Abstract: White clover (Trifolium repens L.) is an important perennial legume forage with high productivity and quality. To analyze the genetic diversity of the new variety of white clover introduced from abroad. Therefore, in this study, Simple Sequence Repeats (SSR) molecular markers were used to identify 13 white clover cultivars and construct DNA fingerprints, which would be directly and effectively used for white clover cultivars identification. The results showed that 115 different bands were amplified from 20 pairs of SSR primers, and 104 of which were polymorphic (90.4%). Meanwhile, the Polymorphism Information Content (PIC) ranges from 0.198 to 0.455 with an average of 0.333. AMOVA analysis showed that 49% of genetic variation occurred among cultivars and 51% occurred within cultivars. The results of cluster analysis and principal component analysis showed that among the 13 cultivars, ‘Super Haifa’ and ‘Haifa’ had the closest genetic relationship, while ‘Miligro’ and ‘Klondike’ had a far genetic distance. The DNA fingerprint constructed with six representative primers including gtrs1164, gtrs573, gtrs541, gtrs171, gtrs536 and gtrs173, have strong identification ability and could be used to effectively identify 13 white clover cultivars.

Key words: Trifolium repens L., SSR, Genetic diversity, DNA fingerprinting

摘要： 白三叶（Trifolium repens L.）是一种多年生冷季型豆科牧草，因其具有产量高、品质优良等特点，已成为我国西南地区重要的优质牧草。为分析国外引进的白三叶新品种的遗传多样性，本研究利用简单重复序列（Simple sequence repeats，SSR）分子标记对13个白三叶品种进行品种鉴定及DNA指纹图谱的构建，以期利用此方法直接、有效的鉴定和区分白三叶品种。结果表明：20对SSR引物共扩增出115条不同的条带，其中多态性条带104条（90.4%）；同时所有引物的多态信息含量（Polymorphism information content，PIC）范围为0.198~0.455，平均值为0.333；AMOVA分析表明，49%的遗传变异发生在品种间，51%发生在品种内部；聚类分析和主成分分析的结果表明，13个品种的亲缘关系中，'超级海法’和'海法’的亲缘关系最密切，'米莉格’和'克朗德’的遗传距离较远；利用6种具有代表性的引物gtrs1164，gtrs573，gtrs541，gtrs171，gtrs536和gtrs173构建的DNA指纹图谱具有较强的识别能力，可将13个白三叶品种有效的鉴定区别开来。综上所述，本试验所选用的6对引物具有良好的多态性，可用于白三叶品种的指纹图谱构建。

关键词: 白三叶, SSR分子标记, 遗传多样性, DNA指纹图谱