Genetic Diversity Analysis And SSR Locus Mining Of Main Economic Traits In Zizyphus Jujuba Var.Spinosa

Zizyphus jujuba var.spinosa is a unique eco-economic tree species in China,which is widely distributed and has broad development prospects.Because it is in wild state for a long time,affected by natural environmental factors and human activities,resulting in unreasonable development and utilization of Zizyphus jujuba var.spinosa resources.In this paper,Zizyphus jujuba var.spinosa germplasms from western Liaoning Province were used as the research objects,and 32 polymorphic SSR markers were used to analyze the association and phenotypic effect with 17 main economic traits.The specific loci associated with different traits were mined,and the carrier materials with excellent alleles were obtained.At the same time,the fruit quality of the selected typical carrier materials was analyzed to provide a theoretical basis for accelerating the breeding of excellent parents and rational development and utilization of Zizyphus jujuba var.spinosa resources.The main research results are as follows :(1)The variation of main economic characters was abundant,the average coefficient of variation was 27.82 % and the average diversity index was 1.939.The polymorphism level of SSR markers was high.A total of 321 polymorphic alleles were amplified from the genomic DNA of the tested germplasm,and the average polymorphism information content(PIC)was 0.739 > 0.5.Population structure analysis divided tested germplasms into four groups,and most of them had pure genetic background in each group.SSR primers had low linkage disequilibrium in Zizyphus jujuba var.spinosa germplasm.(2)In the correlation analysis,21 SSR loci detected by the GLM model were significantly correlated with 17 traits(P < 0.05),and the explained rate of variation was15.35 %–69.14 %.17 SSR loci detected by MLM model were significantly associated with16 traits,and the explained rate of variation was 0.82 %–75.37 %.Two models were used to detect 16 association loci associated with 16 traits.In the phenotypic effect value analysis of the allelic fragments at the association sites,29 excellent allelic variations and 11 vector materials associated with the fruit,kernel and kernel of Zizyphus jujuba var.spinosa were excavated with the maximum efficiency and maximum efficiency reduction.(3)The difference analysis of fruit quality traits of Zizyphus jujuba var.spinosa typical carrier materials showed that the contents of VC,total flavonoids and total phenols in flesh of LW91 were higher,the kernel rate of LW94 was the largest,the fruit of LW95 was the largest,the contents of soluble solids and titratable acid in flesh were the highest,the contents of total flavonoids and total alkaloids in kernel of LW103 were the highest,and the content of total saponins in kernel was higher.(4)The cumulative contribution rate of principal component analysis for fruit quality traits of Zizyphus jujuba var.spinosa was 92.051 %.Comprehensive principal component score and fuzzy mathematics membership function evaluation results,the appearance and internal quality of Zizyphus jujuba var.spinosa LW103 were excellent,which was the best typical carrier material.