Effects of Kanamycin on Induction and Differentiation of Medicago sativa L Callus

[Objective] The aim of the research was to study the sensitivity of Medicago sativa L leaves to kanamycin in the period of callus induction and differentiation.[Method] Effect of kanamycin on callus formation of M.sativa leaves was confirmed and its effect on callus differentiation was also ascertained based on callus formation.[Result] Different concentrations of kanamycin had some restraining effects on callus inducement and differentiation in M.sativa leaves,and the restraining effect enhanced along with the rising concentration of kanamycin.The sensitivity of kanamycin to callus in differentiation phase was higher than that in induction phase.The selective pressure should be controlled under 25 mg/L in differentiation phase.Delaying the adding of kanamycin or reducing the concentration of kanamycin in differentiation phase were advisable methods for screening transformation seedlings.[Conclusion] This study established the foundation for using agrobacterium-mediated method in transforming M.sativa.