芥菜型油菜与埃塞俄比亚芥杂种基因组原位杂交分析

原产于非洲的埃塞俄比亚芥(Brassica carinata,2n=34,BBCC)具有适应于炎热干旱地区种植等特点,是改良我国芥菜型油菜(B.juncea,2n=36,AABB)的重要种质资源。本研究用基因组原位杂交方法(GISH,Genomic in situ hybridization)分析了芥菜型油菜与埃塞俄比亚芥种间杂种花粉母细胞的染色体分离,发现在后期I染色体主要以17∶18类型分离,其次是16∶19,染色体落后现象偶然发生,其中B染色体组以8∶8的分离比率较高,表明不同来源的B染色体可正常配对分离。本研究表明,芥菜型油菜与埃塞俄比亚芥远缘杂交,通过染色体同源重组(B染色体间),以及部分同源染色体配对交换的方式(A、B、C基因组间),有可能将埃塞俄比亚芥优良遗传成分转移到芥菜型油菜中。

GISH analysis of interspecific hybrid between Brassica juncea and B. carinata

Brassica carinata originating from Africa with good adaptation in drought and hot environment is an important genetic source to improve B. juncea, which has been widely sown in the Northwest of China. The technique of genomic in situ hybridization (GISH) was adopted to investigate the chromosome segregation of interspecific hybrid (ACBB, 2n = 35) between B. juncea and B. carinata during meiosis. The predominant segregation pattern of chromosomes was 17:18 in pollen mother cells (PMCs), followed by 16:19, while lagged chromosomes were occasionally observed. And the major segregation pattern of B-genome chromosomes from two species was 8:8. Our data suggest that it will be possible to transfer the genetic component of B. carinata into B. juncea via homologous recombination within B genome and homeologous recombination among three genomes.