Study on plant regeneration in diverse cultivars of Medicago sativa

In vitro plant regeneration in diverse cultivars of Medicago sativa (Longdong, Hetian, Zhungeer and Rambler) and their different donor tissues were studied. The results showed that diverse cultivar,explant and different exogenous hormone and concentration had obvious effect on plant regeneration of Medicago sativa, in which, the cultivar Longdong and Hetian were the optimum genotype for callus induction and somatic embryogenesis. The frequency of callus induction and somatic embryogenesis from hypocotyls of Longdong was (91.04%) and 63.75% respectively, The callus induction rate was as high as 92.05% from hypocotyls of Hetian, it's frequency of somatic embryogenesis was 56.82%. Hypocotyl was the optimum donor tissue for rapid and higher frequency induction of callus and promoted further embryos development in Medicago sativa. All selected cultivars exhibited high frequency in callus induction and somatic embryogenesis on solidified MS medium supplemented with 2.0 mg/L 2,4-D or 2.0 mg/L 2,4-D+(0.5-2.0 mg/L) 6-BA for two weeks, and the later had a better performance. Somatic embryos could develop and plantlets could regenerate on solidified MS medium supplemented with 2.0 mg/L 6-BA or 2.0 mg/L 6-BA+0.5 mg/L NAA. Plants rooted on 1/2 MS medium supplemented with 1.0 mg/L IBA, 1% sucrose and 0.7% agar.