Abstract

We selected two cultivars of Brassica campestris ssp. pekinensis (Chinese cabbage), ‘Futian 50’ and ‘Changkuai,’ to investigate the factors that influence microspore embryogenesis and plantlet regeneration. We have also discussed some protocols for the induction culture of microspore-derived embryos and for rooting and transplantation of microspore-derived plantlets. We obtained the following findings in our study. Although NAA promotes the development of embryo and reduces the percentage of abnormal embryos, it inhibits the formation of microspore-derived embryos. 2,4-D also inhibits the formation of microspore-derived embryos. Low concentrations of cytokinins facilitate embryogenesis, while high concentrations inhibit embryogenesis; BA has a stronger influence than zeatin (Z) on embryo induction. The combined effects of auxin and cytokinin are synergistic. Organic compounds increase the rate of formation of microspore-derived embryos. However, activated charcoal (AC) inhibits embryo development. The better the development of the embryos, the higher is the plantlet regeneration rate. The plant regeneration rate increased significantly on the MS culture medium supplemented with 200 mg·L^-1 AC. The MS medium s suitable for the subculture of the regenerated plantlets. MS medium containing 0.1 mg·L^-1 NAA is the optimal medium for rooting of microspore-derived plantlets.

Key words: Chinese cabbage, microspore culture, embryogenesis, plant regeneration.