In vitro manipulation and propagation of medicinal plants

The present review focuses on the various Ocimum species, often referred to as the “king of the herbs.” The botany of more than 50 species of herbs and shrubs belonging to this genus is thoroughly reported, along with traditional uses and cultivation techniques. Since basil is a rich source of natural compounds, details on the several chemical constituents of essential oil, plant parts and derived food and medical products, such as monoterpenes, sesquiterpenes, phenylpropanoids, anthocyanins, and phenolic acids, as well as their effect on sensory qualities are included. Furthermore, particular emphasis is given to the application of biotechnology for the clonal micropropagation of basil lines with improved traits and the use of basil tissue culture for the derivation of valuable compounds, such as antioxidant phenolics and essential oil components.

Ocimum sp. (Basil): Botany, Cultivation, Pharmaceutical Properties, and Biotechnology

The encapsulation technology in fruit plants--a review.

A mass in vitro propagation system for Bacopa monniera (L) Wettst (Scrophulariaceae), a medicinally important plant, has been developed A range of cytokinins have been investigated for multiple shoot induction with node, internode and leaf explants Of the four cytokinins (6-benzyladenine, thidiazuron, kinetin and 2-isopentenyladenine) tested thidiazuron (68 μM) and 6-benzyladenine (89 μM) proved superior to other treatments Optimum adventitious shoot buds induction occurred at 68 μM thidiazuron where an average of 93 shoot buds were produced in leaf explants after 7 weeks of incubation However, subculture of leaf explants on medium containing 22 μM benzyladenine yielded a higher number (1291) of adventitious shoot buds by the end of third subculture The percentage shoot multiplication (100%) as well as the number of shoots per explant remained the high during the first 3 subculture cycles, facilitating their simultaneous harvest for rooting In vitro derived shoots were elongated on growth regulator-free MS medium and exhibited better rooting response on medium containing 49 μM IBA After a hardening phase of 3 weeks, there was an almost 100% transplantation success in the field

Comparative studies of cytokinins on in vitro propagation of Bacopa monniera

A protocol is described for rapid and large-scale propagation of the woody aromatic and medicinal shrub Vitex negundo by in vitro culture of nodal segments from mature plants. Of the three different cytokinins – N6-benzyladenine (BA), kinetin, and thidiazuron – evaluated as supplements to Murashige and Skoog (MS) medium, BA at an optimal concentration of 2.0 mg/l was most effective in inducing bud break. Although callus-free multiple-shoot formation was a function of cytokinin activity alone, faster bud break coupled with an enhanced frequency of shoot development (92%) and internode elongation were dependent on the synergistic influence of gibberellic acid (GA3) when used at an optimal concentration (0.4 mg/l) along with BA (2.0 mg/l). The frequency of shoot proliferation was markedly influenced by the explanting season. By repeated subculturing of nodal segments harvested from the in vitro-formed axenic shoots on MS containing 1.0 mg/l BA and 0.4 mg/l GA3, prolific shoot cultures free from proximal callusing and showing a high-frequency multiplication rate were established. The percentage shoot multiplication (98–100%) as well as the number of shoots per node (six to eight) were highest during the first three culture passages, after which there was a gradual decline in shoot development. Rooting was best induced (94%) in shoots excised from proliferated shoot cultures on half-strength MS medium augmented with an optimal combination of indole-3-acetic acid and indole-3-butyric acid each at 1.0 mg/l. Vermi-compost was the most suitable planting substrate for hardening inside a plant growth chamber and its use ensured high-frequency survival (93%) of regenerated plants prior to outdoor transfer. Micropropagated plants established in garden soil were uniform and identical to the donor plant with respect to growth characteristics as well as vegetative and floral morphology.

Micropropagation of Vitex negundo L., a woody aromatic medicinal shrub, through high-frequency axillary shoot proliferation.

An efficient protocol for in vitro propagation of an aromatic and medicinal herb Ocimum basilicum L. (sweet basil) through axillary shoot proliferation from nodal explants, collected from field-grown plants, is described. High frequency bud break and maximum number of axillary shoot formation was induced in the nodal explants on Murashige and Skoog (1962) medium (MS) containing N6-benzyladenine (BA). The nodal explants required the presence of BA at a higher concentration (1.0 mg·l−1, 4.4 µM) at the initial stage of bud break; however, further growth and proliferation required transfer to a medium containing BA at a relatively low concentration (0.25 mg·gl−1, 1.1 µM). Gibberellic (GA3) at 0.4 mg·l−1 (1.2 µM) added to the medium along with BA (1.0 mg·l−1, 4.4 µM) markedly enhanced the frequency of bud break. The shoot clumps that were maintained on the proliferating medium for longer durations, developed inflorescences and flowered in vitro. The shoots formed in vitro were rooted on half-strength MS supplemented with 1.0 mg·l−1 (5.0 µM) indole-3-butyric acid (IBA). Rooted plantlets were successfully acclimated in vermi-compost inside a growth chamber and eventually established in soil. All regenerated plants were identical to the donor plants with respect to vegetative and floral morphology.

In vitro clonal propagation of an aromatic medicinal herb Ocimum basilicum L. (sweet basil) by axillary shoot proliferation

Efficient plant retrieval from alginate-encapsulated vegetative buds of mature mulberry trees

High frequency bud break and multiple shoots were induced in nodal explants collected between November to February from a 5 year old tree of Morus australis Poir syn. M. acidosa Griff. on Murashige and Skoog's medium supplemented with 6-benzylaminopurine (1.0 mg/1). Incorporation of gibberellic acid (0.3 mg/l) along with BAP (1.0 mg/l) not only induced faster bud break from nodal explants as well as from apical shoot buds, but it also enhanced the frequency of bud break. Nodal explants were more responsive than apical shoot buds. The shoots formed in vitro were multiplied further as nodal segments, and an average multiplication rate of 6-fold per subculture was established within 4–5 months. The shoots were successfully rooted on half-strength MS containing a combination of indole-3-acetic acid, indole-3-butyric acid and indole-3-propionic acid, each at 1.0 mg/1. The plantlets were successfully hardened off and established in natural soil.

Y. Sahoo

Papers

Micropropagation of Vitex negundo L., a woody aromatic medicinal shrub, through high-frequency axillary shoot proliferation.

In vitro clonal propagation of an aromatic medicinal herb Ocimum basilicum L. (sweet basil) by axillary shoot proliferation

Efficient plant retrieval from alginate-encapsulated vegetative buds of mature mulberry trees

Micropropagation of a fruit tree, Morus australis Poir. syn. M. acidosa Griff.

Plant regeneration from callus cultures of Morus indica L. derived from seedlings and mature plants