Shoot Tip Explants Research Articles

Thidiazuron induces high-frequency plant regeneration from shoot tip explants of an ornamental aquatic plant, Anubias barteri var. nana

ISHS IX International Scientific and Practical Conference on Biotechnology as an Instrument for Plant Biodiversity Conservation (physiological, biochemical, embryological, genetic and legal aspects) Thidiazuron induces high-frequency plant regeneration from shoot tip explants of an ornamental aquatic plant, Anubias barteri var. nana

In vitro propagation of Bambusa balcooa by plant tissue culture technique

Bambusa balcooa is a common plant grown in Bihar, Orissa, Jharkhand and Uttarakhand states of India having good cultural importance. The present experimentation on nodal explants of B. balcooa on MS media supplement under particular culture conditions has shown shunted growth in 30 days. Shoot tip explants of B. balcooa seedlings produced multiple shoots on MS medium supplemented with different plant growth regulators (PGRs) individually and in combination. Shoot tip explants of B. balcooa requires 30 days to initiate shoots. Among the three cytokinins tested, BAP was selected as the most suitable hormone to induce shoot multiplication. The highest shoot multiplication is found by incorporation with BAP (1.5 µg/L and 2 µg/L). The shoot multiplication rates are good with shoot length 2.5±0.3 cm and 3.9±0.4 cm with the highest and maximum shoot generation. The shoot multiplication rate is moderate with a shoot length of 2.00±0.5 cm. Multiplication potentiality was observed in the cluster having more than 2–3 shoots. The best period for recycling multiplying shoots is 2–3 weeks in the old culture. Delaying of the sub-culturing period resulted in gradual browning of the shoots. The sub-culturing period was recorded as the most crucial factor for obtaining the optimal and desired level of regeneration of shoots. The well-grown propagules in the present experimentation were shown successful regeneration. Hence, the experiment concluded with the best growth pattern observed in media containing auxins like BAP and cytokinins like kinetin.

Optimization of Conditions for In Vitro Culture of Selected Arbutus unedo L. Genotypes

The strawberry tree is an evergreen shrub tree that grows on sea-facing slopes under a Mediterranean climate. It has a key role in the lives of the rural inhabitants of forested areas and is one of the most promising species for developing new approaches in cultivation for improved fruit. As a result of the growing interest of farmers, selection studies have focused on the selection of highly productive varieties of Arbutus unedo, whereby there is a requirement for the selected varieties to be propagated at a large scale. In this study, the in vitro propagation potential of the selected A. unedo genotypes, YV2 and YV4, was investigated. The best results in terms of decreasing browning with a high level of sterilization were achieved with 50% ethanol (1 min) and 20% NaCIO (12 min) for both shoot tip and nodium explants. In terms of growth performance, both genotypes displayed the highest proliferation rate in WPM medium-supplemented with BAP (2.0 mg/L) and with added IBA and GA3 (0.1 mg/L each), in which the shoot number and elongation were also the highest. YV2 microcuttings showed higher rooting rates when cultured in WPM medium, with an added 2.0 mg/L IBA, whereas the addition of 4.0 mg/L NAA was optimal for YV4. The resulting root quality was sufficient for surviving the acclimatization stage. The genotype effect was clear in all stages during the in vitro propagation for all growth parameters.

Accelerated mono-phasic in vitro mass production of banana propagules and their morpho-cyto-genetic stability assessment

