Abstract: Genetic differentiation and indica component degree analysis were conducted on the main parents of japonica hybrid rice in the northern China by simple sequence repeats(SSR). The genomic DNAs of the main parents were amplified with 15 primers. Fifty two polymorphic markers were generated in all. Every primer offered 3.47 markers on average. The molecular phylogenetic tree by UPMGA method showed that main parents were divided into five groups at genetic similarity coefficient 0 69. The parents between groups have great genetic differentiation relatively. The extent of indica component value was from 0 12 to 0.48 in the parents.

Key words: hybrid rice, main parents, molecular marker, genetic differentiation, indica component degree

摘要： 利用微卫星（SSR)分子标记对北方杂交粳稻骨干亲本进行了遗传差异鉴定和籼性程度分析。以15对SSR引物对模板DNA扩增产生52条多态性标记，每个引物平均提供3.47个标记信息。用平均距离法（UPMGA）进行聚类分析，骨干亲本在相似系数0.69处可分成5组，各组间亲本的遗传差异相对较大；23个骨干亲本的籼性程度参数值的变化幅度为0.12～0.48。

关键词: 杂交水稻, 骨干亲本, 分子标记, 遗传差异, 籼性程度