Combinations Of Plant Growth Regulators Research Articles

Phytochemical Profiles and Cytotoxic Activity of Bursera fagaroides (Kunth) Engl. Leaves and Its Callus Culture.

Bursera fagaroides, popularly used in México, possesses bioactive lignans. These compounds are low in the bark, and its extraction endangers the life of the trees. The aim of the present investigation was to search for alternative sources of cytotoxic compounds in B. fagaroides prepared as leaves and in vitro callus cultures. The friable callus of B. fagaroides was established using a combination of plant growth regulators: 4 mgL-1 of 2,4-dichlorophenoxyacetic acid (2,4-D), 1 mgL-1 Naphthaleneacetic Acid (NAA) and 1 mgL-1 Zeatin. The maximum cell growth was at day 28 with a specific growth rate of μ = 0.059 days-1 and duplication time td = 11.8 days. HPLC quantification of the dichloromethane callus biomass extract showed that Scopoletin, with a concentration of 10.7 µg g-1 dry weight, was the main compound inducible as a phytoalexin by the addition of high concentrations of 2,4-D, as well as by the absence of nutrients in the culture medium. In this same extract, the compounds γ-sitosterol and stigmasterol were also identified by GC-MS analysis. Open column chromatography was used to separate and identify yatein, acetyl podophyllotoxin and 7',8'-dehydropodophyllotoxin in the leaves of the wild plant. Cytotoxic activity on four cancer cell lines was tested, with PC-3 prostate carcinoma (IC50 of 12.6 ± 4.6 µgmL-1) being the most sensitive to the wild-type plant extract and HeLa cervical carcinoma (IC50 of 72 ± 5 µgmL-1) being the most sensitive to the callus culture extract.

A highly efficient organogenesis system based on 6-benzylaminopurine and indole-6-butyric acid in Suaeda glauca-a medicinal halophyte under varying photoperiods

Suaeda glauca (Bunge) is a pivotal halophyte species, well-known for its rich nutrient content and its importance as a superior vegetable and oil crop, offering significant health benefits for both human and animal consumption. However, the absence of an efficient regeneration technique has severely hindered its genetic development. Consequently, there is an urgent need to establish an effective in vitro organogenesis initiation method for this valuable plant. In this study, our primary objective was to develop a comprehensive protocol for micropropagating S. glauca, primarily capitalizing on the synergistic effects of 6-benzylaminopurine (6-BAP) and indole-6-butyric acid (IBA). We explored the impact of different combinations of 6-benzylaminopurine (6-BAP), 2,4-dichloroacetic acid (2,4-D), and IBA on callus induction, organogenesis, and rooting using various explants (cotyledons, hypocotyls, and leaves) under two different photoperiod regimes during in vitro culture. Our results unveiled noteworthy variations in several variables related to organogenesis. The optimal combination of plant growth regulators (PGRs) for inducing embryonic callus from cotyledon (COT) was pinpointed at 4.44 μM 6-BAP and 2.71 μM 2,4-D. By employing 6-BAP concentrations ranging from 8.88 μM to 13.33 μM, alongside 0.49 μM IBA, 3% sucrose, and 0.3% phytagel in full MS media under light conditions, we achieved a remarkable 100% regeneration rate through the direct organogenesis pathway. Our findings underscore the pivotal role of 6-BAP in triggering multiple shoots and attaining a 3.6% callus differentiation rate, while 0.98 μM IBA resulted in a 65.28% root induction rate, facilitating the successful acclimatization of plants. Based on the synergistic effects of 6-BAP and IBA, we propose a robust protocol for S. glauca organogenesis, which holds great promise for streamlining micropropagation in S. glauca tissue culture. This standardized protocol has the potential to advance genetic improvement and promote the commercial cultivation of S. glauca as a valuable halophyte species.

An Efficient Micropropagation Protocol For Mucuna Pruriens (L.) Dc.

An efficient protocol was developed for rapid micropropagation of Mucuna pruriens (L.) DC., an important medicinal plant species of Bangladesh. For the purpose, leaf segments, nodal segments and shoot apices of in vitro grown seedlings and cotyledon segments of immature seeds of field grown plants were cultured on agar solidified MS medium supplemented with different combinations of PGRs (Plant Growth Regulators). Only leaf and cotyledon segments produced light green to green friable/ compact callus in some of the media combinations. Combination and concentration of PGRs played important role in induction of such tissue. The induced tissues failed to differentiate on further culture in a wider spectrum of PGR supplemented media. On the other hand nodal segments and shoot apices produced multiple shoot buds when grown on a wide range of PGRs (BAP, NAA, IAA, Kn) supplemented media. Maximum number of multiple shoot buds were produced in medium containing 1.5 mg/l BAP + 1.0 mg/l IAA. The elongated shoot buds on further culture in rooting media produced strong and stout root systems. Half strength MS media fortified with either 1.0 mg/l IAA or 2.0 mg/l IAA was most effective for induction and proliferation of roots. These complete plantlets were successfully acclimatized and established in outside pots through a successive phase of acclimatization. The Chittagong Univ. J. B. Sci.,Vol. 7(1 &2):79-89, 2012.

