IN-VITRO ADVENTITIOUS SHOOT REGENERATION FOR EFFECTIVE MAINTENANCE OFMALE-STERILE NIGER (GUIZOTIA-ABYSSINICA (L-F) CASS)

A rapid and efficient method of in vitro plant regeneration for large scale propagation of male sterile plants of niger (Guizotia abyssinica ) was developed. Leaf segments from mature plants were cultured on Mur ashige & Skoog's basal medium (MS) supplemented with N-6-benzyladenine (BA) and kinetin individually and in combination with low concentrati ons of indole-3-butyric acid (IBA); and alpha-Naphthaleneacetic acid ( NAA). Prolific direct adventitious shoot regeneration occurred on most of the media tested. The best response in terms of frequency of shoot regeneration and the number of shoots per leaf explant was observed o n medium supplemented with 2.22 mu M BA. Transfer of shoot bud cluster s to fresh medium with same composition promoted further multiplicatio n of the shoot buds, while medium with reduced BA concentration (0.89 mu M) facilitated shoot elongation. Shoots that were rooted on half-st rength MS medium gelled with 0.2 or 0.4% agar and supplemented with 4. 9 mu M IBA survived with a frequency of 61.36% on transfer to ex vitru m conditions. Field evaluation of the regenerants revealed the genetic stability of the plantlets and are being used in breeding of experime ntal hybrids.