中文摘要：

前期调查研究表明,江苏是中国杂草稻危害最严重的省份之一,尤其以苏中地区最甚。本文利用具有多态性的33个共显性SSR标记,分析苏中地区的11个杂草稻种群以及苏南苏北部分杂草稻样品,以揭示江苏省主要杂草稻的遗传多样性及其来源。结果表明,苏中地区11个杂草稻群体总的遗传多样性（He）为0.1661,Shannon指数（I）为0.2872;多态位点百分率达到87.88%,等位基因数（Na）为2.1515,有效等位基因数（Ne）为1.2887。其中,泰州的遗传多样性最高而南通地区的最低。杂草稻在地区之间的遗传分化（1%）显著小于杂草稻种群之间的遗传分化（39%）,更小于种群内的遗传分化（60%）。聚类分析和主成分分析结果表明,苏中和苏南地区杂草稻以籼型为主,苏北地区存在少量粳型杂草稻;苏中地区的杂草稻与现有栽培稻品种和普通野生稻没有明显的亲缘关系,但与曾经栽培过的杂交水稻品种有关。因此,本研究相对支持江苏省杂草稻可能主要来自栽培稻的基因重组或回复突变等产生野生性状即返祖遗传的假说。苏北地区的杂草稻可能来源于稻与现今栽培稻杂交的后代。

英文摘要：

The previous investigations on occurrence and harmfulness of weedy rice in Jiangsu province showed the province is one of the most serious infestations in China, especially in the central region of Jiangsu province. Hence, in the paper, 33 pairs of codominant SSR makers were used to analyse 11 weedy rice populations in central region and other samples in northern and southern regions of this province. Our main objectives were to reveal genetic diversity and analyse the origin of weedy rice. The result showed that the genetic diversity of the 11 populations in central regions of Jiangsu province is He=0.1661, I =0.2872, percentage of polymorphic loci P=87.88%;average number of alleles Na=2.1515;effective number of alleles Ne=1.2887. Among all of 11 populations, the populations collected from Taizhou city had the maximum value of genetic diversity while those from Nan-tong had the minimum one. Genetic differentiation among regions （1%） was significantly less than among populations （39%） and within populations （60%）. UPGMA cluster analysis and principle component analysis （PCA） showed that most weedy rice popu-lations were indica in central and southern regions of Jiangsu province and a few of japonica in northern regions in the province. All of weedy rice biotypes in central and southern regions did not related with cultivated rice while related with currently- cultivated hybrid indica rice which was ever planted before. Hence, our research results relatively supported the atavistic hypothesis that weedy rice in Jiangsu probably originated from cultivated rice and varieties （accessions） through gene recombination or reverse mutation which produce wild traits. However, the japonica weedy rice in northern regions might be the offspring of the hybrid between currently-cultivated rice and wild rice Ludao.