Analysis Of Genetic Relationship And Structure Of Chinese Jujube By SSR Markers

Jujube(Ziziphus jujuba Mill.)is a Chinese native Rhamnaceae species.It has strong adaptability,high yield,high nutritional and medicinal value,and is an important fruit tree in China.Chinese jujube is rich in germplasm resources and widely distributed.The northern region is the main distribution area of Chinese jujub germplasm,including the accesses as dry,fresh(eurythermal,cold resistant)and both.The south region is the main distribution area of Chinese fresh jujube germplasm of high temperature or high temperature and high humidity.At present,the research reports on Chinese jujube are mostly concentrated on the northern germplasm,and there are few reports on the study of the southern germplasm.In this study,SSR markers were used to analyze the genetic relationship,genetic diversity and population genetic structure of Sichuan jujube germplasm,to lay the foundation for effective utilization of jujube germplasm resources of the southern.The main results and conclusions are as follows:1.The percentage of polymorphic loci of 15 microsatellite loci was 100%.Polymorphism information content(PIC)ranged from 0.3557 to 0.8200(with an average of 0.6677).The 15 primers had moderate or high polymorphic and was suitable for the genetic relationship analysis of 33 cultivars from Sichuan province.2.The genetic diversity of 33 cultivars was analyzed by the 15 primers.The results were as follows: A total of 111 alleles(Na)were amplified.The number of alleles per locus ranged from 2 to 14,with an average of 7.4.Expected heterozygosity(He)and observed heterozygosity(Ho)ranged from 0.463 to 0.839 and 0.364 to 0.848,with averages of 0.711 and 0.624,respectively.Shannon's information index(I)ranged from 0.655 to 2.089,with an average of 1.509.33 accessions of Chinese jujube cultivars showed abundant genetic diversity.3.UPGMA clustering results can separate 30 from 33 jujube cultivars completely.There were close genetic relationship of Zhandong2 hao,Dongzao and Shucuizao.Luojiangtiaoyuanzao,Longquanyouzao,Qishanmizao and Changqiumizao genetic similarity coefficient was 1.00,which belongs to the synonym.Wulongzhuyaozao and other Chinese Jujube Cultivars(lines)has far genetic relationship.4.Except JSSR93(PIC=0.0772)and JSSR198(PIC=0.0421),21 microsatellite loci PIC ranged from 0.2576 to 0.8410(with average of 0.5284).The primers were moderate or high polymorphic and suitable for analysis population genetic structure of Chinese jujube germplasm.5.We detected the population genetic structure and genetic differentiation of 297 jujube accessions by 21 primers.The results showed that the I value ranged from 0.111 to1.908(with an average of 1.142).The He value ranged from 0.043 to 0.835(with an average of 0.578).The 297 materials had abundant genetic diversity.6.STRUCTURE and NJ cluster analysis results showed that 9 species can be divided into four groups.Zhanshanmizao 1 hao,Zhanshanpingguozao and Zhanshandaguozao cultivar groups were classified into the first group.Luojiangtiaoyuanzao,Longquanyouzao,Qishanmizao and Changqiumizao were classified into the second group.Wenchuanzao was classified into the third group.Shucuizao was classified into the forth group.7.The results of molecular variation analysis(AMOVE)and principal component analysis(PCA)showed that there were high genetic differentiation(G'st=0.521,Nm=0.432)in Sichuan jujube population.