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偏分离是指观察到的基因型频率偏离预期的孟德尔频率的遗传分离方式,在大多数的遗传定位研究中非常普遍。在之前我们发表的遗传连锁图中,107个SSR标记在BC1作图群体[(Emian 22×3-79)×Emian22]中表现偏分离。为阐明这些偏分离标记的遗传机制及其在其它群体中的偏分离情况,将其中97个共显性标记在另外两个回交群体中进行验证。结果表明,原图谱中的61个偏分离标记在另外2个回交群体中都表现正常分离,说明杂交方式是导致偏分离的一个重要因素。36个偏分离标记至少在两个群体中仍表现偏分离,偏分离应该是配子选择的结果。偏分离标记分布于14条染色体上,其中D亚基因组上的分布多于A亚基因组。偏分离标记在在第2、第16和第18染色体上分布最多,暗示在这些染色体上存在偏分离位点,该结果有助于在棉花中鉴定偏分离位点。
Partial segregation refers to the genetic segregation of the observed genotype frequencies away from the expected Mendelian frequencies and is prevalent in most genetic mapping studies. In our previously published genetic linkage map, 107 SSR markers showed partial segregation in the BC1 mapping population [(Emian 22 × 3-79) × Emian22]. To clarify the genetic mechanism of these partial segregation markers and their partial segregation in other populations, 97 of them were validated in two other backcross populations. The results showed that the 61 partial segregation markers in the original map showed normal segregation in the other two backcrosses, indicating that hybridization is an important factor leading to partial segregation. Thirty-six partial segregation markers still show partial segregation in at least two populations. Partial segregation should be the result of gamete selection. Partial segregation markers were distributed on 14 chromosomes, of which D sub-genome distribution more than A sub-genome. Partial segregation markers are most distributed on chromosomes 2, 16 and 18, suggesting the presence of partial segregation sites on these chromosomes, a finding that helps to identify partial segregation sites in cotton.