Mass Scale Micropropagation Of Andrographis Paniculata (Burm. F.) Wall Ex Nees

A reliable and efficient protocol was developed for in vitro propagation of Andrographis paniculata (Burm. f.) Wall ex Nees with the use of nodal and shoot tip explants. Nodal segments and shoot apex of in vitro grown seedlings were cultured on agar solidified MS medium supplemented with different concentrations and combinations of plant growth regulators (PGRs). Both the explants underwent direct organogenesis and produced multiple shoot buds. In case of shoot apex, maximum number of multiple shoot buds were formed when cultured on MS medium containing 1.5 mg/l Kn + 1.0 mg/l IAA. But nodal segments produced highest number of shoot buds on MS medium fortified with 1.5 mg/l BAP + 1.0 mg/l IAA. Multiple shoot buds underwent rapid elongation on elongation media and maximum elongation took place on MS medium fortified with 2.0 mg/l Kn + 1.5 mg/l IAA. Elongated shoot buds, on further culture in rooting media, produced strong and stout root systems. Half strength MS medium fortified with 2.0 mg/l IAA was most effective for induction and proliferation of roots. The healthy complete plantlets were successfully acclimatized and established in outside pots through successive phases of acclimatization. The Chittagong Univ. J. B. Sci.,Vol. 7(1 &2):121- 130, 2012.

Biochemical properties and pigment contents of Satureja genotypes affected by plant growth regulators and temperature stress.

There is little data, to our knowledge, on the biochemical properties of different Satureja sp. genotypes affected by plant growth regulators (PGR) under temperature stress. A split plot research on the basis of a complete randomized block design with three replicates examining temperature stress (planting dates, 8th of April, May and June) (main factor), and the factorial combination of plant growth regulators (PGR, control (CO), gibberellic acid (GA), fertilization (MI), and amino acid (A)), and genotypes (Khuzestani, Mutika, and Bakhtiari) on plant biochemical properties, was conducted. Plant pigment contents (chlorophyll a, and b and carotenoids (car)), antioxidant activity (catalase (CAT), ascorbate peroxidase (APX) and guaiacol peroxidase (GP)), and leaf protein were determined. Treatments significantly and differently affected the genotypes performance. PD3 and PD1resulted in significantly higher activity of APX (0.059 U. mg-1) and GP (0.190 U. mg-1), respectively (P ≤ 0.05). Temperature stress significantly affected plant CAT activity (U. mg-1) at PD1 (0.084) and PD3 (0.820). Higher temperature significantly enhanced leaf Pro, MI increased plant APX (0.054) and CAT activities (0.111 U. mg-1) significantly, and GA resulted in the highest and significantly different GP activity (0.186 U. mL-1). Treatments T1 and T3 significantly enhanced Chla and Car content, and MI resulted in significantly higher Chlb content (0.085mgg-1 leaf fresh weight). Car and CAT are the two most sensitive biochemical traits under temperature stress and can more effectively regulate Satureja growth and activity. It is possible to alleviate temperature stress on Satureja biochemical properties by the tested PGR.

A Comprehensive Study on the Micropropagation of Costus igneus: Media Composition, Growth, and Development

Costus igneus, commonly known as insulin plant, is an ornamental plant valued for its spiral ginger- like foliage and medicinal properties. Micropropagation is an efficient method for rapid multiplication of Costus igneus. This study aims to determine the optimal media composition and culture conditions for in vitro propagation of C. igneus. Axillary bud explants were cultured on Murashige and Skoog (MS) medium supplemented with different concentrations and combinations of plant growth regulators including auxins (indole-3-acetic acid, indole-3-butyric acid and naphthaleneacetic acid) and cytokinins (6- benzylaminopurine and kinetin). Microshoots cultured on MS + 1.5 mg/L BAP showed the highest shoot proliferation rate (98%) and maximum number of shoots per explant (12.6). Elongated microshoots were rooted on half-strength MS medium supplemented with different auxins. The highest rooting percentage (95%) and maximum number of roots per shoot (9.8) were observed on medium containing 2.5 mg/L IBA. The regenerated plantlets were acclimatized and successfully transferred to pots with 80% survival rate. Morphological and phytochemical analysis showed no significant differences between the in vitro propagated and mother plants. This study demonstrates the potential of micropropagation for large scale production of quality planting material of C. igneus. Further studies on genetic and epigenetic stability are recommended to validate this protocol for commercial applications.

