Combinations Of Plant Growth Regulators Research Articles

An Efficient Method for the Propagation of Bougainvillea glabra ‘New River’ (Nyctaginaceae) from In Vitro Stem Segments

Bougainvillea, an evergreen climbing shrub of the Nyctaginaceae family, holds significant ornamental, economic, and medicinal value. Bougainvillea glabra ‘New River’ is widely used in landscapes due to its strong adaptability to the environment, abundance of flowers, and frequent flowering. Traditionally, Bougainvillea glabra ‘New River’ cultivation has relied on methods such as cuttings or grafting, with limited research on in vitro tissue culture propagation. This study aimed to optimize the tissue culture system, exploring a combination of plant growth regulators (PGRs) for Bougainvillea regeneration from in vitro stem segments. The Murashige and Skoog (MS) medium supplemented with indole-3-butyric acid (IBA), 6-benzylaminopurine (6-BA), and 1-naphthlcetic acid (NAA) was employed. The optimal sterilization of Bougainvillea stem segments involved a 30 s treatment with 75% alcohol and 10 min with 1% NaClO. The synergistic effect of 0.1 mg·L−1 of NAA and 2.5 mg·L−1 of 6-BA maximized the shoot sprouting frequency, while 2.5 mg·L−1 of 6-BA and 0.1 mg·L−1 of NAA produced the maximum shoots. Furthermore, 1.5 mg·L−1 of IBA and 0.1 mg·L−1 of NAA induced the highest rooting levels. This work demonstrates the successful adaptation of a greenhouse environment to efficiently regenerate plants in vitro from stem segments. This approach allows for the mass production of Bougainvillea glabra ‘New River’.

Effect of Different Plant Growth Regulators on In-vitro Micropropagation of Banana Cultivar Grand Naine (Musa spp.)

Banana (Musa sapientum) is one of the most important fruit crop cultivated in India. It is widely grown in more than 150 countries, producing on an average of 105 million tons of fruit per annum. Grand naine Banana variety is the most commonly cultivated banana with high yielding plantain. This variety mainly grown in the region of Uttar Pradesh state. Present study mainly focuses on the in-vitro micropropagation method which is described for banana cv. Grand naine. For this study, healthy sword suckers of three months old banana plantlets was used as explants. The explants was sterilized thoroughly and cultured on MS (Murashige and Skoog) media supplemented with the different concentration and combination of auxin and cytokinin like BAP, IAA and NAA which were used for the optimization of best plant growth regulator combination for multiple shoot generation and shoot growth. Among all the tested cytokinin 5 mg/l BAP along with 1mg/l IAA in medium concentration performed well and produced healthy shoots further at higher concentration of all tested cytokinin showed declining effect within the growth parameters. For the rooting purpose, MS media was supplemented with different levels of IBA, IAA and NAA. Results indicated that rooting was highly promoted in the medium supplemented with 0.5 mg/L IAA + 1.5 mg/L IBA.

Effect of Plant Growth Regulators on Nutrient and Quality Changes in Zingiber officinale Rosc

Ginger is one of the oldest and renowned commercial spices well known for its medicinal and pharmaceutical value. Land degradation, availability of the quality rhizomes and diseases are some of the challenges faced in the ginger production. Since the productivity of a plant is influenced by a complex physiological process controlled by plant growth hormone balancing systems, the application of the growth regulators can have positive effect. Manipulating the PGR combinations and concentrations can lead to better quality and productivity in ginger. Hence, an experiment was conducted to study the effect of different plant growth regulators (PGRs) on nutrient and quality parameters in the ginger variety IISR Varada. Foliar spray of PGRs with 6-benzyl adenine purine (6-BAP), cycocel (Chlormequat chloride), gibberellic acid (GA) and paclobutrazol (PBZ) with five concentrations viz., 50ppm, 100ppm, 150ppm and 200ppm were applied 4th month after planting and water spray treated as control. Nutrients composition and biochemical components were observed on 5th month after planting and oleoresin was observed in the rhizomes after harvest. The results of pooled data over two years revealed that GA at 100 ppm recorded maximum nitrogen and chlorophyll content in leaves, potassium and protein in rhizomes. Regarding the oil content, maximum was noticed in treatment 100ppm Paclobutrazol followed by GA 100ppm.

