基因组原位杂交辨别芸薹属异源四倍体AA、BB、CC基因组研究

利用基因组原位杂交（GISH）技术，以标记的白菜型油菜（AA，2n=20)的基因组总DNA）为探针，分别同芥菜型油菜（AABB，23n=36）和甘蓝型油菜（AACC，2n=38)的中期染色体和间期核杂交，结果芥菜型油菜有20条染色体表现大而明亮的杂交信号，其它染色体上信号很弱或无，可以区分A、B基因组，甘蓝型油菜染体上表现有38个信号，A、C基因组不能分区分开来。以黑芥（BB,2n=16）的基因组总DNA为探针与埃塞俄比亚芥（BBCC，2n=34）的中期染色体和间期核杂交，16条染色体上显示明显的杂交信号，其它染色体上信号很弱，说明在长期的进化过程中，芸薹属中BB与AA和CC基因组间分化程度较大，而AA与CC基因组分化较小，基因组原位杂交表明最强的信号多集中分布于着丝粒区，本文讨论了这种分布的可能原因。

Genomic in situ hybridization (GISH) discriminates the A, B and C genomes in Brassica allotetraploid species

Genomic in situ hybridization (GISH) was used to discriminate between the A and the B genomes in allotetraploid B.juncea species, the B and C genomes in B.carinata . The labeled total DNA of B.rapa was hybridized to the metaphase chromosomes and interphase of B.juncea and B.napus . 20 large, strong signals were detected in B.juncea , 38 in B.napus . The A and B genome chromosomes were obviously distinguished in B.juncea , but the A and C genomes were not discriminated in B.napus . Using the B.nigra total DNA as probe, the 16 chromosomes showed strong signals and the other showed weak signals in B.carinata . The results indicated that the B genome was divergent from the A and C genomes and the A and C genomes were relativety close. The hybridization signals were generally distrlibuted on centromere other than the arms of the chromosomes, the possible reason was discussed.