In Vitro Shoot Multiplication and Rooting of 'Kashan' and 'Hervy Azerbaijan' Damask Rose (Rosa damascena Mill.) Genotypes for Cosmetic and Ornamental Applications.

The damask rose (Rosa damascena Mill.) is an ornamental-medicinal plant from the Rosaceae family, and its aromatic compounds and essential oils are applied globally in the food, cosmetic, and pharmaceutical industries. Due to its economic value, this research aimed to establish a protocol for an efficient, rapid, and cost-effective method for in vitro shoot multiplication and rooting of the R. damascena 'Kashan' and 'Hervy Azerbaijan' genotypes. Nodal segments (as primary explants) were cultured on the Murashige and Skoog (MS) medium with combinations of various plant growth regulators (PGRs) such as gibberellic acid (GA3), 6-benzylaminopurine (BAP), and indole-3-butyric acid (IBA), as well as a PGR-like substance, phloroglucinol (PG), vitamins such as ascorbic acid (AA), and activated carbon in the form of active charcoal (AC). For the establishment stage, 0.1 mg·L-1 PG, 0.2 mg·L-1 GA3, and 1 mg·L-1 BAP were added to the media. Secondary explants (nodal segments containing axillary buds produced from primary explants) were obtained after 30 days of in vitro culture and transferred to the proliferation media supplemented with different concentrations of BAP (0, 0.5, 1, 1.5, 2, and 2.5 mg·L-1) and GA3 (0, 0.1, 0.2, 0.4, 0.8, and 1 mg·L-1) together with 0.1 mg·L-1 PG and 20 mg·L-1 of AA. The rooting media were augmented with different concentrations of BAP and GA3 with 0.1 mg·L-1 of IBA, PG and 20 mg·L-1 of AA and AC. The results showed that the highest regeneration coefficient (4.29 and 4.28) and the largest number of leaves (23.33-24.33) were obtained in the explants grown on the medium supplemented with 2 mg·L-1 BAP and 0.4 mg·L-1 GA3 for the 'Kashan' and 'Hervy Azerbaijan' genotypes, respectively. Likewise, this PGR combination provided the shortest time until bud break (approximately 6.5 days) and root emergence (approximately 10 days) in both genotypes. The highest number of shoots (4.78 per explant) and roots (3.96) was achieved in this medium in the 'Kashan' rose. Stem and root lengths, as well as stem and root fresh and dry weights, were also analyzed. In most measured traits, the lowest values were found in the PGRs-free control medium. Rooted plantlets were transferred to pots filled with perlite and peat moss in a 2:1 proportion and were acclimatized to ambient greenhouse conditions with a mean 90.12% survival rate. This research contributes significantly to our understanding of Damask rose propagation and has practical implications for the cosmetic and ornamental plant industries. By offering insights into the manipulation of regeneration processes, our study opens up new possibilities for the effective production of high-quality plant material.

Enhancing the phytoextraction efficiency of heavy metals in acidic and alkaline soils by Sedum alfredii Hance: A study on the synergistic effect of plant growth regulator and plant growth-promoting bacteria

Plant growth regulators (PGR) and plant growth-promoting bacteria (PGPB) have the potential in phytoremediation of heavy metals (HMs) contaminated soils. However, their sole application may not yield the optimal results, thus necessitating the combined application. The present study aimed to enhance the phytoremediation efficiency of Sedum alfredii Hance (S. alfredii) in acidic and alkaline soils through the combination of PGR (Brassinolide, BR) and PGPB (Pseudomonas fluorescens, P. fluorescens). The combination of BR and P. fluorescens (BRB treatment) effectively increased the removal efficiency of S. alfredii for Cd, Pb, and Zn by 355.2 and 155.3 %, 470.1 and 128.9 %, and 408.4 and 209.6 %, in acidic and alkaline soils, respectively. Moreover, BRB treatment led to a substantial increase in photosynthetic pigments contents and antioxidant enzymes activities, resulting in a remarkable increase in biomass (86.71 and 47.22 %) and dry mass (101.49 and 42.29 %) of plants grown in acidic and alkaline soils, respectively. Similarly, BRB treatment significantly elevated the Cd (109.4 and 71.36 %), Pb (174.9 and 48.03 %), and Zn levels (142.8 and 104.3 %) in S. alfredii shoots, along with cumulative accumulation of Cd (122.7 and 79.47 %), Pb (183.8 and 60.49 %), and Zn (150.7 and 117.9 %), respectively. In addition, the BRB treatment lowered the soil pH and DTPA-HMs contents, while augmenting soil enzymatic activities, thereby contributing soil microecology and facilitating the HMs absorption and translocation by S. alfredii to over-ground tissues. Furthermore, the evaluation of microbial community structure in phyllosphere and rhizosphere after remediation revealed the shift in microbial abundance. The combined treatment altered the principal effects on S. alfredii HMs accumulation from bacterial diversity to the soil HMs availability. In summary, our findings demonstrated that synergistic application of BR and P. fluorescens represents a viable approach to strengthen the phytoextraction efficacy of S. alfredii in varying soils.