An Efficient Agrobacterium-Mediated Genetic Transformation System for Gene Editing in Strawberry (Fragaria × ananassa).

The octoploid-cultivated strawberry variety Benihope (Fragaria × ananassa Duch cv. Benihope) is an important commercial plant. It is highly susceptible to different diseases, which ultimately leads to a reduction in yield. Gene-editing methods, such as CRISPR/Cas9, demonstrate potential for improving disease resistance in the strawberry cv. Benihope. Establishing a plant regeneration system suitable for CRISPR/Cas9 gene editing is crucial for obtaining transgenic plants on a large scale. This research established a callus induction and plant regeneration system for Agrobacterium-mediated CRISPR/Cas9 gene editing in strawberry cv. Benihope by evaluating multiple types of explants and various plant growth regulators throughout the entire tissue culture process. The results showed that the efficiency of callus induction is strongly influenced by the type of explant and is highly sensitive to the combination of plant growth regulators. Among the different plant growth regulators employed, thidiazuron (TDZ), in combination with 2,4-dichlorophenoxyacetic acid (2,4-D), effectively induced callus formation and plant regeneration from explants derived from nutrient tissues such as runner tips and crowns. In addition, the regeneration experiment demonstrated that the addition of polyvinylpyrrolidone (PVPP) to the shoot regeneration medium could inhibit tissue browning. The gene-edited plants in which some or all of the Fvb7-1, Fvb7-2, Fvb7-3, and Fvb7-4 genes in the MLO (Mildew resistance Locus O) gene family were knocked out by CRISPR/Cas9 system were obtained by applying the plant regeneration system developed in this study.

Plant growth regulators improve root growth of rice seedlings after mechanical transplanting and increase grain yield

Summary Enhancing seedling quality and promoting root growth post-transplantation are crucial for improving mechanically transplanted rice productivity. Here we investigated the impact of various plant growth regulators on hybrid and conventional rice varieties. Treatments, including two-diethylaminoethyl hexanoate (DA-6, 10 mg L−1), a combination of potassium 3-indole-butyrate + potassium 1-naphthylacetate + 6-benzylaminopurine (C3, 50 + 50 + 10 mg L−1), potassium 3-indole-butyrate + potassium 1-naphthylacetate + 1-triacontanol (C4, 50 + 50 + 50 mg L−1), potassium 3-indole-butyrate + potassium 1-naphthylacetate + 1.8% sodium nitrophenolate (C5, 50 + 50 + 1 mg L−1), and a combination of potassium 3-indole-butyrate + potassium 1-naphthylacetate + 1.8% sodium nitrophenolate + DA-6 (C6, 50 + 50 + 1 + 10 mg L−1), were sprayed either 3 or 10 days before transplanting. Seedlings sprayed 10 days before transplanting exhibited a higher number of white roots and total roots at the returning green stage, along with increased grain yield, irrespective of the plant growth regulator used. The C6 combination emerged as the most effective treatment, enhancing the growth of both hybrid and conventional rice seedlings, accelerating the growth rate of white roots and total roots, and increasing the length of the longest white root during the greening period, ultimately resulting in higher grain yield. Our findings demonstrate that pre-transplantation application of a combination of plant growth regulators positively influences rice seedling growth.

