甘蓝型油菜二体附加系92Ⅰ 1096附加染色体的遗传研究

Cytological studies on alien addition chromosome of disomic addition line 92Ⅰ1096 in Brassica napus L.

应用细胞学方法研究了甘蓝型油菜二体附加系 92 1 0 96( Brassica napus-carinata2 n=4 0 )和甘蓝型油菜整倍体品种宁油 1 0号 ( B.napus L.2 n=3 8)及其杂种的体细胞染色体数及花粉母细胞减数分裂过程中的染色体配对行为。结果 ,甘蓝型油菜二体附加系 92 1 0 96的体细胞染色体数稳定在 2 n=4 0条。它与宁油1 0号间的正反交杂种体细胞染色体数为 2 n=3 9条。表明二体附加系 92 1 0 96的两条外源的同源附加染色体通过雌雄配子的传递机会相等。花粉母细胞减数分裂中期 ( MI) ,杂种的 3 9条染色体配对成 1 9 +1 I,少数细胞出现了多价体 ,但在观察的所有花粉母细胞中均携有一个单价体。 92 1 0 96花粉母细胞减数分裂晚后期( AI) ,二分体细胞的染色体构型为 2 0 +2 0的细胞占 93 .54%。表明该二体附加系的附加染色体能在杂种后代中稳定传递 ,不易因遗传排斥而丢失 。

Chromosome pairing behavior in pollen mother cells meiosis and chromosome number in somatic cells were observed on a disomic addition line, 92Ⅰ1096 ( Brassica napus carinata , 2n=40), and a euploid variety of Ningyou 10 ( Brassica napus , 2n=38) and their hybrid. Results showed that the chromosome number in somatic cells of disomic addition line, 92Ⅰ1096, was 2n=40. And the chromosome number in somatic cells of reciprocal hybrid between 92Ⅰ1096 and Ningyou 10 were 2n=39. It is indicating that the two homologous alien chromosomes in the disomic addition line 92Ⅰ1096 transmitted to next generation by male or female gametes with an equal frequency. At metaphase I of PMCs first meiosis, the chromosome configuration of the hybrid was 19Ⅱ+1Ⅰ. All the PMCs observed carried one univalent, although one multivalent was found in some PMCs. At late anaphase, 93.6% of the dyad observed showed a chromosome configuration of 20+19. A conclusion could be made that the alien addition chromosomes in the disomic addition line can steadily pass on to its offspring, which can be used for gene mapping.