In vitro regeneration through adventitious buds in Wattakaka volubilis, a rare medicinal plant

High frequency shoot regeneration from in vitro derived leaf explants of Wattakaka volubilis (L.f.) Stapf was achieved through callus mediated organogenesis. Organogenic calli were induced from 20 day old aseptic seedling explants on Murashige and Skoog medium fortified with various concentrations and combinations of plant growth regulators, benzylaminopurine (BAP), α-naphthaleneacetic acid (NAA), indole 3-butyric acid (IBA) and gibberellic acid (GA3). A mean of 8.6 shoots developed from organogenic callus induced from a 2 x 2 cm leaf explants on MS medium with 3% sucrose having 5.37μM NAA in combination with 2.22 μM BAP with 60% induction capacity. Further development of adventitious shoots could be achieved by sub culturing the callus to the same medium with 4.40 μM BAP and 0.288 μM GA3. Organogenesis could not be achieved from the calli of ex vitro derived leaf explants. The developed shoots were rooted on half-strength MS medium with 1% sucrose, 4.90 μM IBA and 0.93 μM kinetin at a frequency of 85%. Well rooted plantlets were then transplanted to vermiculite soil (3:1) mixture in polythene covered pots kept under culture room conditions. Approximately 60% plantlets survived and grew into whole plants.Keywords: Adventitious shoots, caulogenesis, organogenic callus-histologyAfrican Journal of Biotechnology, Vol. 13(1), pp. 55-60, 1 January, 201

In vitro conservation of Ceropegia elegans, an endemic plant of South India

The purpose of this study was to develop in vitro techniques for conserving endemic species, Ceropegia elegans by axillary shoot multiplication. Murashige and Skoog (MS) medium with kinetin (Kn) 23.20 μM + indole-3-acetic acid (IAA) 5.71 μM was the best for axillary bud proliferation inducing a mean of 7.11 ± 0.07 shoots per node. Shoots developed were rooted best on half strength MS medium with 4.90 μM indole-3-butyric acid (IBA). Plantlets established in pots exhibited 72% survival rate.Keywords: Ceropegia elegans, endemic species, micropropagatio

Plant regeneration from leaf-derived callus in Plectranthus barbatus Andr. [Syn.: Coleus forskohlii (Wild.) Briq.]

A protocol was developed for Plectranthus barbatus for high frequency shoot organogenesis from leaf derived callus of aseptically grown plantlets derived from mature plant explants of high yielding clones (yield of forskolin 1.5 to 1.9%) on Gamborg medium (B5) medium supplemented with 2 mg/l 2,4- dichloro phenoxy acetic acid (2,4-D). Shoots were regenerated from the callus on MS medium supplemented with 6-benzyl amino purine (BAP) (2 mg/l) + naphthalene acetic acid (NAA) (1 mg/l). The highest rate of shoot multiplication was achieved at the 6th subculture and more than 2000 shoots were produced from callus clump. Roots were induced from shoots of in vitro grown plantlets on basal half strength MS medium and high rooting frequencies were obtained. Regenerated plants were easily acclimatized in greenhouse conditions and later transferred to soil with 100% survival. The procedure here allows the micropropagation of P. barbatus in five months of culture and proliferated cell masses which could be used for studies of organic compounds of pharmaceutical interest.Keywords: Callus culture, medicinal plant, root induction, shoot organogenesisAfrican Journal of Biotechnology Vol. 12(18), pp. 2441-244

Effect of medium, explants, cytokinins and node position on in vitro shoot multiplication of Caralluma lasiantha (Wight) N.E.Br., an endemic and medicinally important plant

An efficient shoot multiplication protocol was developed for Caralluma lasiantha, an endemic medicinal plant belonging to the family Asclepiadaceae. Mature explants were cultured on Murashige and Skoog (MS), (1962) medium, Gamborg's B5 (B5) and woody plant medium (WPM) supplemented with 6-benzyladenine (BA), 8.87 µM, for shoot induction. The nodal explants exhibited maximum shoot sprouting frequency when cultured on MS medium supplemented with BA (8.87 µM). Nodal explants cultured on MS medium supplemented with different concentrations of cytokinins with 3% sucrose exhibited 100% sprouting frequency. Maximum number of three to four shoots was induced from mature second nodal explants on MS medium containing BA (8.87 µM). The isolated microshoots were rooted on half strength MS medium supplemented with naphthalene acetic acid (NAA), 0.54 µM. The plantlets thus developed were hardened and successfully established in soil.Key words: 6-Benzyl adenine, nodal explant, naphthalene acetic acid, Caralluma lasiantha, micro  propagation

