白菜型油菜黄芽白与甘蓝型油菜湘油15种间杂交及其杂种后代的遗传学特征

采用人工杂交方法,以甘蓝型油菜湘油15和白菜型油菜黄芽白为亲本进行正反交获得杂种一代,杂种一代自交产生杂种二代。结果表明,以甘蓝型油菜为母本杂交容易获得杂种后代,而反交组合却比较困难。正反交杂种一代株型和叶片形态都与甘蓝型油菜接近。在花粉母细胞第一次减数分裂前期,染色体主要形成二价体或单价体,但也有少数染色体参与非同源联会形成多价体。第一次减数分裂和第二次减数分裂的中期和后期,落后染色体和染色体桥也较多出现在花粉母细胞中。杂种一代雄蕊发育不良,花粉育性低,自交结实率也比较低。杂种二代花粉育性极显著(P<0.01)提高,自交结实率也比杂种一代极显著(P<0.01)提高。预期经多代自交,杂种育性能得到较好恢复,可以作为甘蓝型油菜改良的遗传资源。

Obtaining and genetic analysis of hybrid progeny between Brassica napus cv. Xiangyou 15 and Brassica campestris ssp. pekinensis

In the present study, Brassica napus cv. Xiangyou 15 and B. campestris ssp. pekinensis were used as parents to obtain the interspecific hybrid, and the second generation was gained by self-crossing to obtain rapeseed germplasm with valuable traits. And the meiosis of pollen mother cells (PMCs) were observed via microscope. The results showed that it was easier to obtain hybrid progenies when B. napus was used as female parent, but it was more difficult when B. campestris was used as female parent. The plant type and leaf morphology of progenies from reciprocal crosses were similar to those of B. napus. At the diakinesis, the majority of the chromosomes formed bivalents or univalents, and a few of chromosomes formed multivalents. At metaphase and anaphase, laggard chromosomes and anaphase bridges were observed in PMCs. The stamen did not develop very well and a lot of pollens were not fertile, and the seed setting rate was relatively low in the first generation. The pollen fertility and seed setting rate of the second generation were significantly (P<0.01) higher than those of the first generation. It is expected that the hybrid fertility will be restored well via selfing crossing, which can be used as genetic resources for further genetic improvement of B. napus.