A unique one-step in vitro propagation protocol via concurrent shoot-root development was established in banana cv. Grand Nain. 6-benzyladenine, kinetin, meta-Topolin, thidiazuron (TDZ), and zeatin (0.5—1.5 mg L − 1) individually supplemented in Murashige and Skoog medium were tested for multiple shoot-root regeneration from shoot tip explants. The earliest fresh shoot (∼7 days) and root (∼5 days) initiation, highest number of shoots (∼21) and roots (∼16) with maximum root elongation (16.5 cm) were recorded in 0.5 mg L − 1 TDZ. For all intents and purposes, TDZ (0.5 mg L − 1) was recorded to be the optimum formulation in terms of the highest simultaneous shoot and root formation that was corroborated further by matrix plot analysis. On the other hand, network plot analysis and principal component analysis illustrated the association between plant growth regulators based on their effect on growth attributes under study. Histological studies on shoots, roots, and leaves revealed a consistent growth and development of plantlets under in vitro condition. Cent percent plantlets were survived during acclimatization, and performed best in cocopeat in comparison to other substrata (vermiculite, perlite, vermicompost-soil, soil-sand, and sand only). The cytology-, flow cytometry- and ISSR primer-assisted fidelity assessments of the in vitro-regenerants exhibited numerical chromosomal as well as ploidy stability and monomorphic banding patterns without any polymorphism within the in vitro-regeneranted plantlets and with their mother plant. Based on the comprehensive information developed in this study, this protocol should be of immense importance to facilitate single-step large-scale production of true-to-type planting materials and to explore the possible comparative physico-chemical roles of the plant growth regulators used in this study.

High Frequency in vitro Plantlet Regeneration from Leaf, Node and Shoot Tip Explants of Corynandra felina (L.f.) Cochrane & Iltis, an Important Endemic Medicinal Plant in Peninsular India

High Frequency in vitro Plantlet Regeneration from Leaf, Node and Shoot Tip Explants of Corynandra felina (L.f.) Cochrane & Iltis, an Important Endemic Medicinal Plant in Peninsular India

Characterization and maintenance of promising gynoecious bitter gourd line through hormonal regulation and micropropagation

New gynoecious bitter gourd line, KAU-MCGy-101 identified from Kerala Agricultural University, India, was morphologically characterized. Silver thiosulphate (STS) was used for altering the sex expression of gynoecious line. STS induced hermaphrodite flowers in gynoecious plants and maximum number of hermaphrodite flowers was in plants receiving single spray at 200 ppm after emergence of first female flower. F1 was generated by crossing with monoecious variety Preethi and all the hybrids were monoecious in nature. Expression of gynoecious character in the sib-mated gynoecious inbred and monoecy in F1 hybrids, indicate the recessive nature of gynoecy in bitter gourd. Gynoecious inbred was also maintained through micropropagation. The shoot tip explants cultured on MS medium supplemented with 2.0 mgL−1 BA followed by 1.5 mgL−1 BA have given the highest shoot initiation response in 20.75 days. Multiple shoots, up to 5.50 per explant, were induced on MS medium with 2.0 mgL−1 BA and microshoots elongated best with 0.5 mgL−1 IAA + 0.5 mgL−1 NAA. Best in vitro rooting was on half strength MS medium with 3.0 gL−1 activated charcoal and 1.0 mgL−1 IBA. The gynoecious expression was found to be stable in tissue culture regenerated progenies.

Somatic embryogenesis and plant regeneration from shoot tip explants of Buchanania lanzan

Somatic embryogenesis and plant regeneration from shoot tip explants of Buchanania lanzan

In vitro Propagation of Banana (Musa paradisiaca L.) Plant Using Shoot Tip Explant

Banana is a fruit crop which has high demand in Ethiopia, but its production is constrained by lack of disease free planting material with conventional propagation methods. For shoot initiation, shoot tip explants were cultured on MS medium supplemented with 0.5, 1.0, 1.5 and 2.0 mg/L BAP. Similarly, MS medium supplemented with BAP at 1.0, 1.5, 2.0 mg/L in combination with IBA at 0.25 and 0.50 mg/L were used for shoot multiplication. Half- strength MS medium augmented with IBA at 1.0, 2.0, 3.0 and 4.0 mg/l were used for root induction. MS medium without PGRs were used as controls. Finally, hardening of the in vitro derived plantlets was carried out in green house both in the primary and secondary acclimatization stages. Results showed that the highest shoot initiation percent (93.40%), highest mean number of shoots per explant (4.67) and lesser day for shoot induction (11.00) were observed in explant cultured on MS + 1.0 mg/L BAP. With shoot multiplication, highest shooting percent (92.60%), maximum number of shoots (7.67) and highest shoot length (5.27 cm) were recorded on MS + 1.5 mg/L BAP + 0.5 mg/L IBA. The highest rooting percent (93.40%), maximum root number per shoot (7.67) and highest root length (11.00 cm) were found on a half strength MS medium + 2.0 mg/L IBA. The survival rate of plantlets were 96.00% in coco peat substrate in primary acclimatization and 97.92% in forest soil, sand and manure substrates mixed at 3:2:1 ratio in secondary acclimatization. Overall, the result showed that the PGRs type, concentrations and combinations used are effective for mass propagation of banana variety studied in this experiment.

