用胚挽救法创建甘蓝×大白菜抗根肿病新材料

为改良甘蓝Brassica oleracea L.var.capitata的根肿病抗性,以2个甘蓝品种D2、B1为母本和2个抗根肿病大白菜品种CR-英雄、CR-春美杂交,比较4个远缘杂交组合的亲和性,运用胚挽救技术获得试管苗并对远缘杂交种进行真假杂种鉴定、育性研究以及根肿病抗性鉴定来创建和筛选根肿病抗性新种质。结果表明,杂交组合D2×CR-春美的结荚率为86.08%,高于其它组合,而成活的幼胚数/授粉花蕾数和试管苗数/授粉花蕾数以组合D2×CR-英雄最高,分别达15.96%和8.16%,4个组合D2×CR-英雄、D2×CR-春美、B1×CR-英雄、B1×CR-春美分别获得23、8、2、2株试管苗。细胞学鉴定发现杂种茎尖的染色体是19条,结合形态学鉴定确定为真杂种。组合D2×CR-英雄获得的试管苗只有1个株系有花粉,花粉萌发率为0.90%,极显著低于母本对照的40.58%;对该组合的试管苗进行苗期抗根肿病鉴定,有8个株系抗11号生理小种,3个株系抗4号生理小种。表明通过胚挽救技术可筛选到杂交效率较高的远缘杂交组合以及抗根肿病材料。

Development of new materials resistant to clubroot by crossing Brassica oleracea with Brassica campestris via embryo rescue

To improve clubroot resistance of Brassica oleracea, hybrids between two B. oleracea D2, B1 and two resistant B. campestris cv. CR-Yingxiong and CR-Chunmei were developed. In the four crosses, a few embryos and plants were obtained via embryo rescue and tissue culture. By comparing the compatibility of these crosses, the frequency of pods per flower between D2 and CR-Chunmei was 86.08%, higher than others, while higher frequencies of immature embryos survived/buds pollinated and plantlets/buds pollinated were observed in the interspecific hybridization between D2 and CR-Yingxiong, which were 15.96% and 8.16%, respectively. The plant numbers of four crosses, D2×CR-Yingxiong, D2×CR-Chunmei, B1×CR-Yingxiong, B1×CR-Chunmei, were 23, 8, 2, and 2, respectively. These plants derived from interspecific hybridization were identified with 19 chromosomes in tissue cells, showing intermediate morphology between parents. All the plants had little pollen, except one plant with a little pollen (the rate of pollen germination was 0.90%), which was significantly lower than that of parental species D2(40.58%). The clubroot resistance of plants derived from hybrid between D2 and CR-Yingxiong was evaluated in seedlings, which showed that eight lines were resistant to Race 11, and three lines were resistant to Race 4. The results indicated that highly efficient cross was screened and materials resistant to clubroot were developed by interspecific hybridization between B. oleracra and B. campestris via embryo rescue.