杂交稻部分不育系与恢复系的SSR分类

选用分布于水稻(Oryza sativa L.)12条染色体上的36对SSR(simple sequence repeats)引物，分析了5个光温敏核不育系、7个细胞质雄性不育系及54份来自不同生态类型恢复系或品种的遗传差异。在供试材料中共检测出300条多态性片段，平均每对SSR引物检测到8.33条。分析结果表明，(1) SSR标记明确地把供试的66份水稻材料中的65份区分开来，和已知系谱的亲缘关系多数吻合，与表型性状聚类结果也有一定的相似性。(2) 以GD=0.73为标准，可准确地将籼稻、粳稻、野生稻三大类区分开；以GD=0.63为标准，又可区分出籼稻大类中带有粳稻或野生稻血缘的品种。表明SSR标记对籼稻、粳稻、野生稻品种的分类灵敏度高、结果可靠；并筛选出可用于鉴别水稻籼粳类型的10对特异性引物。(3) 以GD=0.56为标准，将供试材料划分在8个生态类型中，为生产上杂优组合亲本的选配提供了一些有益的参考。同时，生产上常用的一些杂交稻亲本划分在不同的生态类型中，表明强优势组合亲本间的遗传差异一般较大。

Classification for Some Sterile Lines and Their Restorers of Hybrid Rice with SSR Markers

Abundant heterosis is manifested from the cross of two genetically diverse parent lines.Therefore,it is essential to reveal genetic relationships among varieties with unknown pedigree.In the present study,genetic divergences among 66 rice(Oryza sativa L.) varieties,including 5 photoperiod/thermo-sensitive genic male sterile lines,7 cytoplasmic male sterile lines,53 restorers and one wild rice variety,were analyzed by using 36 SSR(simple sequence repeats) primer pairs which disperse on 12 chromosomes.A total of 300 polymorphic bands were detected among 66 varieties,and on average(8.33) distinguishable bands were observed after amplification with each primer pair.Genetic divergences between all possible pairs of varieties were defined by Nei M method with genetic distance(GD),calculated from SSR data by the equation(GD=)-ln2M_(XY)/(M_(X) M_(Y))],where M_(XY) was the total number of bands common to varieties X and Y,and M_X and M_Y were the total number of bands present in X and Y respectively.66 cultivars were clustered based on GD by Unweighted Pair Group Method using Arithmetic Average (UPGMA).The results were concluded as follows:(1) Sixty-five out of sixty-six varieties were distinguished obviously.Different ecotypes were also defined using SSR markers,which were consistent with the relationships of their pedigrees,and were similar with the result of phenotype analysis.(2) Indica,japonica and wild rice were discriminated based on GD=0.73,and some indica cultivars bearing japonica or wild rice consanguinity were discriminated based on GD=0.63,indicating that SSR markers are sensitive and precise for classification on indica,japonica and wild rice.Otherwise,ten specific primers were screened and selected to identify subspecies between indica and japonica.(3)Twelve male sterile lines and more than fifty restorers were divided into eight ecotypes based on GD=(0.56),and many parents of hybrid rice used in large scale were classified into multiple ecotypes,suggesting there are great genetic divergences between the parents of elite hybrid rice.Parents' selection of hybrid rice will get benefit from the classification on both male sterile lines and restore lines.