白菜型油菜亚种间杂种的合成

Production of intersubspecific hybrids of Brassica campestris

采用蕾期人工去雄与辅助授粉的方式,以白菜型油菜十月红菜薹和黄芽白进行正反交,以较高的频率获得了杂种后代。杂种后代叶型、株型和花等形态均表现为双亲的中间型。叶片颜色比黄芽白更深,均偏向十月红菜薹的紫红色;植株表现出较强的杂种优势,株高大于双亲,产生大量的分枝,角果数远多于双亲。杂种后代花器官发育正常,可育花粉为99%以上,且自交结实率较高。花粉母细胞减数分裂比较正常,95%的花粉母细胞在终变期所有染色体进行同源配对,形成10个二价体,减数第二次分裂中期有部分出现染色体落后现象。杂种后代极强的杂种优势和较好的自交结实性为进一步选育具有优良特性的新型白菜型油菜提供了可能。

By artificial pollination and supplementary pollination in bud stage,hybrids were obtained through reciprocal cross of Brassica campestris L. ssp. Chinenses var. purpurea Bialey and B. campestris ssp. pekinensis in high frequency. Leaf,plant type and flower morphology of hybrids were characterized by intermediate type of their parents.The leaf color of hybrid was darker than B. campestris ssp. pekinensis,more closer to purple color of Brassica campestris L. ssp. Chinenses var. purpurea Bialey. The hybrids showed high heterosis for higher plant height,more branches and more pods than the parents,and they had a good seed setting via cross by themselves because of mature flowers which could produce more than 99% fertile pollens. It also indicated that the female gemmates were fertile in the hybrids. All of the chromosomes paired to 10 bivalents at diakinesis in 95% pollen mother cells. A few of lagged chromosomes were observed at metaphase Ⅱ. The hybrids with heterosis and good seed setting was useful for breeding new type of Brassica campestris.