Explants For Micropropagation Research Articles

Micropropagation of Pogostemon paniculatus

Plant regeneration potential from node & leaf explants of Pogostemon paniculatus through direct shoot proliferation was studied on Murashige and Skoog medium supplemented with various concentrations of cytokinins & auxins. As the seed germinability of the plant is low in vitro, we have tried these explants for micropropagation. Among different concentrations of individual hormones tested for nodal explants, benzylaminopurine (BAP) at 5µM & kinetin (Kn) at 0.5µM showed 4 & 2 mean number of shoots/explant respectively & combination of Kn (0.5 µM) + BAP (1.5 µM) showed 15 mean number of shoots/explant. For leaf explant combination of Kn (0.5 µM) + BAP (1.5 µM) showed 20 mean number of shoots/explant. Other hormones tested at all concentrations showed callus formation without the shoot development. Roots were established on the isolated shoots on naphthaleneacetic acid (NAA) at 0.25µM. Rooted plants were acclimatized. This is the first report of Pogostemon paniculatus micropropagation.

In Vitro Propagation of Aconitum chasmanthum Stapf Ex Holmes: An Endemic and Critically Endangered Plant Species of the Western Himalaya

Aconitum chasmanthum Stapf ex Holmes, a highly valued medicinal plant, is a critically endangered plant species with restricted global distribution. Because there is no published report on the in vitro micropropagation of A. chasmanthum, the present study was undertaken to contribute to the development of an efficient micropropagation protocol for its conservation. Seeds collected from the wild showed enhanced germination after being given a chilling treatment (−4 °C and −20 °C) for different durations (10, 20, 30 and 40 days). Seeds given a chilling treatment of −4 °C for 10 days showed enhanced germination rates of 47.59 ± 0.53% with a mean germination time of 10.78 ± 0.21 days compared to seeds kept at room temperature when grown in an MS basal medium. Nodes, leaves and stems, taken from 20–40-day-old seedlings, were used as an explant for micropropagation. An MS medium supplemented with different concentrations of cytokinins (BAP, Kn), auxins (2,4-D, NAA), and an additive adenine sulphate were tested for callusing, direct shoot regeneration and rooting. Only nodal explants responded and showed direct multiple shoot regeneration with 7 ± 0.36 shoots with an elongation of 5.51 ± 0.26 cm in the MS medium supplemented with BAP 0.5 mg/L, and with a response time (RT) of 10.41 ± 0.51 days and a percentage culture response of 77.77 ± 2.77%. Rhizome formation was observed after 8 weeks, with the highest culture response of 36.66 ± 3.33% in the MS basal media with an RT of 43.75 ± 0.50 days. These rhizomes showed a 60% germination rate within 2 weeks and developed into plantlets. The present in vitro regeneration protocol could be used for the large-scale propagation and conservation of A. chasmanthum.

Antioxidant Capacity of Origanum heracleoticum L. Flower and Leaf Extracts and Their Essential Oil Profiles of Plants from Micropropagation and Collection from Natural Habitats

The composition of the essential oils and the antioxidant properties of Origanum heracleoticum L. leaves and flowers collected from four different natural populations in Bulgaria (two locations in Kresna Gorge and two locations in Rhodopes Mountain) were studied and compared with those of micropropagated and field-adapted plants. Explants for micropropagation from wild-growing plants from Gorna Breznitsa (Kresna Gorge) were used. The enzyme antioxidant potential characterised by the activity of superoxide dismutase, catalase, guaiacol peroxidase, ascorbate peroxidase as well as the non-enzyme antioxidant potential characterized by the content of phenols, flavonoids, water- and lipid-soluble antioxidant metabolites, were affected by environmental conditions and type of propagation (wild or micro). The highest enzyme antioxidant potential was observed in the flowers and leaves of the micropropagated plants, followed by the plants collected from Gorna Breznitsa. The variation in the content of metabolites with antioxidant potential in the Greek oregano collected from the two locations from each two areas of Bulgaria was detected. The higher content of phenols and flavonoids was detected in micropropagated plants as well as in wild-plants collected from two localities from Kresna Gorge, when compared with the wild-plants collected from Eastern Rhodopes. Forty-five compounds in the O. heracleoticum essential oil collected from the native populations were identified. Based on the essential oil composition, and especially on the carvacrol and thymol contents, the O. heracleoticum plants from all investigated natural populations in Bulgaria belonged to the carvacrol chemotype. Besides environmental conditions, another factor that affected the composition of O. heracleoticum essential oil was the existence of chemotypes.

An improved micropropagation protocol for the recalcitrant plant Capsicum – a study with ten cultivars of Capsicum spp. (C. annuum, C. chinense, and C. frutescens) collected from diverse geographical regions of India and Mexico

ABSTRACTCapsicum spp. is a commercially important crop of the Solanaceae family, well-known for its multipurpose use as a vegetable, spice, medicinal and ornamental plants. The genus Capsicum is a recalcitrant species in terms of in vitro morphogenesis and plant regeneration. An efficient method was developed for multiple shoot regeneration in 10 cultivars of Capsicum collected from diverse geographical regions of India and Mexico. Seeds germinated in vitro on a half-strength Murashige and Skoog (MS) medium supplemented with 3.0 % sucrose. Nodes of the in vitro germinated seedlings were used as explant for micropropagation. The combination of the 6-benzylaminopurine, indole-3-acetic acid, and spermidine was found to be the best for multiple shoot induction. However, the optimum responcse varied accompanied by different cultivers with maximum 8.9 ± 0.52 (Capsi-10) to 15.3 ± 0.69 (Capsi-5) multiple shoot per explant. Depending on the cultivar, multiplied shoots were successfully rooted with maximum 18.4 ± 0.20 (highest for Capsi-9) to 36.8 ± 0.29 (highest for Capsi-5) roots per shoot on half-strength MS medium supplemented with 2.0 mg l−1 indole-3-butyric acid, 1.0 mg l−1 α-naphthalene acetic acid, and 1.5 mM spermidine. Finally, the micropropagated plantlets were acclimatized with 40.0–86.7 % survival rate, depending on different cultivars.

