Sterilized kernels of a zinc-rich rice variety Chittimuthyalu were initially cultured in modified MS with 2.5 mg/l 2, 4-D + 0.5 mg/l Kn for callus induction. The callus induced was transferred to a modified MS medium supplemented with 0.5 mg/l NAA + 2.0 mg/l BAP for study of plant regeneration response. A series of culture variables at varying levels were tested as independent experiments to optimize callus induction and morphogenetic response of the variety. There was a continuous improvement in callusing and plant regeneration response in subsequent follow-up steps. Supplementation of 500 mg/l casein hydrolysate, 150 mg/l proline, 3% sucrose, 0.3% agar + 0.2% phytagel revealed rapid callus induction and highest callusing response under dark condition. Somatic embryogenic plant regeneration was improved at 2.5% sucrose under 12-h photoperiod using 4 week old partially desiccated calli. The optimized high throughput callus induction and regeneration system realized in this study can be suitably used for genetic transformation and in vitro mutagenesis in zinc-rich rice.
Key words: Callus induction and plant regeneration, media supplements, culture conditions, zinc rich rice.
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