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 seedlings germinated in cytokinin containing medium. Seeds germinated in thidiazuron (TDZ) at 0.5 mg l(-1) supplemented MS medium produced approximate to 11 axillary shoots/cotyledonary node. Stem and petiole explants derived from these axillary-shoots produced callus along with shoot-buds after 2 weeks of culture on half strength MS supplemented with 0.1 mg l(-1) alpha-napthaleneacetic acid. Shoot-buds were also produced from various sites of injury caused by incisions on the stem explants. Full strength MS salts inhibited bud formation. Histological studies indicated the differentiation of shoot-buds from the cortical cells. The pH of the regeneration medium had a significant effect on regeneration efficiency. The shoot-buds elongated and rooted on one third strength MS medium. The plantlets were transferred to soil after 3 weeks and 90-95% of the plantlets thus obtained could survive transfer to soil. The regeneration protocol described is highly reproducible and equally effective for all the four genotypes tested, viz. T-9, Pusa-1, Pusa-2 and PS-1 yielding about 5 shoot-buds/stem explant (with apex). The 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) 1998 Elsevier Science Ireland Ltd. All rights reserved.