利用荧光SSR分析中国糜子遗传多样性

Analysis of Genetic Diversity in Common Millet (Panicum miliaceum) Using Fluorescent SSR in China

分析糜子种质资源的遗传多样性,有助于了解糜子起源与进化,可为糜子优异种质发掘及资源高效利用提供理论基础。本研究利用15个糜子特异性荧光SSR标记检测来源于中国11个省(区)的132份糜子种质资源,检测到107个等位变异,每个位点等位变异数为2~14个,平均7个;基因多样性指数为0.0936~0.8676,平均0.5298;多态性信息含量为0.0893~0.8538,平均0.4864。采用遗传距离的聚类将试验材料分为4类,类群I来自东北春糜子区,类群II来自黄土高原春、夏糜子区,类群III来自于北方春糜子区,类群IV来自北方春糜子区和黄土高原春、夏糜子区。分析模型的遗传结构表明,中国糜子资源来自4个(东北地区、黄土高原、北方地区和西北地区)基因库,与基于遗传距离的聚类结果基本一致,均与材料的地理起源相关。糜子遗传变异丰富,主要存在于糜子材料间。该结果从分子水平上准确揭示了中国糜子的遗传多样性。

Understanding of the genetic diversity of common millet germplasm resources is a basis of research on its origin and evolution, as well as the effective utilization of elite germplasm. In this study, we analyzed the genetic diversity of 132 common millet accessions collected from 11 provinces of China using 15 millet-specific fluorescent-labelled simple sequence repeat（SSR） markers. A total of 107 alleles were detected with 7 alleles per locus ranging from 2 to 14. The expected heterozygosity ranged from 0.0936 to 0.8676 with the mean value of 0.5298. The polymorphism information content（PIC） ranged from 0.0893 to 0.8538 with the mean value of 0.4864. The 132 accessions were clustered into four groups according to genetic distance between acces-sions, which showed geographic and eco-regional distributions. Group I is a collection of germplasm from spring-sowing area of Northeast China, group II is composed of partial accessions from the spring and summer-sowing areas of Loess Plateau, group III is composed of partial accessions from the spring-sowing area of Northern China, and the remaining accessions comprises Group IV with geographic overlaps to groups II and III. Model-based genetic structure analysis indicated that the genetic resources of Chinese common millet were from four gene pools in Northeast, Loess Plateau, Northern, and Northwest China. Obviously, this result was very similar to that of clustering analysis, showing the importance of geographical relationship. Rich genetic variations were also found in Chinese common millet resources, mainly from different accessions. The above results provide an overall evaluation of genetic diversity of common millet in China at a molecular level.