Study on Microspore Culture-Based Haploid Breeding Technology of Chinese Kale（Brassica oleracea）

【Objective】To improve the breeding efficacy of Chinese kale, the procedure of microspore culture-based haploid breeding technology was studied.【Method】Mechanical crushing with centrifuge tube was used to extract isolated microspores of Chinese kale instead of artificial grinding, regenerated plantlets were treated with cholchicine, and other steps were also optimized.【Result】There was no significant difference in the embryoid induction rate（11.96%）of microspores of Chinese kale extracted by mechanical crushing and that by artificial grinding（10.80%）. Mechanical crushing could be used to treat samples in a batch to improve the extraction efficiency of microspores of Chinese kale. The microspores of Chinese kale collected by the two methods were cultured, a total of 255 embryoids were induced and 112 regenerated lines obtained after subculture and rooting culture. The treatment with colchicine improved chromosome doubling of regeneration plantlets（most of which were haploid）, leading to a DH attainment rate of 56.45%, 3.07 times higher than that of non treatment. Through the procedure, 41 DH lines were obtained from different donor varieties.【Conclusion】An integrated and effective microspore culture-based haploid breeding procedure was developed, which could be applied in breeding practice of Chinese kale to improve breeding efficacy.