Variation of endogenous hormones in formation of microtuber of Dioscorea opposite in vitro

OBJECTIVE: Through analysis of variation and function of 5 main endogenous hormones in the formation of microtuber of Dioscorea opposite in vitro to explore the physiological and biochemical mechanism of microtuber development. METHOD: When microtubers were induced on MS + 6-BA 1.5 mg x L(-1) + NAA 1.5 mg x L(-1) + sucrose 5% medium, the endogenous hormones were isolated during different formation stages of microtubers, then purified and detected with enzyme-linked immunosorbent assays (ELISA). RESULT: The results showed that GA3 slightly decreased in initial period, rose suddenly 20 days later, and than decreased. IAA showed a dropping tendency in the total course, ABA and ZR increased in a long period, dropped at last. JA continuously rose and never dropped, GA3 and ABA and the ratio of GA3 and JA varied obviously. CONCLUSION: IAA, ABA, JA , ZR and GA3 play an important role in controlling formation of microtubers in D. opposite in vitro.