In Vitro Seed Germination and Seedling Development of Mimusops laurifolia (Forssk.) Friis.: An Endangered Plant Species

Mimusops laurifolia (Forssk.) Friis is an endangered medicinal plant and natural propagation of this plant through seeds is found to be very difficult due to its hard seed coat. To conquer this problem, an efficient in vitro seed germination as well as subsequent in vitro regeneration technique has been developed in conserving this endangered plant species. Seed germination was achieved on half strength of MS (HMS), full strength MS (FMS) and MS medium supplemented with different concentration and combination of Plant Growth Regulators (PGR) like BA, Kn and GA. The highest seed germination rate (18%) was obtained from water soaking de-coated seeds inoculated on full strength of MS (FMS), on the other hand, 12% germination of seeds was recorded on HMS medium, but both the conditions required more than 90 days to germinate. A similar rate of germination was also found on MS with PGRs, but it required 55-60 days. Best responses towards seed germination with elongated shoots (2.8 cm and 3.0 cm) were obtained when seeds were inoculated on MS with 3.0 mg/l BA, 0.5 mg/l Kn and 0.2 mg/l GA. After a long period of period of 8 months following germination, seedlings produced elongated tap roots only. Rooted seedlings were successfully transferred to soil for their further growth and development. Apart from this, for in vitro regeneration of shoots, explants of nodal segments and shoot tips from the natural plant were cultured on woody plant medium (WPM) supplemented with various combination and concentration of BAP, Kn and TDZ. In these cases, there was no positive response recorded towards the initiation of shoots from nodal segment and shoot tips. Plant Tissue Cult. & Biotech. 33(2): 143-153, 2023 (December)

Trends in the Tissue Culture Techniques and the Synthesis of Bioactive Compounds in Eurycoma longifolia Jack-Current Status and Future Perspectives.

Over the last two decades, there has been a concerted effort by researchers to mass propagate Eurycoma longifolia and improve the yield of its very important and sought-after anti-cancer and aphrodisiac bioactive compounds. To achieve this, various techniques have been used to mass propagate and improve the yield of these bioactive compounds in tissue cultures. These techniques include the optimization of media conditions and application of various types and combinations of plant growth regulators (PGRs). In addition, some elicitation techniques have been used to improve the synthesis of these bioactive compounds. However, in comparison with other herbal species with similar economic importance, many techniques have not been applied to E. longifolia. Adopting the most recent methodologies would ensure efficiency and sustainability in the in vitro production of bioactive compounds in E. longifolia. Therefore, in this review, we present an up-to-date record on the success stories in the tissue culture techniques and synthesis of bioactive compounds. In addition, we attempted to identify some of the missing links on the road to the effective and sustainable biotechnological utilization of this super important biological resource.

Studies on Improving the Efficiency of Somatic Embryogenesis in Grapevine (Vitis vinifera L.) and Optimising Ethyl Methanesulfonate Treatment for Mutation Induction.

Somatic embryogenesis (SE) has many applications in grapevine biotechnology including micropropagation, eradicating viral infections from infected cultivars, mass production of hypocotyl explants for micrografting, as a continuous source for haploid and doubled haploid plants, and for germplasm conservation. It is so far the only pathway for the genetic modification of grapevines through transformation. The single-cell origin of somatic embryos makes them an ideal explant for mutation breeding as the resulting mutants will be chimera-free. In the present research, two combinations of plant growth regulators and different explants from flower buds at two stages of maturity were tested in regard to the efficiency of callusing and embryo formation from the callus produced in three white grape cultivars. Also, the treatment of somatic embryos with the chemical mutagen ethyl methanesulfonate (EMS) was optimised. Medium 2339 supplemented with β-naphthoxyacetic acid (5 μM) and 6-benzylaminopurine (BAP-9.0 μM) produced significantly more calluses than medium 2337 supplemented with 2,4-dichlorophenoxyacetic acid (4.5 µM) and BAP (8.9 µM) in all explants. The calluses produced on medium 2337 were harder and more granular and produced more SEs. Although the stage of the maturity of floral bud did not have a significant effect on the callusing of the explants, calluses produced from immature floral bud explants in the premeiotic stage produced significantly more SEs than those from more mature floral buds. Overall, immature ovaries and cut floral buds exposing the cut ends of filaments, style, etc., tested for the first time in grapevine SE, produced the highest percentage of embryogenic calluses. It is much more efficient to cut the floral bud and culture than previously reported explants such as anthers, ovaries, stigmas and styles during the short flowering period when the immature flower buds are available. When the somatic embryos of the three cultivars were incubated for one hour with 0.1% EMS, their germination was reduced by 50%; an ideal treatment considered to obtain a high frequency of mutations for screening. Our research findings will facilitate more efficient SE induction in grapevines and inducing mutations for improving individual traits without altering the genetic background of the cultivar.

