Effect of Culture Medium Strength, Plant Growth Regulators and Ethylene Inhibitors for Adventitious Bud Induction from Mature Zygotic Embryo in Larix kaempferi

摘要

Adventitious buds were produced from the cultures of mature zygotic embryos of Larix kaempferi with the highest frequency in Quoirin & Lepoivre (LP) medium containing 1.0 mg/L zeatin (76.1%). The effective treatments for inducing adventitious shoots growth above 2 mm were shown in Litvay (LM) medium with 0.5 mg/L zeatin (75.2%) or LP medium with 2.0 mg/L zeatin (70.2%), respectively. In experiment with half strength salts medium for induction of the adventitious buds, the effective treatments were obtained from !4LP medium with 1.0 (83.3%) or 2.0 mg/L (81.7%) zeatin, respectively. However, the best adventitious shoot growth more than 2 mm appeared in /4LM medium with 1.0 mg/L zeatin (66.7%). In experiment with half strength salts medium for induction of the adventitious buds, the effective treatments were obtained from1/2LP medium with 1.0 (83.3%) or 2.0 mg/L (81.7%) zeatin, respectively. However, the best adventitious shoot growth more than 2 mm appeared in 14LM medium with 1.0 mg/L zeatin (66.7%). In experiment of subsequent treatment with various cytokinins for induction of the adventitious buds, the best one (52.9%) was obtained from 1.0 mg/L zeatin for 2weeks, and then subcultured to the medium with 1.0 mg/L thidiazuron (TDZ). The effect of ethylene synergist or inhibitor on adventitious buds induction was examined. The highest rate (34.6%) of adventitious buds marked from the treatments of 1.0 mg/L zeatin+2.0 mg/L MGBG (methylglyoxal bis-[guanylhydrazone]). And the highest no. of adventitious buds( 1.5/explant) was shown in the medium with 1.0 mg/L zeatin+2.0 mg/L CoCl_2.