中文摘要：

杂交-渐渗在物种进化过程中起到了重要作用,本研究对人工杂交和自交构建的3个杂草稻杂种F2代群体进行遗传分析,了解各群体中来自双亲不同位点等位基因的遗传规律,并以此揭示在杂草稻的杂交-渐渗过程中双亲基因的传递是否受到自然选择而发生非随机分离.采用微卫星（SSR）和插入/缺失（InDel）分子标记,检测了F2群体各位点等位基因和基因型频率,以连续卡方（X2）方法,检验了F2代群体各位点等位基因和基因型频率的观察比值和理论比值是否相符,检测配子或合子选择对偏态分离造成的影响,对3个F2群体分子标记的各两两位点进行了连锁不平衡分析和卡方统计检验.结果显示3个群体均出现显著的等位基因非随机分离,配子选择对非随机分离影响较大,某些基因位点存在显著关联关系,表明杂草稻的杂种后代群体在杂交分离过程明显受到了自然选择,这一结果为杂交-渐渗在杂草稻适应性进化过程中的作用提供了遗传和分子证据.

英文摘要：

Hybridization-introgression plays an important role in evolution of plant species.To study the inheritance of alleles descended from different parents and explore the distorted segregation of alleles in their progeny caused by natural selection during the hybridization-introgression process,genetic analyses on three F2 populations derived from artificial hybridization between weedy rice accessions was conducted.With the aid of microsatellite（SSR） and insertion/deletion（InDel） molecular markers,gene and genotype frequencies of different loci in the F2 populations were analyzed.Chi-square（X2） statistic was used to examine the consistency of observed versus theoretical values of the segregation ratios in the F2 populations for detecting the distorted segregation.The linkage disequilibrium of paired loci in the F2 populations was analyzed with the Chi-square（X2） statistic test to determine the genetic linkage of the concerned loci.Results demonstrated significant segregation distortion of some loci in different F2 populations,of which gametic selection was effective.In addition,some loci showed significant linkage disequilibrium in the F2 populations.The results indicated clear segregation distortion in hybrid progeny of weedy rice,possibly caused by natural selection,which has provided genetic and molecular evidence that the natural selection plays an important role in the adaptive evolution of weedy rice during the hybridization-introgression process.