REGENERATION OF THE TROPICAL LEGUME AESCHYNOMENE SENSITIVA SW FROM ROOT EXPLANTS

Regeneration of Aeschynomene sensitiva Sw. after callogenesis was obta ined from small (2-5 mm long) root explants of 30-day-old seedlings as eptically cultivated on Murashige and Skoog medium supplemented with v arious concentrations of growth regulators. After 4 weeks, the best re sults were observed with 0.54 mu M alpha-naphthaleneacetic acid and 2. 22 mu M benzyladenine. On this medium, the rate of regeneration depend ed on seedling age and agar concentration. The highest number of shoot s per explant was obtained with small cuttings from 30-day-old seedlin gs grown on a medium containing 8 g 1(-1) of agar. Regeneration succes s was also dependent on explant size. When longer explants (7-20 mm) w ere cut from the main root, direct regeneration was obtained in two we eks. These cuttings also generated shoots through callogenesis in four weeks but always in lower quantities than with direct regeneration, w hatever the seedling age. Here also, the best regeneration was obtaine d with cuttings from 30-day-old seedlings maintained on a medium with 8 g 1(-1) of agar. Regenerants were rooted on growth-regulator-free Mu rashige and Skoog medium and then acclimatized in a greenhouse. A bett er survival to transplantation was observed when plantlets were inocul ated with the photosynthetic Bradyrhizobium strain ORS 278. Stem and r oot nodules developed on the inoculated plantlets and were able to fix nitrogen.