[Establishment of an efficient regeneration system for Chinese cabbage cultured in vitro and histological observation...

An efficient plant regeneration system from explants of petiole with cotyledon was developed for Chinese cabbage (Brassica campestris ssp. chinensis Makino) in our study. High frequency of shoot regeneration was obtained in the medium containing BAP 2 mg/L, NAA 0.45 mg/L and 5-7.5 mg/L AgNO3 solution to the half of NH4+ concentration's MS basic medium, with 84.3 percent being the highest frequency of shoot regeneration in seven Chinese cabbage cultivars and one parentage, and the new formed shoots were observed six days after inoculation. Factors influencing in vitro explant regeneration were further studied. The results showed that there was positive correlation between frequency of shoot regeneration and number of shoots per explant. The regeneration plants produced flowers and fruits after about 50 days with low temperature treatment from 8 degrees C to 16 degrees C. Moreover, histological observation indicated that the mode of plant regeneration in B. campestris ssp. chinensis was similar to that of other Brassica crops, and adventitions buds were formed from globular meristematic cluster which derived from the cells of vascular parenchyma at the cut surface of petiole.