Establishment of plant regeneration protocol through callus induction of sugarcane (Saccharum officinarum l.) var. China using leaf-sheath

Establishment of a plant regeneration system through direct organogenesis or via callus is also a prerequisite to further in vitro genetic manipulation of the cultivar through somaclonal variation, in vitro mutagenesis and genetic transformation. Production of sufficient numbers of plants of a unique genotype is possible using in vitro culture system. In this study, the effect of various concentrations and combinations of plant growth regulators for in vitro regeneration of sugarcane via callus was described using leaf-sheath as explants. Thus, a reproducible protocol for induction of callus and regeneration into plantlets were developed in sugarcane var. china using leaf-sheath as explants. Potential callus induction was observed on MS medium supplemented with 4.5 mg/l 2,4-D, in which 80% explants induced callus after culture initiation of 90 days. Shoot formation from the callus was optimum on MS + 1.0 mg/l GA3 + 0.5 mg/l Kin., in which 70% of the cultured calli formed shoots. The average number of shoot formed per culture callus was 27.0 ± 2.50 and the average shoot length of 6.5 ± 0.50 cm were achieved in this medium after culture of 60 days. Regenerated shoots rooted well when they were transferred into half strength of MS + 2.50 mg/l NAA, in which 90% shoots rooted within 30 days of culture. The average number of root produced per shoot was 18.0 ± 2.25 and the average root length of 7.50 ± 1.20 cm were observed in this medium. Ninety percent of the in vitro raised plantlets were survived in the natural environment.

Exploring somatic embryogenesis in Ajuga multiflora Bunge: Profiling lipophilic metabolites via HPLC, GC-FID, and GCMS– analysis

The present study aims to assess the effect of different concentrations of auxins and combinations of plant growth regulators (PGRs), specifically auxin and cytokinin, on somatic embryogenesis in Ajuga multiflora. We also aim to compare the lipophilic metabolite profiles, such as carotenoids (CAs), fatty acids (FAs), phytosterols (PSs), and tocopherols (TPs), in globular somatic embryos (SEs), germinated SEs, and shoots of SEs derived plantlets. This assessment is carried out utilizing high performance liquid chromatography, gas chromatography-flame-ionization detection, and gas chromatography–mass spectrometry techniques. The results reveal that the application of 2,4-dichlorophenoxyacetic acid (2,4-D) had the most significant impact on somatic embryogenesis, inducing both SE initiation (34.4%) and the number of SEs (3.5) per explant. Among the explants used, leaf explants were found to be the most effective for SE induction (SEI). Additionally, the study explores the combined effect of 2,4-D and cytokinins (N6-benzyladenine, N6-BA, or 1-phenyl-3-(1,2,3-thiadiazol-5-yl) urea, TDZ) on somatic embryogenesis, highlighting optimal conditions for SEI percentages and the number of SEs per explant. The maximum SE induction rate (100%) and the number of SEs (45.9) per leaf explant were obtained on an SEI medium with 30 µM of 2,4-D and 2.3 µM of TDZ. The maturation and conversion of SEs were also examined, emphasizing the role of GA3 in achieving the highest conversion percentage (94.0 ± 2.7 at 0.8 µM GA3). Furthermore, the study details the biochemical composition during various stages of somatic embryogenesis, including CAs, TPs, PSs, and FAs. Globular SEs displayed comparatively lower concentrations of CAs than their germinated counterparts and shoots from SE-derived plantlets, while the total PSs content remained relatively consistent across all stages. Conversely, fatty acids tended to accumulate more in globular SEs, with the exception of α-Linolenic acid. These findings provide valuable insights into the optimization of somatic embryogenesis protocols in A. multiflora, with implications for plant tissue culture, regeneration and lipophilic metabolites production.

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.