基于SSR标记的不同染色体数目割手密资源遗传多样性分析

Genetic Diversity Analysis of Saccharum spontaneum L. with Different Chromosome Numbers Based on SSR Markers

甘蔗野生种割手密抗逆性强,是一种重要的甘蔗种质资源。本研究用23对简单重复序列标记(SSR)引物及优化后的降落PCR体系,对采自中国、缅甸、尼泊尔、印度4国不同地区的100份割手密材料(染色体数目2n=40~106),进行了遗传多样性分析。结果表明供试材料均显示出良好的多态性:共扩增出937条带,其中有920条多态性标记,多态率达97.77%,多态信息量(PIC)为89.87%;供试材料的遗传相似性系数在0.41~0.94之间,平均为0.68。经UPGMA聚类将供试材料划分为4个类群10个亚类,其聚类方式呈现出明显的区域性,群体可分为高海拔地区割手密(云南,贵州,四川,西藏,尼泊尔)、低海拔沿海地区割手密(福建,广东,海南)、缅甸地区割手密,并对割手密的染色体数、分布范围和亲缘关系进行了讨论。

Saccharum spontaneum is an important kind of germplasm resources for sugarcane breeding with its strong stress resistance. 100 S. spontaneum clones collected from China, Myanmar, Nepal and India were chosen in this study, and the chromosome numbers were 2 n =40 -106.23 pairs of SSR primers and the optimized touchdown SSR-PCR were utilized in genetic diversity analysis of the 100 clones. The results showed that the 100 S. spontaneum clones all presented a rich polymorphism. 937 bands were amplified, in which 920 were polymorphism markers, with the polymorphic rate of 97.77%, and the polymorphism information content（PIC）was 89.87%. The genetic similarity coefficient of the test materials was between 0.41-0.93, with an average of 0.68.The UPGMA cluster analysis indicated that the 100 materials could be divided into 4 groups and 10 subgroups,and the clustering pattern presented significant regional characteristics. These groups could be divided into the‘Plateau S. spontaneum＇（Yunnan, Guizhou, Sichuan, Tibet, Nepal）,‘Coastal S. spontaneum＇（Fujian, Guangdong,Hainan）, and‘Burma S. spontaneum＇. Also, the chromosome number, distribution range and relationship of S.spontaneum were discussed.