Regeneration of Cattleya Amazing Thailand in ½ MS Medium with The Addition of Several Concentration of PGR and Coconut Water

One of the Cattleya species with aesthetic and commercial value is Cattleya Amazing Thailand. An efficient protocol with a high rate of plantlet regeneration is through in vitro culture. Plantlet regeneration is affected by the addition of a Plant Growth Regulator (PGR). Auxin and cytokinin (2,4-D and BAP) combined with PGR from organic material such as coconut water can increase the growth of leave and roots in plantlet regeneration. The research aims to determine the best PGRs combination in regenerating the Cattleya Amazing Thailand orchid in vitro. The research used the Completely Randomized Design (CRD) experimental method for five treatments. The parameter are survival rate, number of leave, and number of roots. Survival rate was analyzed descriptively and both of number of leave and roots were analyzed statistically. All treatments can form 100% plantlets on survival rate parameter. The treatment of 0.1 mg/L 2,4-D + 1 mg/L BAP gave significantly different results in the number of leaf (9.0) and was not significantly different in the number of root. 0.1 mg/L 2,4-D + 1 mg/L BAP is the best combination for in vitro regeneration of the Cattleya Amazing Thailand orchid.

The of Effects of Light and a Combination of Growth Regulators on the Induction of Somatic Embryogenesis in Orchid Rhynchostylis gigantea (LindI.) Ridl.

The squirrel-tail orchid (Rhynchostylis gigantea) belongs to the Orchidaceae family. This orchid is indigenous to Southeast Asia and is scented and arranged in a bouquet of dangling stems. Its uniqueness makes it commercially desirable. In vitro culture has been utilized for orchid proliferation for a very long time to aid in the development of orchid seedlings. However, not all orchid species react the same way. Through somatic embryogenesis without gamete fusion, in vitro culture techniques can produce new plants during the entire embryonic phase. Endogenous and exogenous hormones, as well as light, influence the success of embryogenesis. Determining the optimal environmental parameters (light, combination and concentration of growth regulators, and their interaction) for inducing somatic embryogenesis from leaf explants in R. gigantea is the purpose of the present study. The leaves of R. gigantea clone 19 were utilized as explants in this investigation, utilizing a completely random factorial design. The first factor is a combination of growth regulator types and concentrations, and the second factor is light. Explants that are alive and growing at a rapid rate indicate that the in vitro culture is successful. Light and the combination of growth regulators significantly affected the percentage of viable explants, the beginning date of callus formation, and the number of embryogenic calluses produced. The interaction of two components (light and a combination of growth regulators) did not affect the three characteristics, with the exception of the proportion of somatic embryogenesis. Incubation in the dark is the optimal environment for initiating somatic embryogenesis in explants. The optimal combination of plant growth regulators for inducing somatic embryogenesis was 0.5 mgL-1 TDZ and 0.1 mgL-1 BAP. Bright light and a concentration of 1.0 mgL-1 TDZ + 0.1 mgL-1 BAP were the optimal interaction conditions for the induction of somatic embryogenesis in R. gigantea.

