AN EFFICIENT IN VITRO MULTIPLE SHOOTING METHOD OF STEVIA REBAUDIANA BERTONI.

The small miracle plant Stevia rebaudiana Bert. is commercially important due to presence of a natural sweetner, stevioside (diterpene glycoside), a potent alternative to sucrose. Poor seed germinability limits its reproduction to only vegetative propagation by stem cuttings. This makes micropopagation most reliable method. Axenically grown cotyledonary leaves produce profuse calli (10mg/lit NAA-0.5mg/lit Kinetin), which subsequently develop microshoots. Vigorous microshooting (max 72.65, microshoots/explant) was noticed at moderate concentrations of Kinetin and BA (Kinetin 3mg/lit- 5mg/lit, BA 0.5mg/lit-3mg/lit) with maximum shoot length in minimum shoot initiation time. Most of such microshoots rooted efficiently (20 roots /shoot; 4cm root length) within 5-6 days of culture at high IBA concentrations (5mg/lit- 10mg/lit). Such efficient microshoots are being tested for their acclimatization and field establishment potential through routine hardening procedures. The objective of the study is to develop an elite line (microshoots) with high regeneration, good field transfer potential with sustained stevioside production.