Abstract

Myrica rubra is an important horticultural, forestry and ornamental tree. Its micropropagation was achieved by using shoot tip and nodal explants from two commercial cultivars “Biji and Dongkui” on BW medium supplemented with Thidiazuron (TDZ) and/or 2,4-Dichlorophenoxyacetic acid (2,4-D). TDZ induced multiple shoots but stunted growth. Maximum number of shoots (5.75) was recorded for both cultivars with 0.6 mg L^-1TDZ concentration. Shoot length was significantly improved with optimum concentration of TDZ (0.6 mg L^-1) and with different  concentrations of 2,4-D. BW medium was found as suitable medium for micropropagation of both the cultivars of M. rubra with maximum number and longer shoots. WPM and MS medium ranked second in multiple shoot regeneration of both cultivars. Single microshoot cultured on plant growth regulator free medium for 3 weeks initiated roots on the medium containing  Indole butyric acid (IBA) only with reduced (¼ and ½) medium strength. Roots were induced with a high frequency of 95% in Biji and 87% in Dongkui with 0.3 mg L^-1 IBA, respectively. No callus was observed on shoots in rooting media. All the concentrations of indole-3-acetic acid (IAA) either on reduced medium or full strength did not initiate any roots. Rooted plants were successfully acclimatized.

Key words: Myrica rubra, Chinese bay berry, micropropagation, plant growth regulators.