| Armeniaca sibirica with a set of ecological,economic and social benefits plays an important role in the construction of ecological economy in Western Liaoning,but the "bottleneck" restricting the development of the industry is the yield of fruit is low and unstable.In order to provide scientific basis for the breeding research,the phenotypic diversity of 16 quality traits and 22 quantity traits of Armeniaca sibirica clones in Armeniaca sibirica Germplasm Resources Garden of Beipiao Tree Breeding Center, Liaoning province,was overly estimated.Also,genetic diversity was analyzed based on the 98 screened SSR markers by scanning the whole genomes of the clones.On the basis of these,association analysis between phenotypic traits and SSR markers was totally undertaken.The summarized results are as follows.(1)The Armeniaca sibirica clones showed abundant diversity on 16 quality traits.The observation of quantity traits indicated that the differentation of economic traits among clones was extremely significant,showing high potential for breeding high quality varieties in Armeniaca sibirica.The main basis of the distinction between Armeniaca sibirica clones could be single fruit weight,single kernel weight,single almond weight,length of young shoot,width of young shoot,petiole length,petiole width,tree height and stem diameter.The repeatabillities of fruit,kernel,almond and flower were higher,while those of crown width and stem diameter lower.By principal component analysis with Q cluster analysis of 22 quantitative traits,66 Armeniaca sibirica clones were divided into 11 categories,which provided a reference for evaluating the germplasm resources.(2)The average number of alleles per locus(NA) and the number of effective alleles(NE) of 98 loci showed high level of polymorphism in SSRs,populations,and provenances,constituting 9.910 and 5.445 respectively,and the polymorphism information content(PIC) was 0.675,which indicated that these markers had high polymorphism in the population.Genes flow among the Armeniaca sibirica clones,but genetic differentiation coefficient(FST) showed 15.4% of the provenances gene frequency differentiation.66 Armeniaca sibirica clones were clustered into 4 groups by application of unweighted pair arithmetic average method(UPGMA).The clustering result and provenance classification were very significantly correlated.Clustering result of provenances reflected geographical distribution and the genetic diversity from high to low was followed by Liaoning Beipiao,Liaoning Kazuo,Liaoning Chaoyang and Inner Mongolia Aohan.The correlation between geographical distances and genetic distances of the provenances was significant,that of individuals was very significant,indicating that geographical isolation plays an important role in the evolution of Armeniaca sibirica.(3) By scanning Armeniaca sibirica genomes using 98 SSRs,we found extensive linkage disequilibrium (D>0.5,p<0.01) in Armeniaca sibirica,but the overall level was low (r2<0.5, p<0.01).Population structure analysis based on STRUCTURE showed that the 66 Armeniaca sibirica clones could be divided into 4 subgroups.Chi-square test of the matrix based on the mathematical model and provenance classification result was very significant,but that of phenotypic traits was not significant.Classification based on Nei’s genetic distance and mathematical model was completely anastomotic.Association analysis between phenotypic traits(16 quality traits and 31 quantity traits) and 98 polymorphic loci was undertaken by using the general linear model (GLM) and mixed linear model (MLM),the result showed that 16 loci respectively associated with 8 traits and the average phenotypic variation of associated alleles was summarized.In this paper,the summarizing of the phenotypic effects and the carriers of the alleles underlying associated loci,would provide reference for linkage mapping,molecular marker assisted selection,selecting parents for high generation seed orchard and molecular designed breeding in Armeniaca sibirica. |
PDF Full Text Request