English

The present study includes two experiments; the physiological and the biotechnological experiments. The physiological experiment was designed to investigate the most interesting rare natural phenomenon of the development of vegetative reproductive organs (bulbils) in the inflorescence of tiger lily. In the other hand, the biotechnological experiment was carried out to evaluate the regeneration potential of bulbils culture in vitro. In the first experiment, the plants of tiger lily Lilium lancifolium var. Flore Pleno which were grown in greenhouse showed that the Pseudo viviparous phenomenon at the end of flowering when vegetative bulbils were induced in the inflorescence. These bulbils as pseudo viviparous structures were precisely formed in place of flowers and along the floral stalks. The flower head was completely surrounded by the extensive numbers of these bulbils; some of them continued in growth and produced new shoots. The tissue culture experiment of tiger lily var. Flore Pleno was carried out using bulbils culture for eight weeks of culture in vitro. The results indicate that the bulbils was shown to be a good choice as explants for micropropagation but the potential of these bulbils to produce  bulblets, shoots and roots was greatly influenced by the concentrations of naphthalene acetic acid (NAA) and  benzyl aminopurine (BA) in culture. However, the concentration of 1 mg/l BA combined with 0.1 mg/l NAA was shown to be the optimum for micropropagation of tiger lily var. Flore Pleno. Key words: Bulbils, pseudo viviparous phenomenon, tiger lily, in vitro, micropropagation, growth regulators.

Micropropagation of Bauhinia variegata L. from Tissue Culture

Bauhinia variegate L. is a multipurpose tree and its micropropagation holds great promise in agroforestry. The sterilized seeds were first inoculated on Murashige and Skoog (MS) medium. Nodal cuttings from these seedlings grown in vitro were used as explants for micropropagation. Nodal cutting inoculated on the medium with various concentrations of BAP (benzyl-aminopurine) and NAA (£- naphthalene acetic acid) and separately generated varied results. Best propagation was recorded on MS medium supplemented with 1.0 ?M BAP with 0.05 ?M NAA. Propagated plants were successfully acclimatized and rooted in pots (6 cm diameter) containing soil and sand in1:1 ratio and then finally transferred to the field. All the data generated were analysed statistically using SPSS statistical package. Nepal Journal of Science and Technology Vol. 13, No. 1 (2012) 39-41 DOI: http://dx.doi.org/10.3126/njst.v13i1.7397

Use of cactus flowers as explants for micropropagation

SummaryFlowers and floral parts have seldom been used successfully as explants to initiate tissue culture. Flower buds of Mammillaria albicoma, M. carmenae, and M. schiedeana (Cactaceae) were cultured on solid Murashige and Skoog medium containing 0.1 mg l−1 -naphthaleneacetic acid (NAA) and 5.0 mg l−1 6-benzylaminopurine. The formation of vegetative buds (areoles) and the development of shoots were observed in all three species. Both direct and indirect mechanisms of shoot morphogenesis were observed. Direct shoot morphogenesis from the perianth (especially from the axils of the perianth segments) in M. albicoma and M. carmenae was confirmed by microscopic examination. Shoots that formed on explants were isolated and used to establish proliferating cultures. Finally, proliferated shoots were rooted in vitro on MS medium containing 0.01 mg l−1 NAA and acclimated to ex vitro conditions. M. carmenae shoots were also rooted non-aseptically in horticultural substrate. This is the first report of the complete micropropagation of cacti initiated from floral explants. In this family of leafless stem succulents, harvesting of flowers may be a convenient way to micropropagate valuable genotypes, as it avoids injury to stock specimens.

Micropropagation of Astragalus Maximus Willd

ABSTRACTMicropropagation of Astragalus maximus Willd. through axillary bud culture was achieved 30 day-old plants. The shoots of plants were used as explants for micropropagation. The explants were cultured on MS media supplemented with BA (0.2, 0.5, 1.0 mg/l), ZR (0.2, 0.5, 1.0 mg/l) and their combinations with 0.4 mg/l NAA. After 20 days, micropropagation was strongly induced in MS medium supplemented with 0.5 mg/l ZR, ∼30 shoots obtained from each explant. In all other treatments, proliferation number on per explant varied to 2–3. Propagated shoots were cultured on MS medium without plant growth regulators, MS medium supplemented with 0.2–1.5 mg/l NAA and ½ MS with 1.5 % sucrose. Root induction was only achieved on ½ MS containing 1.5 % sucrose after 20 days. Plane MS and MS medium with 0.2, 0.4, 0.8, 1.2 and 1.5 mg/l NAA did not induce root formation.

Random amplified polymorphic DNA (RAPDs) markers for genetic analysis in micropropagated plants of Robinia pseudoacacia L.

Four years' old micropropagated plants regenerated by enhanced axillary branching from shoot buds of a single genotype of Robinia pseudoacacia were characterized by RAPDs. Random amplified polymorphic DNA analysis was carried outusing 19 random 10-mer DNA primers and 286 RAPD bands were examined which showed 30% polymorphism. Similarity indices ranged from 0.86 to 0.96 among different plants based on RAPD data. The UPGMA dendrogram was constructed based on similarity indices which showed clustering of different plants into subgroups based on similarity values. Our results suggest that somaclonal DNA sequence variations are present even when organized cultures such as shoot buds were used as explant for micro-propagation.