Department of Vegetable Crops, University of California, 95616, Davis, CA, USA.
Theor Appl Genet. 1992 Aug;84(5-6):544-54. doi: 10.1007/BF00224150.
A composite linkage map of Brassica oleracea was developed from maps of four different populations, derived from 108 DNA, isozyme and morphological loci covering over 747 centimorgans in 11 linkage groups. Of these linkage groups, 8 were assigned to their respective chromosomes by alignment with gene synteny groups of B. oleracea. Distortions in segregation ratios increased with the level of divergence of the parents and were attributed to differentiation of parental chromosomes. Comparison of the individual maps demonstrates that the B. oleracea genome undergoes frequent chromosomal rearrangement, even at the subspecies level. Small inversions were the most frequent form of aberration followed by translocations. The former type of aberration could occur without a noticeable effect on meiotic behavior of chromosomes or on pollen fertility. The obvious deduction from the composite map is that a large fraction of the B. oleracea genome is duplicated, falling into three classes: randomly dispersed, linked-gene families, and blocks duplicated in non-homologous chromosomes. The genealogy of chromosomes sharing duplicated segments was formulated and indicates that B. oleracea is a secondary polyploid species derived from ancestral genome(s) of fewer chromosomes.
甘蓝型油菜的复合连锁图谱由来自于四个不同群体的图谱构建而成，这些群体源自于 108 个 DNA、同工酶和形态学标记，覆盖了 11 个连锁群中的 747 个遗传单位。在这些连锁群中，有 8 个通过与甘蓝型油菜的基因同线性群的比对被分配到各自的染色体上。分离比的扭曲程度随着亲本的分化程度而增加，归因于亲本染色体的分化。个别图谱的比较表明，甘蓝型油菜的基因组经常发生染色体重排，甚至在亚种水平也是如此。小的倒位是最常见的畸变类型，其次是易位。这种畸变类型的发生不会对染色体的减数分裂行为或花粉活力产生明显影响。从复合图谱中可以明显推断出，甘蓝型油菜基因组的很大一部分是重复的，分为三类：随机分散的、连锁基因家族和非同源染色体上重复的块。共享重复片段的染色体的系谱被构建，并表明甘蓝型油菜是一种次生多倍体物种，由较少染色体的祖先基因组衍生而来。