Effects of different BA and IBA concentrations on proliferation and rooting of ‘GARNEM’ rootstock in vitro propagation

In this study, the regeneration shoot tip and nodal explants grown in vitro conditions of ‘Garnem’ hybrid rootstock were investigated, the effect of different phytohormone and concentrations on obtaining adventitious shoots from different explants was investigated, so an efficient protocol was developed for in vitro regeneration of ‘Garnem’ hybrid rootstock These outputs of the study can be a reference resource for future in vitro and biotechnological studies on the rootstock in question. The differences of PGR in MS medium culture containing node explants infinite (0.5-2.0 mg / l) BA (benzyladenine) were investigated. Upon the research, it was observed that the number of shoots andproliferationwere achieved in explants of nodal cuttings that were taken to culture in MS medium containing 2.0 mg / l BA. It has been determined that the most effective culture medium for the elongation of shoot length is MS medium containing 0.5 mg / l BA, 30 g / l sucrose and 5.5 g / l agar. Shoots growing in length were transferred to a new culture with ½ MS medium 0.5-2.0 mg / l IBA (indole-3-butyric acid) to be rooted. While rooting at a rate of 42.8% was achieved in ½ MS medium containing 2 mg / l IBA, 47.2% of rooted plantlets were acclimatized to ex- vitro conditions. Rooted plantlets obtained under in vitro conditions were transferred to plastic containers with 3 different environments in order to get accustomed to external conditions. At the end of the 8th week, the vitality rates of the plantlets were determined. While the viability rate of the plantlets transferred to the medium containing peat: perlite at the ratio of 1: 1 was found to be 47.2%, the viability rate of the plantlets in the environment containing only perlite was found to be 32.8%, and the viability rate of the plantlets in the environment containing only peat was found as 23.6%

Multiple shoot induction and regeneration of Vanilla borneensis Rolfe - a critically endangered orchid of Assam, India

In the present investigation, a micropropagation protocol has been developed for Vanilla borneensis Rolfe – a critically endangered orchid through multiple shoot regeneration. Through in vitro multiple shoot regeneration from both nodal and shoot tip explants, maximum (100%) shoot induction was observed. The minimum time required for shoot bud induction was observed from the shoot tip (5–7 days) on medium supplemented with BAP (4.44 mM) + KIN (2.32 mM) as compared to the nodal explants. Maximum multiple shoot regeneration was observed from nodal explants on the medium supplemented with BAP (4.44 mM) + TDZ (6.82 mM). However, maximum shoot length was observed on the medium supplemented with BAP (4.44 mM) + 15% CW and the number of nodes (5.27±0.33) per shoot after 90 days. Maximum (80-100%) of root initiation was observed in almost all the concentrations of NAA. The shortest time of root initiation was found on the medium supplemented with NAA (5.37 mM). Further, acclimatization period was found to be 15 days with 70% acclimatization while 60% of survivability was observed in the field condition. This efficient micropropagation method of V. borneensis could be successfully used for mass propagation as well as conservation of the critically endangered wild orchid.

