Efficient Regeneration from In Vitro Culture of Young Panicles of Rice (Oryza sativa L.)

Factors affecting the regeneration of rice plants from young panicles, such as developmental stage of young panicles in different genotypes, sterilizing methods, duration of 4℃ treatment, induction, differentiation and rooting conditions, etc., were investigated. The results showed that the optimal conditions for different genotypic rice were as following: after the best developmental stage (Ⅲ~Ⅳ of <italic>indica</italic>, Ⅰ~Ⅱ of <italic>japonica</italic>, Ⅴ of wide compatible variety, WCV) of young panicles was treated at 4℃ within 5 days, the materials were sterilized with 0.5% potassium hypochlorite for 20 minutes, cultivated in YS-Y medium about 20 days to induce the calli, then transferred to YS-YF、YS-F medium about 15 days to regenerate shoots and YS-SG medium for 1~2 weeks to induce the roots. Under the optimal conditions, the frequency of green shoot differentiation was a little more than 85% (<italic>indica</italic>), 90% (<italic>japonica</italic>), 85% (WCV), the frequency of root regenerated was about 115% (<italic>indica</italic>), 130% (<italic>japonica</italic>), 115% (WCV), respectively. Therefore a high efficient regeneration system from <italic>in vitro</italic> culture of young panicles of rice was established for genetic transformation of rice.