基于SSR分子标记的油棕遗传多样性分析
Genetic diversity of Elaeis guineensis Jacq. based on SSR markers
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摘要: 目的应用SSR分子标记对8个油棕品种进行遗传结构及多样性分析,以期通过分析具有高杂合度油棕品种的遗传结构来辅助育种.方法利用SSR分子标记及PCR银染显色技术筛选多态性引物,分析8个油棕品种的等位基因频率(P)、观测杂合度(Ho)和期望杂合度(He),计算每个转座子的平均等位基因(Na)、每个多态转座子的平均等位基因数(Na/pl)及有效等位基因数(Ne),计算固定指数(Fis)和F-统计量值(Fit和Fst),并基于遗传距离对8个油棕品种进行聚类分析.结果开发出27对多态性SSR引物,从中选取15对结果较好的多态性引物对油棕大样本进行检测,挖掘出57个等位基因(Na),平均每个转座子的Na为3.8个,表明8个油棕品种的遗传变异较明显.平均有效等位基因数(Na)和期望杂合度(He)分别为0.6248和0.5902.此外,发现一个高水平的种群分化,F-统计量值(Fst)变化范围为0.1029~0.6010,平均为0.3664.利用多态性SSR分析8个油棕品种的遗传距离,结果发现品种1和品种3的遗传距离最远(1.674),品种3和品种5的遗传距离最近(0.065).结论8个油棕品种的多态性相对丰富,物种间杂交程度较小,物种亲缘关系较远,遗传多样性良好.Abstract: ObjectiveThe present study conducted genetic structure and genetic diversity analysis on eight Elaeis guineensis Jacq. varieties using SSR molecular marker, in order to provide references for breeding through analyzing genetic structure of E. guineensis Jacq. varieties with high levels of heterozygosity. MethodUsing SSR molecular marker and PCR silver-stain technique, the researchers analyzed allele frequencies (P),observed heterozygosities (Ho) and expected het-erozygosities (He) , calculated mean number of alleles per transposons (Na) , mean number of alleles per polymorphic transposons (Na/pl) and number of effective alleles (Ne). Fixation index (Fis) and F-statistic values (Fit and Fst) were also calculated. Clustering analysis on eight E. guineensis Jacq. varieties was conducted based on genetic distance. ResultTwenty-seven pairs of polymorphic SSR primers were developed,fifteen pairs of polymorphic primers with good results were selected for testing E. guineensis Jacq. large sample. Fifty-seven alleles(Na) were detected,and Na per transposons was 3.8 on average, which showed that the genetic variation of eight E. guineensis Jacq. varieties was obvious. Average effective al-leles (Ne) was 0.6248 and expected heterozygosity (He) 0.5902. A high-level population differentiation was found, F-statistic value(Fst) ranging from 0.1029 to 0.6010 and being 0.3664 on average. Polymorphism SSR was applied to analyze genetic distance of the eight E. guineensis Jacq. varieties. The results indicated that genetic distance between Variety 1 and Variety 3 was the longest(1.674), and genetic distance between Variety 3 and Variety 5 was the shortest(0.065). Con-clusionThe eight E. guineensis Jacq. varieties enjoy abundant polymorphism, small hybridization degree between species, far species polygenetic relationship and sound genetic diversity.