In Vitro Effects of Different Combinations of Phytohormones on Callus Induction from Different Explants of Cabbage Brassica Oleracea Var. Capitata L. Seedlings

The leading purpose of this work is the development of efficient culture conditions to induce calli from cabbage (Brassica oleracea var. capitata L.) under in vitro conditions. The mature seeds were surface sterilized with combinations of different concentrations of ethanol and NaOCl in different time durations and were germinated on MS basal medium. The results revealed that the best sterilization method of cabbage seeds was by using 70% ethanol for one minute, followed by 15 min in 2% (NaOCl). Seedlings were used as donor sources for hypocotyls, cotyledon leaves, true leaves, and shoot tip explants. These explants were cultured on different combinations of cytokinins (TDZ, BAP, Ad) and auxins (IAA, NAA, 2, 4-D) then implanted in Murashige and Skoog (MS) media. 4 weeks after culturing, a significant difference was found among the explants in response to plant hormones. The maximum percentage of callus induction (100%) was using the combinations of 1 BAP + 1 2, 4-D, 1 BAP + 1 NAA, and 1 BAP + 2 2,4-D mg. l-1. In addition, explants responses varied and the hypocotyls showed a superior result (85.71 %) as compared to other explants. For callus fresh weight, the combination of 0.22 TDZ + 79.9 Ad mg. l-1 had a significant effect, causing the highest fresh weight (0.2745g), while control treatment gave the lowest mean of 0.0066 g. Data showed that cotyledon explants were significantly superior in giving highest callus fresh weight with the mean of 0.1723 g. On the other hand, hypocotyl explants gave the lowest mean, reaching 0.1542 g.

Effects of shoot tip size on in vitro regeneration and virus elimination of grapevine cv. superior seedless

In this study, we investigate the relation between the explant size and the success of virus elimination in ‘Superior Seedless’ grape variety. Plants were tested by prior to thermotherapy and in vitro culture by using Double Antibody Sandwich-Enzyme-Linked Immunosorbent Assay (DAS-ELISA) and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and verified as infected by different viruses (Grapevine leafroll associated virus -1+3, Grapevine leafroll associated virus -4 Strains, Grapevine rupestris stem pitting associated virus). Different size of shoot tip explants (0.1-0.5-1-5-10 mm) were excised and cultured on MS medium supplemented with 1 mgl-1 BA. All of the explants bigger than 0.1 mm 100% regenerated while 70% of the 0.1 mm explants showed complete regeneration and turned into a whole plant. Plants regenerated from 10 mm shoot tip explants have all three viruses (GLRaV-1+3, GLRaV-4 strains and GRSPaV) as founded in mother plant. Plants regenerated from 5 mm explants have two of them (GLRaV-1+3, GLRaV-4 strains) and plants regenerated from 1 mm explants have one (GLRaV-1+3). Plants regenerated from 0.1 mm explants were found completely virus-free.

In Vitro Rapid Multiplication of a Highly Valuable Ornamental Aquatic Plant Anubias Heterophylla

The present study focuses on the development of a micropropagation protocol for true to type plants of Anubias heterophylla, a valuable ornamental aquatic plant. Natural propagation of aquatic species is limited due to the production of a small number of plants with a long cultivation period, disease and requirement of a large space for propagation. Surface-disinfected shoot tip explants were cultured on MS medium containing 0.1 % (w/v) activated charcoal (AC) and supplemented with 6-benzylaminopurine (BAP) at different concentrations (0, 1.0, 3.0 and 5.0 mg/L) either singly or in combination with alpha Naphthalene acetic acid (NAA) and 2,4-Dichlorophenoxy acetic acid (2,4-D) (0.5 and 1.0 mg/L). Among different auxins and cytokinin used, the number of shoots initiated per explant varied significantly among the different auxin and cytokinin combinations. The highest number of shoots per explants (3.60 ± 0.24) was formed in the culture medium containing 1.0 mg/L NAA in combination with 1.0 mg/L BAP, followed by in the culture medium with 3.0 mg/L BAP (2.40 ± 0.24). In the culture medium with 1.0 mg/L NAA and 1.0 mg/L BAP, 100 % of the cultured explants regenerated new shoots within 60 days. The maximum number of roots (19.80 ± 0.20 roots) per explant was observed after 60 days of culture on MS medium contained 0.1 % (w/v) AC and supplemented with 1.0 mg/L NAA and 1.0 mg/L BAP. With a 100% survival rate, the regenerated plantlets were effectively acclimatized to submerged underwater environments. Plantlets exhibited phenotypic traits that were comparable to those of their donor plant. This protocol is suited for commercial Anubias heterophylla propagation in the aquarium industry. HIGHLIGHTS The development of a micropropagation protocol for true to type plants of Anubias heterophylla The initiation of aseptic cultures of Anubias heterophylla from shoot tip explants Optimization of culture medium for shoot proliferation Rooting micro shoots and hardening of rooted micro shoots

