High frequency plant regeneration from embryogenic callus of a popular indica rice (Oryza sativa L.).

The aim of the study is to establish a routine procedure for high frequency plant regeneration from in vitro raised embryogenic callus of abiotic salt sensitive indica rice (Oryza sativa L.) cultivar ADT 43. The effect of synthetic auxin 2,4-D on callus induction was optimized to achieve high frequency plant regeneration from fresh embryogenic callus without further subculture. Friable, nodular and creamish-white embryogenic callus cultures were raised from mature rice seeds on LS medium supplemented with 2.5 mg L(-1) 2,4-D and 1.0 mg L(-1) thiamine-HCL. Plant regeneration was achieved by the 24 days old embryogenic callus on MS medium supplemented with 1.0 mg L(-1) BAP and 1.5 mg L(-1)NAA. In vitro regenerated plants with multiple tillers and roots were transferred to sterile soil and maintained in the growth chamber. The regenerated plants exhibited normal growth and were phenotypically similar to plants maintained in the garden. Using the present protocol, 25-30 plantlets were regenerated from 50 individual mature seed derived callus within two to three months. This protocol has the potential for large-scale production of elite plants after genetic transformation.