Study on the Effect of Different Hormones Combinations on the Callus Induction of Soybean Cotyledon

[Objective] The effect of the different hormones on the callus formation from soybean cotyledon culturing was studied.[Method] The cotyledon of the soybean variety—Dongnong No.42 with high content of protein was cultured in the medium containing two combinations of growth regulators: 2.0 mg/L of 2,4-D+1.0 mg/L of KT and 2.0 mg/L of 6-BA + 0.2 mg/L of NAA to analyze the induction efficiency of the callus formation from cotyledon.[Results] In the medium with 2.0 mg/L of 6-BA + 0.2 mg/L of NAA the rate of callus induction was 71.4% and in the medium with 2.0 mg/L of 2,4-D+1.0 mg/L of KT,78.6%,which callus was with the color of green and compacter;in the medium without the addition of hormone the rate of callus induction was 85.7%,which did not appear the growing sign.The addition of growth regulator could promote the callus formation,but the different hormone had variation ability in its induction and the best induction efficiency was from the medium with 2.0 mg/L of 2,4-D+1.0 mg/L of KT.[Conclusion] The induction of soybean cotyledon callus varied with the addition of hormone and the best medium for its induction was the medium MS with 2.0 mg/L of 2,4-D+1.0 mg/L of KT.