A robust in-vitro protocol for shoot multiplication of Echinacea angustifolia

Echinacea angustifolia is an important medicinal and ornamental plant found in various regions of the world. This species may become threatened due to over-exploitation for medicinal uses. The present study was carried out to develop a rapid in vitro multiplication protocol using explants raised from seedlings. Complete plantlets have been successfully regenerated from shoot tip, leaf, petiole, stem, and root explants. The explants were incubated on Murashige and Skoog (MS) culture medium supplemented with different combinations of 6-benzyl amino purine (BAP) naphthalene acetic acid (NAA). Multiplication of shoot tips was achieved on BAP while from other explants; multiple shoots were regenerated on MS medium supplemented with BAP and NAA. The response of growth regulators was investigated. The shoot tip explants showed the highest rate of shoot induction (80%) and a shoot regenerated about 25 shoots per explants when cultured on MS media supplemented with BAP (4 µM) within 6–7 weeks. The leaf explants also developed shoots and each shoot generated 15 shoots in MS medium supplemented with BAP (5 µM) and NAA (5 µM). Shoot regeneration was also achieved with other explants mainly root, petiole, and stem on MS medium containing BAP (5 µM) + NAA (5 µM). The multiple elongated shoots were obtained on MS basal medium. Well-developed roots were achieved on MS medium in combination with BAP and NAA and 80% of plantlets were survived in the soil successfully in the hardening process. A robust and optimized protocol will be helpful for the mass production of this medicinal plant.

A Novel and Efficient In Vitro Organogenesis Approach for Ajuga lupulina Maxim.

This work was aimed at establishing an effective approach for in vitro propagation of Ajuga lupulina Maxim, a medicinal and ornamental plant mainly found in eastern Xizang, in the western Sichuan region of China. We report an optimum response in the proliferation of axillary shoots from nodal segment explants (10.2 shoots/explant) on MS medium containing 3.0 mg L−1 of 6-benzyladenine (BA). When BA and TDZ individually or in combination with NAA were employed for adventitious shoot regeneration, shoots and embryo-like structures (ELSs) were noted in the callus from leaf explants. The maximum response of 26.4 shoots /explant (81.6%) and 12.0 ELSs/explant were ascertained on MS medium with 4.0 mg L−1 TDZ and 0.1 mg L−1 NAA. The leaf despite browning still demonstrated a high regeneration capacity. TDZ (2.0 mg L−1) and BA (2.0 mg L−1) along with NAA (0.01 mg L−1) were found to perform well for shoot regeneration via callus from shoot tip explants. The best for rooting was MS medium (half-strength) containing indole-3-butyric acid (IBA: 1.5 mg L−1) and (NAA: 0.5 mg L−1) with the maximum number of roots (25.8 per shoot) and the highest rooting frequency (81.71%). The survival of the plantlets in the greenhouse was 78.2% indicative of successful acclimatization. This work is the first report of a consistent, definitive, and unique protocol for A. lupulina regeneration, paving the way for the in vitro preservation of such significant genetic resources and also further allied systems based on such callus-based or embryo-based approaches.

