B. V. Ravishankar

Bio: B. V. Ravishankar is an academic researcher from Karnatak University. The author has contributed to research in topics: Guizotia & Rhizome. The author has an hindex of 4, co-authored 4 publications receiving 104 citations.

In vitro propagation of the endangered orchid, Geodorum densiflorum (Lam.) Schltr. through rhizome section culture

Abstract: Micropropagation of the endangered terrestrial orchid, Geodorum densiflorum (Lam.) Schltr. was achieved through rhizome section culture from in vitro seed- derived rhizomes. Rhizome sections were cultured on Murashige and Skoog (MS) and Knudson C(KC) media supplemented with various growth regulators and 0.1% activated charcoal. The rhizome sections responded on MS medium. Naphthaleneacetic acid (NAA) at 2.0 μM stimulated rhizome growth. However, benzyladenine (BA) at 5.0 μM induced multiple shoots within four weeks of culture and inhibited rhizome growth. The regenerated shoots rooted on MS only or with NAA at 1.0 μM. Well-developed plantlets were transferred to community pots and then to a greenhouse where the plants have been acclimatised.

The Influence of Polyamines on Androgenesis of Cucumis sativus L.

Abstract: Summary The influence of polyamines (putrescine and spermidine; 5–1000 µM) was studied on androgenesis of Cucumis sativus L. cvs ‘Calypso’ and ‘Green Long’. Addition of polyamines (putrescine or spermidine; 5–200 µM) to the embryo induction medium [B5 (GAMBORG et al. 1968) containing 2.0 µM 2,4-dichlorophenoxyacetic acid (2,4-D), 1.0 µM 6-benzyladenine (BA) and 0.25 M sucrose] enhances the rate of embryogenesis and spermidine showed optimum response (90.66 and 100.33 embryos per 60 anthers of ‘Calypso’ and ‘Green Long’ respectively) at 200 µM. Higher concentrations (500 or 1000 µM) of putrescine and spermidine were not beneficial for embryogenesis. Embryo differentiation was achieved on B5 medium supplemented with 0.25 µM of α-naphthaleneacetic acid (NAA), 0.25 µM kinetin (Kn) and 0.09 M sucrose. Transfer of the differentiated embryos to maturation medium containing 0.09 M sucrose and 10 µM abscisic acid (ABA) resulted in maturation of embryos. Mature embryos developed into plantlets on germination medium containing 0.09 M sucrose. Embryos developed from anthers on induction medium containing 200 µM spermidine showed maximum regeneration efficiency.

Direct somatic embryogenesis and plantlet regeneration from leaf explants of niger, Guizotia abyssinica (L.f.) Cass.

Abstract: Somatic embryogenesis was induced in niger (Guizotia abyssinica (Lf) Cass) using a simple one step method Leaf explants were cultured on MS medium with 2,4-D and BAP/Kn individually and in combination Somatic embryogenesis occurred directly without an intervening callus proliferation phase from subepidermal regions of leaf explants on MS medium supplemented with 2,4-D (20 and 50 microM) plus Kn/BAP (10 and 20 microM) Regenerated somatic embryos were successfully grown into whole plants

Anther culture for haploid and doubled haploid production

Abstract: Haploids are plants with a gametophytic chromosome number and doubled haploids are haploids that have undergone chromosome duplication. The production of haploids and doubled haploids (DHs) through gametic embryogenesis allows a single-step development of complete homozygous lines from heterozygous parents, shortening the time required to produce homozygous plants in comparison with the conventional breeding methods that employ several generations of selfing. The production of haploids and DHs provides a particularly attractive biotechnological tool, and the development of haploidy technology and protocols to produce homozygous plants has had a significant impact on agricultural systems. Nowadays, these biotechnologies represent an integral part of the breeding programmes of many agronomically important crops. There are several available methods to obtain haploids and DHs, of which in vitro anther or isolated microspore culture are the most effective and widely used. This review article deals with the current status of knowledge on the production of haploids and DHs through pollen embryogenesis and, in particular, anther culture.

The Application of Biotechnology to Orchids

Abstract: This review provides an informative and broad overview of orchid biotechnology, addressing several important aspects such as molecular systematics, modern breeding, in vitro morphogenesis, protoplast culture, flowering control, flower color, somaclonal variation, orchid mycorrhiza, pathogen resistance, virus diagnosis and production of virus-free plants, functional genomics, genetic transformation, conservation biotechnology and pharmaceutical biotechnology. This resource will provide valuable insight to researchers who are involved in orchid biology and floriculture, using biotechnology to advance research objectives. Producing an improved orchid through biotechnology for industrial purposes or to serve as a model plant for pure and applied sciences is well within reach and many of the current techniques and systems are already employed at the commercial production level.

Protocorm-like body (PLB) formation and plant regeneration from the callus culture of Dendrobium candidum Wall ex Lindl

Abstract: An efficient system was established for a higher frequency of protocorm-like body (PLB) formation from the callus of Dendrobium candidum Wall ex Lindl. The calluses were induced from longitudinally bisected segments of protocorms and subcultured two times every 40d on Murashige and Skoog medium with macronutrients at half strength, micronutrients at full strength, 2% sucrose, and with 8.8μM 6-Benzylaminopurine. PLB formation was achieved when calluses were transferred onto the same basal medium without any plant growth regulators. PLBs developed into intact plantlets about 2cm in height and with four roots when on basal medium with 2.7μM 1-naphthaleneacetic acid. Plantlets were transplanted into vermiculite with a 95% survival rate in a greenhouse. Histological observations proved that globular somatic embryos could be produced from the inside and surface of the embryogenic callus during PLB formation.