Genetic Diversity Of Agronomic Traits And Association Analysis With SRAP Markers In Worldwide Germplasm Collection Of Prairie Grass

Prairie grass(Bromus catharticus)is a kind of high quality grass,with long growth period,fast growth,strong regeneration ability and well adaptability.Meanwhile,B.catharticus shows broad prospect of application in soil and water conservation and ecological management.In view of this,the development of B.catharticusgermplasm,genetic improvement and studing the population genetic relationship and the genetic control of important traits is important in theory and practice.In order to accelerate breeding process of B.catharticusand explore the genetic diversity and genetic relationship among B.catharticusresources,SRAP molecular markers were used to study the genetic diversity and group structure among 80 B.catharticusmaterials around the world,and the association analysis method was used to detect the molecular marker associated the important agronomic traits.1.Trait differences and correlation analysis showed that:9 traits performance of 80 oats B.catharticus showed very abundant variation,these traits variation coefficients are higher,which indicate genetic background of the material complex and variation abundant.Coefficient of variation of Dry matter yield is the largest.Correlation analysis for 9 traits,steam diameter and length of first internode was significantly positivecorrelation with others,length of second upper leaf and width of flag leaf was highest significantly correlated.2.Genetic diversity and population structure analysis shows that 460 distinct PCR bands were amplified in total of 47 primers.Among the 460 bands amplified,398 were polymorphic,and the polymorphic rate was 85.9%.The Dice genetic similarity coefficients among those germplasm ranged in 0.5516-0.9825 with average of 0.7919,which suggested that there were abundant genetic diversity among the B.catharticus germplasm,and rich genetic variance.The population structure analysis revealed 78(97.5%)B.catharticus were with single genetic components,and the rest(2.5%)were with mixed genetic components.3.Correlation analysis showed that linkage disequilibrium exited between sites,population genetic structure analysis revealed that 80 germplasm formed by the three sub-groups,there are 64 sites associated with the trait,some marker locus associated with two or more traits,may be the result of pleiotropic effects,most of the traits associated with multiple marker sites,may be the result of multigenic effect.