Aloe vera L. (Asphodelaceae): Supplementation of in-vitro culture medium with Aloe vera gel for production of genetically stable plants

As in vitro culture environments can be mutagenic, it's challenging to produce true-to-true type plants from meristems. Therefore, the present study aimed to devlop an efficient protocol for micropropagation from shoot tip explants of medicinally important Aloe vera using different concentrations of A. vera leaf gel (AvG) as organic supplement to the culture media. Assessment of the genetic stability of A. vera in vitro multiplied plants compared to the donor plant is one of the most important pre-requisites especially before its use for commercial and medicinal purposes. For shoot multiplication, the highest number of axillary shoots recorded was 13.27 ±5.11 with an average length of 2.21 ±0.84 cm on M3 medium (MS + 0.2 mg L−1 of β-indole butyric acid (IBA) + 3 mg L−1 benzylamino-purine (BA) + 5% AvG). All three strength of MS medium (1, 1/2, 1/4) with different concentrations of AvG resulted in 100% root induction after 4 weeks of culture. All the rooted microshoots (100%) were successfully acclimatized. To provide a reliable conclusion on its nutritive supply to MS medium, the total phenolic (TPC), condensed tannins (TTC), flavonoid (TFC), and flavonol (TFlC) content as well as the antioxydant activity of AvG were investigated. TPC and TTC values were found to be 31.02 ± 0.46 μg gallic acid equivalent mg−1 of extract and 4.00 ± 0.96 μg catechin equivalent mg−1 of extract, respectively while TFC and TFlC were 13.58 ± 0.84 and 9.75 ± 0.58 μg rutin equivalent mg−1 of extract, respectively. The results of antioxydant activity of AvG following DPPH, FRAP and ABTS assays were equal to 12.50 ± 0.89; 49.59 ± 2.07 and 64.93 ± 3.23 µmol Trolox equivalent mg−1 of extract, respectively which may explain the positive role of AvG as supplement.The genetic stability of in vitro propagated A. vera plants was evaluated using 10 inter simple sequence repeat (ISSR), 10 start codon targeted (SCoT) and 10 simple sequence repeat (SSR) markers. Out of these, 5 ISSR, 3 SCoT and 6 SSR primers produced resolvable, reproducible and scorable bands. ISSR primers generated 32 amplification products ranging from 200 to 1040 bp in size with a mean number of 6.4 bands while SCoT primers generated 33 amplicons with an average of 11 bands in the range of 160–2410 bp. In the SSR products, 6 bands were observed, each primer produced one band ranging from 410 to 720 bp. All banding profiles were monomorphic proving that the stability of the micropropagated A. vera plants was maintained. This study proved the suitability of supplementing in vitro culture media with AvG to enhance direct regeneration through shoot tip explants of A. vera for large scale micropropagation applications.

Micropropagation of Hibiscus moscheutos L. \u2018Luna White\u2019: effect of growth regulators and explants on nuclear DNA content and ploidy stability of regenerants

Hibiscus moscheutos L., also known as hardy hibiscus, is valued for its medicinal and ornamental attributes. It is usually propagated via seeds or cuttings. The purpose of this investigation was to develop a dependable micropropagation for H. moscheutos ‘Luna White’. To that end, the effect of four explant types (leaf, root, node, shoot tip) and two growth regulators 6-benzylaminopurine (BA) and meta-Topolin (mT) (6-(3-hydroxybenzylamino) purine) on in vitro growth of H. moscheutos was investigated. Genetic stability of the in vitro grown plants was assessed using flow cytometry, and chromosome count was investigated. No shoots were obtained from leaf or root explants. An efficient protocol for micropropagation of H. moscheutos using two explant types, 2-node and shoot tip explants, and two cytokinins (BA and mT) capable of producing true-to-type regenerants was established. Both BA and mT can be used at 2 μM or 4 μM using either 2-node or shoot tip explants. No significant difference was found between the nuclear DNA contents of seed-derived and in vitro grown plants (P < 0.05). The mean 2C DNA and monoploid 1Cx-values of seed-derived plants were 3.25 ± 0.08 pg and 1.62 ± 0.04 pg, respectively, compared with 3.26 ± 0.06 pg and 1.63 ± 0.02 pg, respectively, for in vitro grown plants. The chromosome number of both seed-derived plants and regenerants was determined to be 2n = 2x = 38. The mature regenerants obtained were fertile and phenotypically similar to seed-derived plants.

