AN EFFICIENT REGENERATION SYSTEM OF BLACK GRAM (VIGNA-MUNGO L.) THROUGH ORGANOGENESIS

Regeneration has been achieved in Vigna mungo L. through organogenesis using explants from axillary shoots originating from the nodes of see dlings germinated in cytokinin containing medium. Seeds germinated in thidiazuron (TDZ) at 0.5 mg l(-1) supplemented MS medium produced appr oximate to 11 axillary shoots/cotyledonary node. Stem and petiole expl ants derived from these axillary-shoots produced callus along with sho ot-buds after 2 weeks of culture on half strength MS supplemented with 0.1 mg l(-1) alpha-napthaleneacetic acid. Shoot-buds were also produc ed from various sites of injury caused by incisions on the stem explan ts. Full strength MS salts inhibited bud formation. Histological studi es indicated the differentiation of shoot-buds from the cortical cells . The pH of the regeneration medium had a significant effect on regene ration efficiency. The shoot-buds elongated and rooted on one third st rength MS medium. The plantlets were transferred to soil after 3 weeks and 90-95% of the plantlets thus obtained could survive transfer to s oil. The regeneration protocol described is highly reproducible and eq ually effective for all the four genotypes tested, viz. T-9, Pusa-1, P usa-2 and PS-1 yielding about 5 shoot-buds/stem explant (with apex). T he regeneration system is efficient as it results in the recovery of 4 -5 plants within a period of 8 weeks, starting from an explant. (C) 19 98 Elsevier Science Ireland Ltd. All rights reserved.