Abstract: To study the genetic differences of Stenotaphrum helferi Munro ex Hock. F. from different geographical sources， 13 S. helferi accessions from different countries were used to analyze their genetic relationship by using PCR-based SRAP （Sequence related amplified polymorphism） molecular markers in this study. The results showed that 21 primer pairs from the original 100 primer pairs were selected based on the polymorphism， clarity and reproducibility of the bands. A total of 161 bands were amplified by 21 primer pairs from 13 accessions with an average of 7 bands per primer pair， and 161 （100.00%） out of them were polymorphic. The genetic similarity co-efficient （GSC） among the 13 accessions ranged from 0.4805 to 0.9286 with an average of 0.6452. Cluster analysis conducted by the unweighted pair-group method with arithmetic average （UPGMA） separated the 13 accessions into 4 groups when the genetic similarity coefficient was 0.6930. Principal component analysis divided the 13 accessions into 5 groups. The results indicated that the genetic diversity of S. helferi accessions was rich， which laid a foundation for the identification and evaluation of S. helferi accessions and molecular marker-assisted breeding.

Key words: Stenotaphrum helferi, SRAP, Molecular makers, Genetic diversity

摘要： 为了研究不同地理来源钝叶草种质资源间的遗传差异，本研究以13份来自不同国家的钝叶草种质资源为研究对象，利用SRAP标记对其进行遗传多样性分析。结果表明：从100对引物组合中筛选出了21对有多态性条带、且扩增条带清晰稳定的引物。利用这些引物对钝叶草种质进行扩增，共扩增获得161条条带，且均是多态性条带，多态性百分率为100.00%，平均一对引物能检测到7条条带，扩增范围为4~10条。遗传相似性系数为0.4805~0.9286，平均值为0.6452。利用UPMAG法在遗传相似性系数为0.6930时将13份钝叶草种质分为4个类群。主成分分析可将其分为5个类群。本研究结果表明13份钝叶草种质资源的遗传多样性处于上等水平，SRAP标记能有效地评价钝叶草种质的遗传差异，为钝叶草种质的开发利用提供依据。

关键词: 钝叶草, SRAP, 分子标记, 遗传多样性