Abstract: An efficient transformation method for kale(Brassica oleracea var. acephala)cultivar Hongou was developed using hypocotyls as explant tissues with the following 3 steps：firstly optimizing the differentiation system of adventitious buds；secondly investigating the effects of Agrobacterium infection concentration and time on differentiation rate and the selective concentration of Hygromicin B(Hyg)gene during differentiation and rooting of adventitious buds；finally verifying the selective gene Hyg in the resistant plants by PCR. The highest differentiation rate(84.17%)of adventitious buds was found on MS + 6-BA 5.0 mg/L + AgNO₃ 9.0 mg/L medium. An infection concentration OD₆₀₀ of Agrobacterium as 0.5 and infection time for 5 min were favorable for genetic transformation, and the differentiation rate was 69.17%. The selective concentration of Hyg during the differentiation and rooting of adventitious buds were 4.0 mg/L and 30.0 mg/L, respectively. Moreover, the amplified specific gene Hyg bands were observed at the expected 602 bp by PCR analysis, which preliminarily demonstrated that the screened gene Hyg was integrated into the B. oleracea var. acephala genome.

Key words: Brassica oleracea var. acephala, Agrobacterium infection efficiency, selective concentration of hygromycin B