Micropropagation of traditional deep water rice (Oryza sativa L.) cv. TNR1 for viable seed production and germplasm conservation

Extinction of traditional crop varieties is becoming a common scenario in the world due to adoption of hybrid/improved varieties. Conservationists are very busy with protection of those verifies for novel genes to develop agriculture through molecular breeding. However conservation feasibility is always questionable for traditional seeds because of recalcitrance and low viability in nature. This is the first report on the protection of traditional deep water rice (Oryza sativa L.) cultivar, TNR1 from possible extinction using callus induction and regeneration system. TNR1 is known for its traditional (antidiabetic) and genetic (salinity and submergence resistance genes) importance. The matured embryos were inoculated on LS medium prepared with 2.5 mg L-1 2, 4-D and 0.1 mg L-1 KN showed 74.5% of embryogenic callus induction. The calli was regenerated on MS medium fortified with 1.5 mg L-1 NAA and 3.0 mg L-1 BAP and obtained 83.4% of regeneration. Regenerated plants were successfully acclimatized in the field with 100% survival. The germination percentage of tissue culture derived seeds was found to be high (84.2%) compared to traditional seeds (36.4%). The outcome of this study revealed that, tissue culture enhanced the viability of recalcitrant seeds. In future, this protocol will be an invaluable tool for both transgenic plant production or conservation of threatened traditional rice germplasms.