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Published Papers (13 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI