水稻SSR及Indel分子标记在籼粳交F_2群体的偏分离分析

偏分离是指遗传标记的观察频率偏离预期的孟德尔式分离频率的现象,其可以增加群体中杂合等位基因或者异型染色体的频率,是一种重要的进化动力。本研究以粳稻材料日本晴及籼稻材料千粒稻为亲本获得80株F2群体,构建了一张含92对SSR标记和44对Indel标记的遗传图谱。结果发现,F2群体中,116个标记表现为偏分离现象(85.29%),其中79个极度偏分离(68.10%)。偏分离标记中由合子偏分离引起的有20个,配子偏分离引起的93个,RM3484,RM3702,os7-38.4既不是由合子选择引起也不是由配子选择引起。Indel标记偏分离率(97.72%)明显高于SSR标记偏分离率(79.34%),且所有偏分离标记皆偏向于千粒稻。结合本研究结果,对偏分离现象产生的原因进行了分析。

Analysis of Segregation Distortion of SSR and Indel Markers in F2 Population Derived from the Cross of Indica and Japonica Rice

Segregation distortion refers to the phenomenon observed deviations from the expected frequency of genetic markers of Mendelian frequency separation, which has attracted considerable attention as an evolutionary force that can cause an increase in the population frequency of the heterozygous allele or heteromorphic chromosome.In this study,a rice genetic linkage map comprising 92 SSR and 44 Indel markers loci was constructed using an F2 population consisting of 80 lines from a sub-specific cross between japonica rice Nipponbare and indica rice Qianlidao. The results showed that F2 population was significantly distorted. Among these markers, 116 markers showed segregation distortion（85.29%）, 79 markers extreme showed segregation distortion（68.10% ）. Segregation distortion caused by the choice of the zygote has 20, gamete select caused 93, RM3484, RM3702, os7-38.4 is neither caused by a homozy- gous select nor gametes select. Segregation distortion rate for Indel markers （97.72%） were significantly higher than that for SSR markers （79.34%）. All marks deviated preference to paternal Qianlidao. The causes of segregation distortion were discussed based on the results and previous report.