Synthetic seeds: A review in agriculture and forestry

Production of synthetic seeds has unraveled new vistas in in vitro plant propagation technology, because it offers many useful advantages on a commercial scale for the propagation of a variety of crop plants. These tools provide methods for production of synthetic seeds for conversion into plantlets under in vitro and in vivo conditions. This technology is useful for multiplying and conserving the elite agricultural and endangered medicinal plant species, which are difficult to regenerate through conventional methods and natural seeds. The synthetic seed technology was developed in different economically important plant species such as vegetable crops, forage legumes, industrially important crops, cereals, spices, plantation crops, fruit crops, ornamental plants, orchids, medicinal plants and wood yielding forest trees etc. All these aspects are presented in this review.Key words: Synthetic seeds, in vitro, in vivo plant propagation

In vitro shoot multiplication and conservation of Caralluma bhupenderiana Sarkaria - an endangered medicinal plant from South India

An efficient protocol was described for the rapid in vitro multiplication of an endangered medicinal plant, Caralluma bhupenderiana Sarkaria, via enhanced axillary bud proliferation from nodal explants collected from young shoots of six-months-old plant. The physiological effects of growth regulators [6- Benzyladenine (BA), kinetin (Kn), 2-Isopentyl adenine (2iP), zeatin (Zn), indole-3-acetic acid (IAA), indole-3-butyric acid (IBA)], different strengths of Murashige and Skoog (MS) medium and various pH levels on in vitro morphogenesis were investigated. The highest number (8.40 + 0.50) of shoots and the maximum average shoot length (3.2 ± 0.31 cm) were recorded on MS medium supplemented with BA (8.87 μM) at pH 5.8. Rooting was best achieved on half-strength MS medium augmented with NAA (2.69 μM). The plantlets regenerated in vitro with well-developed shoot and roots were successfully established in pots containing peat mass and garden manure in 1:1 ratio and grown in a greenhouse with 80% survival rate. The regenerated plants did not show any immediate detectable phenotypic variation.Key words: Apocynaceae, asclepiadoideae, conservation, micro-propagation, endangered, Caralluma bhupenderiana

Effect of Hormones on the Organogenesis and the Somatic Embryogenesis of an Endangered Tropical Forest Tree - Hildegardia populifolia (Roxb.) Schott. & Endl.

Nodal explants from aseptic seedlings of Hildergardia populifolia cultured on Murashige and Skoog’s (MS) medium supplemented with 2 mgL-1 N6-benzylaminopurine (BAP) generated very few shoots over a period of 30 days. Shoots were rooted in vitro on 1/2 strength MS macro salts containing 2 mgL-1 naphthalene acetic acid (NAA). A significant achievement in the present investigation was the production of somatic embryos from immature zygotic embryo explants exposed to MS medium supplemented with NAA 3 mgL-1 and casein hydrolysate (CH) 1000 mgL-1 over a period of 60 days. Subsequent withdrawl of NAA and CH from the medium resulted in the maturation and growth of embryos into plantlets on MS medium. The plantlets were transferred to sand: manure: soil mixture (1:1:1) where they showed no visual abnormalities in morphological characters

Shoot Regeneration from Hypocotyl and Shoot Tip Explants of Sterculia foetida L. Derived from Seedlings

Hypocotyl and shoot tip explants derived from the seedlings of Sterculia foetida were placed on MS medium supplemented with various cytokinin and auxin combinations. Cytokinin-like N6-benzylaminopurine (BAP), kinetin (KN), thidiazuron (TDZ) and auxin-like indole acetic acid (IAA), naphthalene acetic acid (NAA) and indole butyric acid (IBA) were supplemented either individually or in combinations. The regenerated shoots were separated and placed on the rooting medium augmented with different auxin-like IAA, IBA and NAA (0.1-2 mgL-1). IAA (2 mgL-1) induced 3-4 roots from the cut end of the micro shoots. Rooted plantlets were acclimatized to field conditions by placing them in pots containing sterilized sand, soil and manure mixture (1:1:1) and subsequently transferred to field with 40% survival