Abstract:

Chinese cabbage transient GUS gene expression was achieved when microspores were bombarded with gold particles coated with plasmid DNA. Helium rupture pressures of 7.58 ×10⁶ Pa and the particle size of 0.6 μm did not significantly affect the viability of microspores of Chinese cabbage. Under optimized bombardment conditions for Chinese cabbage microspores（7.58 × 10⁶ Pa rupture pressure，stopper-to-target-cell distance of 9 cm，0.6 μm particle size，500 μg gold particles per bombardment，and five shots），more than 20 GUS-positive microspores per petri dish were observed after 1 day of culture. The highest number of stably transformed embryos was four per dish in our test results. Collection of microspores of 40 buds，more than 20 transformed embryos were observed. The results of this study suggest that particle bombardment of microspores could be an alternative method for genetic transformation of Chinese cabbage，and may help advance the breeding research and the gene functional analysis of Chinese cabbage.

Key words: Chinese cabbage, microspore culture, particle bombardment, transformation