Establishment of Efficient Genetic Transformation Receptor System in Alfalfa

Using hypocotyls and cotyledon of Xinjiang Daye and Xinmu No.1 as materials,the effect of genotypes,explants,medium and hormones on callus induction,embryos,differentiation and root induction were studied.The results showed that in callus induction and in vitro regeneration by hypocotyls,the highest regeneration rate was 54.96%,stronger than the cotyledons and 2,4-D combined with 0.2 mg/L kinetin(KT)could act better for callus induction.The SH medium was a very effective medium for the callus induction compared to MS medium,whereas the latter was more advantageous to embryo induction than the former medium.As to XinJiang Daye and Xinmu No.1,the applicable media for induction of callus,embryos and roots were SH containing 2 mg/L 2,4-D and 0.2 mg/L KT,MS containing 1.0 mg/L BAP and 0.3 mg/L NAA,and hormone-free 1/2 MS containing 1.0 mg/L IBA when propagated respectively.