Effect of the Combination of the Growth Regulators and Putrescine on the Somatic Embryogenesis of Wheat (Triticum Aestivum L.) on Some Types of Explants

Plant breeding programs need to be carried out in order to improve the genetics of wheat that is able to adapt to tropical environments through hybridization, mutation induction, tissue culture, and genetic transformation. In vitro culture through somatic embryogenesis pathways plays an important role in genetic improvement and its integration with other breeding programs can positively affect the improvement of wheat quality, quantity, and development in Indonesia. The purpose of this study was to obtain an embryogenic callus induction method from the Dewata variety using five different types of explants, namely mature Seeds, immature embryos, immature seeds, leaf, stem, and to obtain combination of plant growth regulators and putrescine on somatic embryogenesis of wheat. The experimental design was prepared based on a complete randomized design with a combination treatment of embryogenic callus induction media consisting of 9 levels, namely: 1 ppm 2.4- D, 1 ppm 2.4-D + 1 ppm Picloram, ppm 2.4-D + 1 mg / L Picloram, 1 ppm 2.4-D + 10-4 M Putrescine, 1 ppm 2.4-D + 1 ppm Picloram +10-4 M Putrescine, 2 ppm 2.4-D + 1 ppm Picloram + 10-4 M Putrescine, 1 ppm 2.4 D + 10-3 M Putrescine, 1 ppm 2.4 D + 1 ppm Picloram + 10-3 M Putrescine, 2 ppm 2.4 D + 1 ppm Picloram + 10-3 M Putrescine. The results showed that the media used was able to induce embryogenic callus using mature seed and immature embryo, but immature seed and leaf were not able to produce embryogenic callus. The best media that produced the highest percentage of embryogenic callus was 2 ppm 2.4-D + 1 ppm Picloram + 10-4 M Putrescine with as much as 85.9% in young embryo explants.

Efficient in vitro regeneration of Artemisia annua: effect of different combinations of plant growth regulators on various types of explants

The global supply chain of artemisinin for treating malaria relies on the natural population of Artemisia annua. To enhance artemisinin levels in planta, genetic and molecular interventions, and clonal propagation through tissue culture is being explored worldwide. This investigation establishes an efficient protocol for in vitro regeneration by utilizing various plant growth regulators that have significant effects on plant development. Leaf and petiole explants of A. annua were cultured on MS media with different concentrations and combinations of plant growth regulators (PGRs). The highest frequency of callus development (96.13 ± 0.89% response) was observed in explants cultured on MS medium supplemented with 1.0 mg l−1 benzyladenine (BA) and 0.4 mg l−1 thidiazuron (TDZ). The most effective regeneration medium for shoot formation from explants included 0.3 mg l−1 1-naphthaleneacetic acid (NAA) and 2.5 mg l−1 BA, which resulted in a regeneration response of 88.90 ± 2.48%. The MS medium supplemented with 2.0 mg l−1 indole-3-butyric acid (IBA) and 0.5 mg l−1 NAA demonstrated the highest root initiation from the regenerated shoots. These findings have the potential to contribute to the efficient in vitro regeneration of A. annua and facilitate the generation of genetically modified plants with improved artemisinin content.

WORTHY MICROPROPAGATION PROTOCOLS OF SEVEN CULTIVARS OF POMEGRANATE (PUNICA GRANATUM L.) CULTIVARS IN THE PROVINCE OF DUHOK, KURD ISTAN RIGION OF IRAQ.

