中文摘要：

本研究利用SCoT标记对96份柳枝稷种质的亲缘关系和遗传变异进行了研究。筛选出20条引物对96份供试材料进行PCR扩增，共获得445条带，其中多态性条带402条，平均多态性条带比率（PPB）达90．31％，多态性信息含量（PIC）为0．166～0．410，平均值为0．332，标记指数（MI）为10．20。遗传相似系数（GS）为0．498～0．912，平均值为0．688。表明SCoT标记能够揭示柳枝稷种质间的遗传变异。通过UPGMA分析表明，96份种质资源聚为高地型和低地型两大类。经POPGENE1．32软件分析结果显示：96份柳枝稷基因多样性指数（H）为0．285，Shannon指数（I）为0．431，表明供试的种质间遗传多样性丰富，遗传多样性水平高。经AMOVA1．55方差分析揭示：96份柳枝稷生态型内的遗传变异占总变异的72．85％，生态型间遗传变异占总变异的27．15％，结果表明ScoT可用于柳枝稷遗传多样性研究，该研究结果可为柳枝稷种质资源的进一步开发利用提供重要信息。

英文摘要：

The genetic variation and relationship of 96 switchgrass germplasms were analyzed by SCoT molecu- lar markers. 20 SCoT primer pairs were used to amplify SCoT fragments for 96 switchgrass germplasms. The primers generated a total of 445 bands among which 402 bands were found to be polymorphie, with an average of 90. 31%. The value of locus polymorphism information contents （PIC） ranged from 0. 166 to 0. 410, with an average of 0. 332. Marker index was 10.20. The genetic similarity coefficient among the germplasms ranged from 0. 498 to 0. 912, and the average content was 0. 688 ,indicating that the genetic variation could be revealed using SCoT markers. 96 switehgrass germplasms were clustered into upland and lowland groups by the cluster analysis. The results of POPGENE version 1.32 analysis showed that the genetic diversity index（H） and Shannon index （I） was 0. 285 and O. 431, respectively which indicating that there was comparatively great genetic diversity and high genetic variation among the switchgrass germplasms. Analysis of molecular variance （AMOVA 1.55 ） indicated that 72.85% of total variability came within populations level,while 27.15% came among populations level. The results indicated that SCoT markers were feasible and effective to analyze the genetic diversity of switchgrass and the results would facilitate the exploitation and utilization of switchgrass germplasms.