Studies to Investigate the Interactions of Genotypes, Culture Media and Culture Temperatures on Androgenesis in Recalcitrant Indica Rice (Oryza Sativa L.)

Production of doubled haploids through androgenesis is well established in japonica rice and successfully used to develop high yielding varieties. However, indica rice is remaining recalcitrant to this in vitro technique. To understand the interactions of genotypes, culture media and culture temperature, two indica varieties (Pokkali and Nona Bokra) were cultured on three culture media under normal (25 degrees C) and alternate temperatures (30 degrees C/20 degrees C, 14 hours/10 hours). The responses of the recalcitrant varieties were examined at callus induction and regeneration stages. Pokkali was found responsive to culture media as well as culture temperatures. Although there was an increase in albino shoot production but green shoot productivity was recorded nine fold under alternate temperatures. Interactions of recalcitrant indica genotypes, culture media and culture temperatures were found significant at callus induction and regeneration stages. It is therefore reflected that to activate the recalcitrant genes for callus induction and regeneration of green shoots, interaction of genotypes, culture media and culture temperatures could play significant role. Pokkali responded well to SKI and SK II rather than others, indicated that alteration of culture media composition would be an important aspect in future investigation.