An efficient attempt was conducted to increase the mass production of seven local cultivars of pomegranate (Punica granatum L.) Masafik, Melisse, Radisho, Armishte, Diala, Halapja, and Dwarf pomegranate cultured in the Kurdistan region of Iraq from October 2021 to February 2023. Micropropagation technique was applied using eight combinations of plant growth regulators (PGRs) added to two media (MS and WPM). The results indicated that immersing explants in 70% Ethyl alcohol (EtOH) for (2 minutes) followed by immersion in (2.5%) Sodium Hypochlorite (NaOCl) plus 3 drops of tween 20 for 13 mins. was the more suitable combination for explant sterilization. MS and WPM media salts supplemented together with eight combinations of PGRs were carried out to evaluate the more suitable combination for the initiation stage. The obtained data clarified that the ½ strength of the MS medium (1/2 MS) supplemented with 0.5 BAP plus 0.5 mg/l Kinetin increases the pomegranate explant initiation response percentage. WPM basal medium was the preferred media to be used in the multiplication stage. The impact of different levels and protocols of Cytokinins, Auxins, and Gibberellins were investigated by eight protocols including using BAP, GA3, and adenine sulfate. The outcomes indicated that adding both concentrations of BAP (0.5 and 1.0 mg/l) separately supported by GA3 and adenine sulfate in amounts of (0.3 and 30 mg/l) respectively again were the most suitable protocol that affected the multiplication of regenerated shoots when compared to using BAP alone. Valuable results were found in rooting response after 6 weeks by using ½ strength of MS media along with two levels of Auxins (NAA, and IBA). Moreover, the visual observation records that around 85-90% of rooted cultures were successfully acclimatized by transferring the cultures from in vitro to the ex-vitro environment. Finally, Dwarf cultivars exceed all the other cultivars in studded parameters.

Effects of plant growth regulators on the callus of rose leaves

In the present study effects of different plant growth regulator combinations on leaf callus growth in two Rosa hybrida cultivars, Rosa hybrida ‘Ingrid Bergman’ and Rosa hybrida ‘Xindongfang’, were analyzed. The plant growth regulators were added into MS, MS + 2,4-D (1.5 mg/l, 2.5 mg/l, 3.5 mg/L, and 4.5 mg/l) and MS + 2.0 mg/l NAA + 1.0 mg/l ZT, MS + 2.0 mg/l NAA + 1.0 mg/l KT, MS + 2.0 mg/l NAA + 1.0 mg/l 6-BA and MS + 2.0 mg/l NAA. The leaves were treated as broken and cultured on these nine different media types. Results showed significant differences in color, morphology, and callus quantity. In the first medium, the callus of rose leaves was the best on MS + 4.5 mg/l 2,4-D medium, followed by MS + 2.5 mg/l 2,4-D and MS + 3.5 mg/l 2,4-D, and finally MS + 1.5 mg/l 2,4-D. No callus was found in MS medium. In the second kind of medium, the leaves grow callus, and the callus grew best on MS + 2.0 mg/l NAA + 1.0 mg/l ZT medium, followed by MS + 2.0 mg/l NAA + 1.0 mg/l KT, finally MS + 2.0 mg/l NAA + 1.0 mg/l 6-BA, MS + 2.0 mg/l NAA medium, the callus grew loose and dry, and lost luster after a few days. Therefore, 2,4-D, KT, ZT, 6-BA, and NAA can promote the formation of callus. With the increase of concentration of 2,4-D, the callus induction rate increased, and the color of the callus also changed significantly. The combination of KT, ZT, and NAA had an obvious effect on callus induction and expansion. Bangladesh J. Bot. 52(3): 867-873, 2023 (September)

Ex vitro shoot induction of rodent tuber (Typhonium flagelliforme) with benzyl amino purine and naphthalene acetic acid

A medicinal plant called rodent tuber has the potential to both prevent and treat various diseases. There is no Standard Operating Procedure (SOP) governing the growth method of rodent tuber because it still grows wild and is rarely cultivated. This research aimed to study the optimal growth of rodent tuber for mass seed propagation based on the type of explants and the concentration of auxin and cytokinin combinations for inducing shoots. While generative parameters (harvesting of tubers/shoots) were observed up to 13 WAP (Week After Planting), vegetative parameters were observed up to 10 WAP. The results showed that the best type of explants for shoot induction and growth of rodent tuber were whole plants with a survival rate of 100%; the number of shoots was 6.65; the plant height was 21.27 cm with 6.34 leaves; 26.56 roots with a length of 16.05 cm; and 40.80% flowering plants. PGR (Plant Growth Regulator) combination of 50 ppm BAP (Benzyl Amino Purine) and 100 ppm NAA (Naphthalene Acetic Acid) became the best explant soaking solution by forming eight shoots and the height of plants was 24.13 cm with seven leaves. The explant produced the highest root length in a combination of 100 ppm BAP and 50 ppm NAA, which was 17.70 cm. The interaction between whole plant explants immersed in 0 ppm BAP and 100 ppm NAA solution resulted in the most significant number of roots (41). Those goals can support the SOP of propagated methods and ensure the consistency, quality, and availability of raw materials for traditional medicine.

