甘蓝与芸薹属5个近缘物种的基因组原位杂交分析

利用基因组原位杂交(GISH)技术，研究了甘蓝基因组与芸薹属其它5个近缘物种基因组间的相互关系。以标记的甘蓝(CC，2n=18)的基因组总DNA为探针，分别同二倍体甘蓝、白菜型油菜(AA，2n=20)、黑芥(BB，2n=16)和异源四倍体芥菜型油菜(AABB，2n=36)、埃塞俄比亚芥(BBCC，2n=34)、甘蓝型油菜(AACC，2n=38)的中期染色体杂交，甘蓝、白菜型油菜和甘蓝型油菜的所有染色体上都有杂交信号，不能区分A、C基因组。黑芥染色体上只有零星的弱小信号，埃塞俄比亚芥的中期染色体显示出18个明显的信号，可以区分出C、B基因组；芥菜型油菜的中期染色体显示出20个明显的信号，其余染色体上信号很弱或无，可以区分出A、B基因组。说明在长期的进化过程中，甘蓝与白菜型油菜、甘蓝型油菜的亲缘关系较近，基因组的分化程度较小，而甘蓝与黑芥的亲缘关系较远，基因组的分化程度较前者高；甘蓝与芥菜型油菜和埃塞俄比亚芥间的亲缘关系介于上述二者之间。

Genomic in situ hybridization (GISH) analysis of B.oleracea and 5 related Brassica species

Genomic in situ hybridization (GISH) was used to study the relationship between B. oleracea ge- nome and 5 related Brassica species. The labeled total DNA of B. oleracea was hybridized to the metaphase chromo- somes of B. oleracea, B. rapa, B. nigra, B. juncea, B. carinata and B. napus. Strong signals were detected in each chromosomes of B. oleracea, B. rapa and B. napus, the A and C genomes were not discriminated. The scattered sig- nals detected in B. nigra were very faint and small. The 18 chromosomes showed strong signals and the otheT show weak signals in B. carinata, the C and B genome chromosomes were obviously distinguished. The 20 chromosomes showed strong signals and the other show weak signals in B. juncea, the A and B genome chromosomes were also obviously distinguished. The results indicate that, in the course of long -- term evolution, B. oleracea had very closed relationship with B. rapa and B. napus, division of genome degree was relatively little; and the relationship between B. oleracea and B. nigra was relatively far, the division degree of the genome was higher than the former. The relationship between B. oleracea and B. juncea, B. carinata was lied between above -- mentioned two.