Abstract:  Cacopsylla chinensis (Yang et Li) is one of the main pests of pear. In order to estimate the genetic variability within populations and genetic differentiation among populations of C. chinensis at the molecular level, genetic diversities of 16 geographic populations of C. chinensis in China were analyzed with 7 microsatellite loci. The results showed that the number of effective alleles and the polymorphism information content (PIC) per locus were 2.2927-10.0610 and 0.5073-0.8735, respectively. The average expected heterozygosity of all C. chinensis populations was 0.7876. The genetic distances between different populations were 0.0951-1.0139, the Nei’s expected heterozygosity 0.4771-0.7892, and the Shannon information indexes 0.8396-1.9989. The average value of inbreeding indexes (F_ST) and gene flow were 11.61% and 2.2236, respectively. The results indicated that the seven microsatellite loci are of high polymorphism, C. chinensis in China keeps a low level of population genetic differentiation and high degree of gene flow, and genetic variability mainly exists between individuals within populations. The results provides some basic information on molecular biology for the development of effective control strategies of the psyllid.

Key words: Cacopsylla chinensis, microsatellite marker, geographic population, genetic diversity, gene flow