A. V. Raghu

Direct shoot organogenesis from leaf explants of Embelia ribes Burm. f. : a vulnerable medicinal plant

An efficient system was developed for direct plant regeneration from in vitro-derived leaf explants of Embelia ribes Burm. f., a vulnerable medicinal woody climber of the Western Ghats of India. The in vitro procedure involved three steps that included induction of shoot initials from leaf tissue, regeneration and elongation of shoots from the shoot initials, and rooting of shoots. The induction of shoot initials was achieved on Murashige and Skoog (MS) solid medium supplemented with different concentrations of thidiazuron (TDZ). The best medium for shoot induction was MS with 0.272 µM TDZ. Numerous shoot primordia developed within 2–3 weeks on the leaf margin as well as on the midrib region, without any callus phase. In the second step, the shoot clumps separated from the leaf explant on transfer to MS basal medium, resulting in the differentiation of 90% of the shoot initials into well-developed shoots. The 2- to 3-cm-long shoots rooted on half-strength MS basal medium supplemented with 4.90 µM indole-3-butyric acid (IBA) and 3% (w/v) sucrose in the third stage. The rooted plants could be established in soil with 70% success. This protocol could be utilized for in vitro propagation and conservation of this important threatened medicinal plant.

IN VITRO CLONAL PROPAGATION THROUGH MATURE NODES OF TINOSPORA CORDIFOLIA (WILLD.) HOOK. F. & THOMS.: AN IMPORTANT AYURVEDIC MEDICINAL PLANT

SummaryA protocol was developed for rapid clonal propagation of the important medicinal climber, Tinospora cordifolia, through in vitro culture of mature nodal explants. Shoots were initiated on both Murashige and Skoog (MS) medium and woody plant medium (WPM) supplemented with 2.32 μM kinetin (KIN). Of the two basal media tested, WPM was found to be superior to MS medium for the induction of multiple shoots. Among the cytokinins tested, N6-benzyladenine (BA) was more effective than KIN for axillary shoot proliferation. KIN was superior to BA in terms of shoot elongation. An average multiplication rate of 6.3 shoots per explant was obtained with WPM supplemented with 8.87 μM BA. Shoot clumps harvested from this medium were transferred to WPM supplemented with 2.22 μM BA and 4.65 μM KIN for shoot elongation. Elongated shoots were rooted in half-strength MS medium supplemented with 2.85 μM indole-3-acetic acid (IAA). Rooted plantlets were successfully transferred to sand and established with 80% survival.

An efficient micropropagation system for Celastrus paniculatus Willd.: a vulnerable medicinal plant

A micropropagation protocol was developed for Celastrus paniculatus, a vulnerable medicinal plant. Cultures were initiated from nodal explants collected from young shoots of a 12-year-old plant in MS basal medium. An average of five shoots were produced in MS medium supplemented with 1.5 mg l−1 benzyl adenine (BA) and 0.1 mg l−1 naphthalene acetic acid (NAA) after two subculture cycles with a 30-day interval. Continuous subculture in the same medium for three more cycles resulted in reduction of the number of multiple shoots (2 or 3 shoots), vitrification of the shoots, and callus formation. Vitrification of cultures could be overcome by the use of MS medium supplemented with lower concentrations of BA (0.05 mg l−1) and NAA (0.01 mg l−1). Among the various rooting trials, ex vitro rooting of shoots with simultaneous hardening was most efficient. The method standardized in the present study is simple, as it eliminated separate steps for in vitro rooting and hardening. Qualitative chemical similarity of the tissue culture regenerants with the mother plant was confirmed using high performance thin-layer chromatographic (HPTLC) profiling.

In Vitro Propagation of Two Tuberous Medicinal Plants: Holostemma ada-kodien and Ipomoea mauritiana

Medicinal plants are sources of important therapeutic aid for healing human diseases. The depletion of the wild resources has prompted conservation, propagation, and enhancement of resources for medicinal plants. Micropropagation offers an alternate method to propagate and improve medicinal plants through selection of high-yield lines and their efficient cloning. This chapter describes cost effective and efficient protocols that have been successfully applied for the micropropagation and large-scale production of quality planting material in two important tuberous medicinal plants viz., Holostemma ada-kodien Schult. and Ipomoea mauritiana Jacq.

Optimizing Culture Conditions for in vitro Propagation of Trichosanthes cucumerina L.: An Important Medicinal Plant

ABSTRACT A simple and efficient, single medium–based protocol for rapid in vitro propagation was developed for Trichosanthes cucumerina L., an important medicinal plant of the family Cucurbitaceae. The effects of culture vessel, medium quantity per vessel, and inoculation density were investigated, and optimum culture conditions for vigorous growth for large-scale propagation were standardized. Axillary bud proliferation coupled with rooting from nodal explants was obtained in MS medium supplemented with 0.46 μM kinetin and 2.46 μM indole 3-butyric acid. The highest culture response (97 %) and multiplication rate of 1:7 (seven shoots per explant for next subculture in 4 weeks) coupled with rooting was achieved in this medium. Inoculation density of five nodes per culture bottle containing 30 ml of the medium was the optimum. Rooted plantlets could be established in sand with an average of 90% survival. The micropropagated plants exhibited morphological similarity with the mother plants. The results indicate the key culture conditions can be regulated to improve the multiplication rate and quality of planting material.