Studies on high efficient in vitro shoot regeneration from cotyledon of Chinese cabbage

The cotyledons were used as explants from two excellent quality Chinese cabbage cultivars, Aichi Hakusai (C_(1)) and Shinriso Hakusai (C_(2)), introduced from Japan. Effects of hormone combinations, AgNO_(3) concentration and seedling age on shoot regeneration from cotyledon were studied. The results were as follows. COmpared with 6-BA, TDZ was more effective in inducing shoot regeneration. The shoot regeneration percentage from cotyledons of the two cultivars reached 75.0% and 55.0% respectively in MS medium containing 0.5 mg•L~(-1) NAA and 1 mg•L~(-1) TDZ. Adding 5 mg•L~(-1) AgNO_(3) into the above medium could further increase the frequency of shoot regeneration up to 96.7% and 80.0% respectively, and seedling age from 5 to 8 days was the best.