Tissue culture of Lespedeza cuneata

In order to develop the genetic transformation,tissue culture of Lespedeza cuneata was studied in this paper.The results indicated that the best time of seed disinfectant of 2.1% NaClO was 10 min,and the pollution percentage was zero under this sterilization condition.The optimal concentrations of primary differentiation were 6-BA 1.0-2.0 mg/L,NAA 0.01 mg/L and 2,4-D 0-0.01 mg/L,on which the differentiation index could reach 2-2.5.The optimal culture medium in secondary differentiation was MS medium containing original macroelements+6-BA 2.0 mg/L+IBA 0.5 mg/L+2,4-D 0.5 mg/L.IBA was more suitable than NAA for the rooting of plantlets.The optimum concentration of IBA was 0.5-1.0 mg/L,whereas that of NAA should be less than 0.1 mg/L,since high concentration of NAA had an inhibiting effect on rooting.In order to solve the serious problem of bud etiolation,experiments with different concentrations of NH₄NO₃,MgSO₄·7H₂O,CaCl₂·2H₂O,iron salt,sugar and types of lights were conducted.The results showed that the concentration changes of N,Mg and Fe had significant effects on inhibiting etiolation,and the optimal concentrations were NH₄NO₃ 1 600 mg/L,MgSO₄·7H₂O 300 mg/L,and iron salt 83.4 mg/L.Another three factors had no significant effects on etiolation.And there were no significant differences in the generation index for all of the six factors in the etiolation experiments.