小桐子25个无性系遗传多样性的SRAP分析

为评价25个小桐子无性系的遗传多样性和亲缘关系，采用SRAP标记技术从41对SRAP引物中筛选出31对多态性高、稳定性好的引物，对上述材料的基因组DNA进行研究。结果表明：每对引物组合产生10~28条谱带，其中多态性条带142条，占总带数的25.4%。25个无性系间的相似系数为0.409~ 0.951之间，平均相似系数为0.714。其中，3号与7号的相似系数最大，亲缘关系最近；6号与11号的相似系数最小，亲缘关系最远。UPGMA聚类分析结果显示，供试材料在相似系数为0.72处被划分为5个类群。25个无性系中有7个无性系扩增出了各自的特征谱带，而仅凭各自的这1条特征谱带即可将7个无性系与其他材料区分开，这说明SRAP标记可用于小桐子种质的分子鉴定与群体遗传结构的研究。通过上述研究得出结论：虽然25个无性系的遗传多样性不丰富，但是在分子水平上各有差异。

Genetic Diversity Analysis among 25 Clones of Jatropha curcas by SRAP Markers

To evaluate the genetic diversity and relationship among 25 clones of Jatropha curcas, the SRAP marker technology was used to analyze the difference of genomic DNA of above materials. The results showed that, 31 highly polymorphic and stable primer pairs were selected from 41 pairs of SRAP primer. With each primer combination generating 10-28 bands, 142 polymorphic bands were detected, accounting for 25.4% of the total. The similarity coefficient of the 25 clones was 0.409-0.951, with the average similarity coefficient of 0.714. In all clones, number 3 and number 7 had the greatest similarity coefficient, while number 6 and number 11 had the minimum one. 25 Jatropha germplasms were divided into five groups on the similarity level of 0.72. 7 clones had their respective specific bands, which could distinguish them from others. It is demonstrated that SRAP markers can be used for variety identification and population genetic construction of Jatropha. The conclusion is that, although the genetic diversity of 25 clones is not rich, they are different from each other on the molecular levels.