Abstract:  【Aim】Scythropus yasumatsui, a major pest of Chinese jujube (Zizyphus jujuba) trees in northern China, is widely distributed in the main producing areas of jujube in provinces including Shaanxi, Shanxi, Hebei and Henan in China. This study aims to elucidate the genetic differentiation and gene exchange among S. yasumatsui populations in China. 【Methods】 Based on simple sequence repeats (SSRs) from the previously established transcriptome database, eight SSR loci were screened by PCR with fluorescence labeling and capillary electrophoresis genotyping, and the population genetic diversity was analyzed based on 308 individuals of 10 geographic populations of S. yasumatsui  from five provinces (Shanxi, Shaanxi, Ningxia, Hebei and Henan). 【Results】 All of the eight microsatellite loci had null alleles and deviated from HardyWeinberg equilibrium. Among the loci, the effective number of alleles (Ne) ranged from 2.113 to 8.016, the polymorphic information content (PIC) ranged from 0.561 to 0.908, and the expected heterozygosity (He) was between 0.476 and 0.865. The average index of genetic differentiation (Fst) among populations was 0.151, and the average gene flow (Nm) was 1.594. There was a significantly positive correlation between the genetic differentiation index and the geographic distance among different populations of S. yasumatsui (r=0.596, P=0.0035), and the phylogenetic trees based on Nei’s genetic distance and Cavalli-Sforza & Edwards genetic distance revealed that the 10 populations were all clustered into the three identical branches. 【Conclusion】 The results suggest that S. yasumatsui populations have a high level of genetic diversity, and there are a high genetic differentiation and a certain gene flow among different geographic populations. Geographic division is a critical factor which affects the genetic differentiation and gene exchange among S. yasumatsui populations.

Key words: Scythropus yasumatsui; genetic diversity, microsatellite loci, transcriptome, genetic distance, gene flow