The effectiveness of growth regulators and light color spectrum on callus growth of Amorphophallus muelleri Blume. var. Madiun1

Introduction: Plant Growth Regulators (PGRs) play a role in regulating organogenesis and morphogenesis in shoots, roots, and callus formation. Color spectrum of light is one of the quality light factors that affects plant physiological processes. This study aimed to determine the effect of cytokinin and auxin on Murashige-Skoog (MS) medium and light on callus induction and proliferation of porang (Amorphophallus muelleri Blume.) var. Madiun1. Methods: This study used completely randomized design, with the first factor was PGRs (combination auxin and cytokinin) and the second was color spectrum of light (white light, blue light, and its combination) during incubation. Variables observed were emergence time, color, texture, structure and calli growth, also shoots emerging from calli. Results: The results showed an interaction between PGRs with a combination of light color spectrum on callus growth. The fastest callus growth occurred in combination 5.0 mg.l-1 6-benzyl amino purine (BAP) with 0.2 mg.l-1 naphthalene acetic acid (NAA) which was incubated in a combination of white and blue light for 16 hour irradiation. The combination 5.0 mg.l-1 BAP with 0.2 mg.l-1 NAA was able to induce callus emergence time, and the shoots appearing were faster, whereas combination of white and blue light was able to accelerate callus emergence from bulbil and adventitious shoots emergence. Conclusion: The combination of white and blue light color spectrum for 16 hours irradiation can accelerate callus emergence from bulbil and adventitious shoots emerging from calli, and interaction with combination of 5.0 mg.l-1 BAP and 0.2 mg.l-1 NAA can accelerate porang’s callus growth.

Somatic Embryogenesis and Plant Regeneration from Stem Explants of Pomegranate

Plant regeneration through somatic embryogenesis provides a solution for maintaining and genetically improving crop or fruit varieties with desirable agronomic traits. For the fruit tree pomegranate (Punica granatum L.), despite some successful applications, the existing somatic embryogenesis protocols are limited by low availability of explants and susceptibility to browning. To address these problems, in this study, we developed an effective system for induction of high-vigor pomegranate somatic embryos derived from stem explants. The usage of stem explants breaks through the difficulty in obtaining material, thus making our system suitable for widespread commercial production. To enhance the performance of our system, we identified the optimal explants, subculture cycles and combination of basal media and plant growth regulators for each step. The results showed that inoculating stem explants onto a Murashige and Skoog (MS) medium supplemented with 1.0 mg/L 6-benzylaminopurine (6-BA) and 1.0 mg/L 1-naphthaleneacetic acid (NAA) achieved the best induction rate and growth status of pomegranate calli (induction rate = ~72%), and MS medium containing 0.5 mg/L 6-BA and 1.0 mg/L NAA was the optimal condition for the induction of embryogenic calli and somatic embryos (induction rate = ~74% and 79%, respectively). The optimal subculture period for embryogenic calli was found to be 30–35 days. Strong roots were then induced in the developed somatic embryo seedlings, which survived and grew well after transplantation to the natural environment, indicating the good vitality of the induced pomegranate somatic embryos. Together, our system provides a solution to mass somatic embryo induction and plant regeneration of pomegranate and lays a foundation for future genetic transformation and bioengineering improvement of pomegranate with favorable agronomic traits.