Clonal propagation of Chrysanthemum morifolium ramat using various explants obtained from field grown plants

A reliable and rapid large scale micropropagation method has been established from the node, shoots tip and leaf explant of Chrysanthemum morifolium growing in field condition. Experiments were conducted to standardize the culture media with plant hormone for multiple shoot proliferation and rooting for obtaining plantlets with uniform characteristics like mother plant in terms of growth and habits. Different concentrations and combinations of auxins (IAA) and cytokinins (BAP, Kin) were used in MS for the above purpose. Maximum shoot regeneration was found in MS treated with 2.0 mg/l BAP both in node and shoot tip explants. In the above combination, nodal explants produced 16 initial shoots. Shoot tip explants produced 12 shoots and leaf segment produced 07 shoots. For in vitro rooting, different concentrations of IBA and NAA were used. Higher rooting percentage was recorded on MS fortified with 1.5 mg/l IBA. The rooted plantlets were hardened and successfully established in the soil. About 90% of the regenerated plantlets survived in the natural environment.

Colchicine (a high-priced alkaloid) accumulation and HPTLC quantification in different stages of in vitro developed tuber of Gloriosa superba L.

BackgroundGloriosa superba L. belongs to Colchicaceae, which is an important medicinal plant containing high-priced alkaloid colchicines and other potent phytochemicals. Due to its extensive importance at the industrial level, this plant is overexploited. Moreover, indiscriminate harvesting for raw material leads to a decline in the population of this plant in the natural environment. Thus, the present study deals with the optimization of colchicine accumulation from the different intervals of in vitro and in vivo tubers of Gloriosa.ResultTo obtain in vitro tuberization, shoot tip explants were inoculated on Murashige and Skoog medium prepared with 3 mg/l BA and 0.5 mg/l Kn + 1 mg/l 2, 4-D followed by 2 mg/l BA + 0.2 mg/l NAA. In the high-performance thin-layer chromatography study (HPTLC), the linearity range of colchicine was set at a concentration range of 100–1000 ng/spot with a regression value (r) of 0.99. Its Rf value (0.25) was recorded at 254 nm. The colchicine amount in the in vivo tuber was 7.75 ± 0.25% dry weight, while the nearby amount of 7.7 ± 0.40% dry weight of colchicine was produced from 2 weeks in vitro old tuber. This value was followed by the 4th-week old tuber with 6.35 ± 0.17% dry weight and then a gradual decrease in its accumulation.ConclusionThe significant results for the accumulation of colchicine at different stages were observed. Hence, this strategy of colchicine production creates a new possibility for improved production of colchicine under in vitro conditions which will be helpful to various pharmaceutical industries without damaging the plants from the natural environment.Graphical abstract

Development of direct regeneration protocol for mass multiplication of Musa spp. variety Udhayam (Pisang Awak, ABB) using different explants

Musa spp. variety Udhayam (Pisang Awak, ABB) is the first high yielding selection from ICAR-NRCB, Trichy released during 2005. The demand for quality planting material shows an increasing trend because of its higher yield (40%) than the local Karpuravalli. But this variety is highly recalcitrant for shoot tip culture owing to its high phenolic exudation, and very low shoot proliferation rate (<2.0). Therefore, in the present study, attempts were made to develop direct regeneration protocol for the aforementioned variety using various explants like cormlets and male floral hands other than shoot tips. Results revealed that the direct regeneration protocols using cormlets and male floral hands were totally free from latent contamination and recorded high rate of shoot multiplication as against shoot tip explants. Among the three explants used, immature male floral hands showed not only higher multiplication rate under in vitro conditions and also performed better under field conditions compared to shoot tip and cormlet derived plants. The plantlets derived from different explants were found to be true to type as confirmed using ISSR markers. Field performance of the plants derived from various explants indicated that though all are suitable for direct regeneration, male floral hands was superior followed by sucker, shoot tip and cormlets in terms of bunch yield and crop duration. Key message: Immature male flower buds are the best explants for mass multiplication through direct regeneration and commercial exploitation in banana variety Udhayam (Pisang Awak, ABB).