【摘要】 用基因组原位杂交方法(Genomicin situhybridization,GISH)研究了萝卜(Raphanus sativus,2n=18,RR)和甘蓝(Brassica oleracea,2n=18,CC)属间杂种F1减数分裂过程。结果表明杂种体细胞染色体组成为RC,2n=18,但花粉母细胞有3种类型:(1)RC,2n=18,终变期染色体平均配对构型为14.87Ⅰ+1.20Ⅱ+0.04Ⅲ+0.06Ⅳ,染色体配对主要发生在萝卜和甘蓝染色体之间;后期Ⅰ9条萝卜染色体主要以5/4和6/3的分离比移向两极,所形成配子的染色体数目和组成均不平衡,配子败育。(2)RRCC,2n=36,终变期染色体形成18个二价体;后期Ⅰ染色体均衡分离,形成RC不减数配子。(3)RRCC亚倍体,2n=30~34,少数萝卜染色体丢失,形成的配子具有全套的甘蓝染色体和部分萝卜染色体。更多还原

【Abstract】 Genomic in situ hybridization（GISH） was applied to study the meiosis of F₁ plants from intergeneric hybrids between radish（Raphanus sativus,2n=18,RR） and cabbage（Brassica oleracea,2n=18,CC）.The result showed that its somatic cells had the expected chromosomes,RC,2n=18;but the pollen mother cells （PMCs） were different.There were three main kinds of PMCs.The first one was RC（2n=18）,and the mean chromosome pairing pattern was:14.87Ⅰ+1.20Ⅱ+0.04Ⅲ+0.06Ⅳon Diakinesis.GISH indicated that most bivalents resulted from chromosome pairing between radish and cabbage,and the nine chromosomes of R-genome were separated mostly in the ratio 5/4 and 6/3 at AnaphaseⅠ,so the chromosome number and components in gametes were not in equilibrium and the gametes were sterile.The second was RRCC（2n=36） with normal chromosome pairing and separation,producing unreduced gametes.And the third was nullisomic of RRCC in PMCs（2n<36）.GISH showed that some radish chromosomes were lost in those PMCs,and its gametes had nine cabbage chromosomes and partial radish chromosomes.The mechanism of this chromosome reduplication was discussed in this paper.更多还原