Genetic diversity analysis of microsatellite DNA of Apis cerana in Jiangxi

【Objective】To clarify the level of genetic diversity and differentiation regular patterns of Apis cerana under habitat conditions in Jiangxi, and provide theoretical basis for promoting the protection and utilization of the genetic resources of A. cerana in Jiangxi, as well as the protection and rational layout of A. cerana genetic resources in China.【Method】A total of 37 microsatellite markers were selected to analyze the genetic characteristics, genetic diversity and genetic differentiation of 704 populations of A. cerana from 10 representative sites in Jiangxi. Excel Microsatellite Toolkit 3.1 was used to calculate the observed heterozygosity(Ho), expected heterozygosity(He), number of alleles(Na) and polymorphic information content(PIC). PopGene 1.31 was used to calculate the effective allele number(Ne) and Shannon index(I), and GenAlEx 6.5 and R 4.0.3 were used to carry out principal coordinate analysis(PCoA) and principal component discriminant analysis(DAPC) respectively. Genetic differentiation index(F_st) between sample sites was analyzed using Genepop on Web online software. Gene flow(Nm) was calculated using F_st=1/(1+4Nm), and UPGMA dendrogram was constructed using POPTREE2.【Result】A total of 374 alleles were detected from 704 populations of A. cerana at 10 sampling sites in Jiangxi using 37 microsatellite markers. Among them, 21 microsatellite markers(AP243, BI278, AP249, AT185, BI225, AC139, Ap313, AT004, AC045, K0715, AC011, AP189, BI314, Ap085, AT101, 244T, Ac-1, Ac-2, Ac-5, Ac-26 and Ac-35) of PIC were higher than the average. The Na values of 10 sample sites of A.cerana populations in Jiangxi ranged from 5.2857 to 6.3125, with an average value of 5.8247;Ho ranged from 0.3951 to 0.4602, with an average value of 0.4197;He ranged from 0.4211 to 0.4676, with an average value of 0.4437;Ne ranged from 2.7991 to 3.2596, with an average value of 2.9205;PIC ranged from 0.3909 to 0.4366, with an average value of 0.4133;I ranged from 0.9090 to 1.0106, with an average value of 0.9542;inbreeding coefficient(F_is) between 10 sample sites of A. cerana ranged from -0.036 to 0.091, F_st ranged from 0.0059 to 0.0294, and Nm ranged from 8.2534 to 42.1229.PCoA analysis, DAPC analysis and UPGMA dendrogram all showed that the population genetic differentiation of A. cerana in Jiangxi has not yet occurred.【Conclusion】The genetic diversity of A. cerana in Jiangxi is at a moderate level nationwide, and no population genetic differentiation has been found. Moreover, the role of gene exchange in the genetic differentiation process of A. cerana is greater than that of environmental selection.