The role of alternating culture temperatures and maltose in enhancing the anther culture efficiency of salt tolerant indica rice (Oryza sativa L.) cultivars, Pokkali and Nona Bokra

The effects of different culture temperatures, culture media and saccharides on the anther culture efficiency in two salt tolerant rice (Oryza sativa ssp. indica) cultivars, Pokkali and Nona Bokra, were examined. Comparison of two culture temperatures (constant temperature at 25 degrees C and alternating temperatures at 30 degrees C/20 degrees C) indicated that alternating temperatures showed remarkable effects not only on the callus induction but also on the plant regeneration. Among the basal media examined, higher callus productivity was observed in SK-I medium and higher shoot productivity was obtained in SK-II medium than other basal media. When alternating temperatures and revised N-6 medium including maltose were used throughout anther culture, callus productivity and green shoot productivity showed the highest score in the salt tolerant two cultivars used in this study. Maltose and alternating temperatures increases the anther culture efficiency of recalcitrant indica rice cultivars. This is the first report suggesting high production of haploids or doubled haploids from anther culture of these salt tolerant indica cultivars.