In vitro Culture and Rapid Propagation of Stem Segments with Buds of Lagerstroemia indica
The semi-lignified stem segments with buds of Lagerstroemia indica'Caixia Mantian'with dark pink petals were used as explants to optimize the in vitro culture system from the aspects of dis-infection and sterilization,primary medium and proliferation medium.The results showed that the ap-propriate disinfection method for stem segments of L.indica was to first soak them in 75%alcohol for 18 s,and then soak them in 5%NaClO solution for 8 min.The optimal initiation medium for stem segment with axillary buds was 1/2MS+6-BA 1.0 mg·L-1+NAA 0.1 mg·L-1+sucrose 20 g·L-1+agar 6.3 g·L-1,with an average induction rate reaching 45%,and then the buds had the best growth and the leaves was tender green in color.The L9(33)orthogonal experiment design was carried out with three factors:basic medium,6-BA concentration and KT concentration.The main and secondary factors affecting the effective proliferation coeffi-cient of L.indica tissue culture seedlings were found to be:6-BA>basic medium>KT.The culture media with the best effect on the proliferation and growth of the L.indica seedlings were MS+NAA 0.05 mg·L-1+6-BA 2.0 mg·L-1+KT 4.0 mg·L-1+sucrose 30 g·L-1+agar 6.3 g·L-1 and WPM+NAA 0.05 mg·L-1+6-BA 2.0 mg·L-1+KT 4.0 mg·L-1+sucrose 30 g·L-1+agar 6.3 g·L-1.