RESUMO
High temperature stress during pod filling severely affects the yield of Brassica juncea. Early flowering can evade the terminal heat stress and result in early maturity of the crop. In this study, a regeneration and transformation protocol has been standardized for B. juncea cv. Geeta. Hypocotyl from 5-day-old seedlings were used as explants. Of the various combinations of auxins and cytokinins tried along with Murashige and Skoog's (Physiol Plant 15:473-497, 1962) medium, MS + IAA (0.2 mg/l) + BA (3 mg/l) proved best for shoot regeneration with 89.9 % regeneration efficiency. To induce early flowering Leafy gene from Arabidopsis thaliana was transformed using Agrobacterium mediated transformation method. After 12 weeks transgenic plants showed flowering in vitro whereas their untransformed counterpart did not flower even after 16 weeks. The maximum transformation frequency was 4 %.