Abstract: Genetic diversity of 47 weedy rice accessions collected from disasterprone areas were analyzed with SRAP molecular markers to further reveal the source of weedy rice based on the genetic background of weedy rice at the level of open reading frame. Among 845 DNA bands amplified with 110 pairs of primers   590  were polymorphic, 5.4 bands per pair of primers,  accounting for  69.82%.   This implied that  with  a high amplification  efficiency at the gene coding region SRAP molecular marker   was suitable  for  genetic diversity analysis.  ShannonWeaver information index of weedy rice in China was 0.63, the  diversity index (I)  of weedy rice from the north and the south of China were  0.62 and   063. On the basis of genetic distance cluster analysis, significant genetic differentiation was detected between   weedy rice from the north and the south. Cheng′s index demonstrated that   weedy rice  from the south of China could be classified as indica rice and  weedy rice from the south   as japonica rice. 

Key words: weedy rice, open reading frame, sequencerelated amplified polymorphism, genetic diversity

摘要： 利用SRAP分子标记分析了采集于杂草稻多发地区的47份样本的遗传多样性，旨在从基因的开放式阅读框区域（ORFs）深入研究杂草稻的遗传背景，为进一步揭示其来源提供依据。结果表明，参试的我国杂草稻材料在110对引物组合中共扩增出845种类型的谱带，多态性谱带590种，多态率为6982%，平均每对引物可以检测到54条多态性谱带。说明SRAP分子标记对于杂草稻基因组开放式阅读框区域序列的多态性具有很高的检测效率，适用于遗传多样性研究。我国杂草稻材料ShannonWeaver多样性指数（I）为063，且南北方杂草稻多样性指数（I）相当，分别为063和062。聚类分析结果表明，南方收集的杂草稻与北方收集杂草稻群体间遗传分化较大，遗传差异明显。程氏指数判定结果也表明杂草稻呈南籼北粳的分布状态。

关键词: 杂草稻, 开放式阅读框, 相关序列扩增多态性, 遗传多样性