Control of Browning in the Tissue Culture of Chinese Hickory

Experiments were carried out to solve the problem of browning during the shoot-tip culture of Chinese hickory grown in Southern Anhui and Dabieshan mountainous area. Results showed that browning varied remarkably with the age of trees and the position on the tree from which the material was sampled. For reduction of browning and good differentiation and growth of the explanted tissue, the explant was first inoculated on 1/2 MS medium added with 2 g of activated carbon at 5℃ for 7 days in the dark. Then the explants were transplanted on DKW medium added with 1.0 mg/L of 6-BA, 0.01 mg/L of IAA, and 5 ml/L 20% Na_2S_2O_3 at 25℃ in the light for 15～20 days. The culture medium wasrenewed at an interval of 3～5 days. This method effectively inhibited the browning, and the explant tissue differentiated and grew normally in the whole culture process.