Construction the System of High Frequency Regeneration from Callus of Alfalfa and Study on the Effect Factors

A high frequency regeneration system of Medicago sativa L. has been developed from the cotylend and hypocotyl by studying on the effect factors about 2,4 D, KT, sucrose and the type of medium. The system consists of modified SH macronutrients + MS micronutrients + CH 2 mg·L -1 + agar 8 g·L -1 + VB 1 9.9 mg·L -1 +VB 6 9.5 mg·L -1 +Nicotinic acid 4.5 mg·L -1 . Base on the system, add 2,4 D 2 mg·L -1 , KT 0.025 mg·L -1 and sucrose 30 g·L -1 for the callus initiation and maintain medium, add KT 0.4 mg·L -1 and sucrose 20 g·L -1 for the differentiate medium. The rooting medium consists of 1/ 2 MS+10 g·L -1 sucrose. In this system, the differentiate ratio from cotylend and hypocotyl of Peru alfalfa is 100%, 92% separately. The period of regeneration is only 60-70 days.