Abstract:

Iner-simple sequence repeat (ISSR) markers were used to investigate the genetic diversity and genetic relationships among 22 germplasms of Phalaris arundinacea from different regions. The aim of this study was to provide the scientific basis for the effective utilization of the reed canarygrass germplasm. Ten ISSR primers with clear bands and good polymorphism generated 160 discernible DNA bands, of which 145 were polymorphic loci. The main indexes were:The average percentage of polymorphic band (PPB) was 90.62%; effective number of alleles (Ne) was 1.5263±0.0874; Nei's gene diversity (He) was 0.3063±0.0436; and Shannon's information index(I) was 0.4601±0.0646. The genetic similarity coefficient between germplasms ranged from 0.4938 to 0.8250. Unweighted pair-group method with arithmetic means(UPGMA) clustered 22 materials into two groups at Gs 0.58. Group one was consist of No.A-1 and No.A-2 two materials, and group two was composed of residual twenty materials. The 20 reed canarygrass materials in the second group were divided into four subgroups at Gs 0.71. Subgroup one was consist of nine reed canarygrass materials from Russia' northwestern and China's Mid-western regions; subgroup two was composed of six reed canarygrass materials from Russia' Mid-Eastern and China's Zhenjiang regions; subgroup three was included three reed canarygrass materials from China and America regions; and subgroup four was composed of two reed canarygrass materials from China Tongliao regions. It indicates that the genetic diversity of reed canarygrass germplasm could be evaluated by ISSR markers effectively. Genetic differentiation has some correlation with geographic origin of reed canarygrass accessions, but Genetic Clustering was inconsistent with geographic origin. These results provide valuable references for protection, utilization and variety selection of the reed canarygrass germplasm resources.

Key words: Phalaris arundinacea, Germplasm resources, Genetic diversity, ISSR markers, Cluster analysis

摘要：

采用ISSR（inter-simple sequence repeat）分子标记法对来自不同地域的22份虉草（Phalaris arundinacea L.）种质材料进行遗传多样性和亲缘关系分析，为虉草种质资源有效利用提供理论依据。用10条扩增清晰、多态性较好的引物，共扩增出160个位点，其中多态性位点145个，多态性位点百分率（PPB）为90.62%，平均有效等位基因数（Ne）为1.5263±0.0874，平均Nei's基因多样性（H）为0.3063±0.0436，平均Shannon多样性信息指数（I）为0.4601±0.0646，种质间遗传相似系数（Gs）为0.4938～0.8250。通过UPGMA（unweighted pair-group method with arithmetic means）聚类方法对22份虉草材料进行聚类分析。结果表明，在Gs为0.58时可将22份虉草材料分为两大类群，第Ⅰ类群包含A-1和A-2共2份材料，其余材料均归为第Ⅱ类群；在Gs为0.71时可将第Ⅱ类群的20份材料细分为4个亚类群，第Ⅰ亚类群包含9份材料，主要来自俄罗斯西北部和中国中西部地区；第Ⅱ亚类群包含6份材料，多数来自俄罗斯中东部和中国镇江地区；第Ⅲ亚类群包含3份材料，来自中国和美国；第Ⅳ亚类群包含2份材料，来自中国通辽地区。用ISSR标记技术可有效揭示虉草种质资源的遗传多样性，试验中来自不同地域的22份虉草种质材料遗传多样性较为丰富。试验结果表明虉草种质资源遗传分化与地理来源有一定的相关性，但遗传聚类与地理来源不完全一致。

关键词: 虉草, 种质资源, 遗传多样性, ISSR标记, 聚类分析