Use of Light Spectra for Efficient Production of PLBs in Temperate Terrestrial Orchids

Wild orchids, especially the terrestrial temperate ones are endangered species due to challenges in their natural habitats. Therefore, there is an urgent need to introduce efficient propagation methods to overcome the natural reproduction problems of these orchids. In this study, the effects of different light spectrums, explant types, wounding, and combinations of different plant growth regulators (PGRs) on direct somatic embryogenesis (DSE) of two species of these endangered orchids listed in the conservation category, were studied. The highest percentages of DSE formation and embryo germination were observed in Dactylorhiza umberosa protocorm explants exposed to white light (400–730 nm) and in Epipactis veratifolia protocorm explants exposed to a combination of red and far-red spectra (R: FR = 70:30). This occurred while red (610–700) alone and in combination with far-red (710–730 nm) spectrum induced embryogenesis more than the blue spectrum and dark condition in E. veratifolia. Thidiazuron (TDZ, 3 mg L−1), produced the highest percentage of protocorm-like bodies (PLBs) on protocorm explants in both orchids. Kinetin (Kin, 2 mg L−1) and Benzyladenine (BA 3 mg L−1) had the most effect on the survival and growth of PLBs, respectively, in D. umberosa and E. veratifolia. Species did not show similar embryogenesis responses under light spectrums. In a medium containing 3 mg L−1 TDZ, white light and R-FR spectra produced the most PLBs on wounded protocorm explants of D. umberosa and E. veratifolia respectively. The developmental stage of apical meristem of PLBs in both species was more advanced under R-B spectra, compared to others.

Callogenesis of Dayak Onion (Eleutherine palmifolia) Bulb in response of Picloram, 2,4-D, and Kinetin

Dayak onion contains bioactive compounds that are traditionally used for medicine. The production of bioactive compounds can be increased through callus culture. This study aims to analyze the effect of the combination of plant growth regulator on the growth of Dayak bulb callus. The design of this study used a completely randomized factorial design with 2 factors. The first factor is the concentration of auxin. While the second factor is the concentration of kinetin. The parameters observed include the percentage of callus, the time of callus formation, fresh weight, dry weight, and callus morphology. In this study, a callus growth curve was also made to determine the best harvest time. The results showed that highest callus fresh weight was obtained in the P3K1 treatment. The percentage of callus formation in the picloram + kinetin treatment was higher than in the 2,4-D + kinetin treatment. The time of callus formation occurred in the combination of picloram + kinetin faster than the 2.4-D + kinetin treatment. The callus color is diverse, while the texture of the entire callus is compact. The best callus induction medium for Dayak onion bulbs is to use picloram 2-4 ppm + kinetin0.025-0.5 ppm. The results of this study provide optimal growth regulatory information for the induction of dayak onion callus that has never been reported before. This information can be the basis for the development of methods of production of bioactive compounds from dayak onions through callus culture.

Effect of Growth Regulators on Plant Growth and Flower Yield in Marigold (Tagetes erecta)

A field experiment was carried out in the Department of Horticulture, Naini Agricultural Institute, Sam Higginbottom University of Agriculture, Technology and Sciences, Prayagraj. During rabi season (2022-2023). The aim of this study was to determine the effect of different growth regulators on plant growth, flowering and flower yield of African marigold and to estimate the economics of different treatments. This experiment was laid out in Randomized block design (RBD) with 10 treatments and each treatment replicated thrice. The treatments consist of different combinations of plant growth regulators (Gibberellic acid, Salicylic acid and Sea weed extract). Treatment T3 (Gibberellic acid @150ppm) was statistically significant compared to other treatment combination, which recorded highest plant height (44.11 cm), no. of branches (43.53), stem diameter (1.61 cm), no. of leaves (118.93), plant spread (37.17 cm2), Bud length (0.93cm), days to 1st flowering (66.07 days), Size of flower (8.77cm), Number of flower per plant (34.10), Self-life (8.67 days), single flower wt. (18.28 g) in African marigold (Tagetes erecta). The economics estimation revealed that maximum benefit cost ratio was at 2.44.