西南地区野生狗牙根种质资源的SSR与AFLP联合分析

Joint analysis of SSR and AFLP on wild Cynodon dactylon germplasm of southwest China

为了制定科学的资源保护策略、促进其开发利用以及新品种的选育,对西南地区55份野生狗牙根材料,联合采用SSR和AFLP方法分析其遗传多样性。通过进行引物筛选,筛选出有效引物组合18对和11对;SSR和AFLP扩增总条带353和626条,多态性条带267和592条,平均每对引物扩增出多态性条带19.61和53.83条,多态性位点百分率为75.10%和94.57%。聚类分析表明GS=0.806时,可将所有供试材料分成6个组群,当GS=0.82时,可将第VI个组群分成4个小组,当GS=0.836时,第VI组群中第3小组的14个材料分为3个组群基于Shannon多样性指数,类群内的遗传变异占总变异的67.41%,类群间的遗传变异占总变异的32.59%。基于Nei氏无偏估计的遗传一致度的聚类分析表明,各生态地理类群间的遗传分化与其所处的生态地理环境具有一定的相关性。通过两种标记的相关性分析,表明SSR和AFLP标记之间具有显著的相关性,而且相关性较高,证明供试材料的聚类和其生态地理环境间有一定的相关性;采用SSR和AFLP两种联合分析,结果会更加合理和有效。

In order to guide the introduction and utilization of germplasm resources, to provide a scientific basis for molecular marker-assisted breeding and to select parents for breeding programs accurately, in the study SSR and AFLP markers were employed to investigate the genetic diversity and relationships of 55 wild accessions of Cynodon dactylon of Southwest China. By the screening of primer, 18 pairs of SSR and 11 pairs of AFI.P primers were select ed and used for the present study. Eighteen primer pairs of SSR and eleven primer pairs of AFI.P produced a total of 353 and 626 bands,including 267 and 592 polymorphic bands, averaged 19.61 and 53.83 polymorphic bands per prim- er pair. The percentages of polymorphic bands in average were 75.10% and 94.57%. By the analysis of the cluster, when the GS was 0.806, the 55 accessions were classified into six major groups, GS was 0.82, the VI of the group was divided into four groups,GS was 0.836, group 14 material in Part VI of the group was divided into three groups. Ge- netic differentiation between or within six eco-geographical groups of C. dactylon was estimated by Shannon＇s diver- sity index,and the results showed that 67.41% genetic variance existed within group, and 32.59 % genetic variance was among groups; Based on Nei＇s unbiased measures of genetic identity, UPGMA cluster analysis of six eco-geo- graphical groups of C. dactylon indicated that there was a correlation between genetic differentiation and eco-geo- graphical habits among the groups. Further indicated that using the both markers to analysis of the genetic diversity of C.dactylon was more reasonable and effective.