Isolation Of Polymorphic Microsatellite Loci And Population Genetic Structure Studies For Liriomyza Sativae Blanchard(Diptera:Agromyzidae)

Liriomyza sativae Blanchard (Diptera:Phytomyzidae) has a high reproductive rate, a wide range of host plants, short developmental phase and overlapping generations. As a result, L. sativae usually rapid outbreak and become an important pest of horticulture crops. Polymorphic microsatellite loci of the L. sativae were isolated by FIASCO method at first time. Then, we used these microsatellite loci to evaluate the genetic diversity and genetic structure of12geographical population in China, The main results were now summarized as follows:1. A total of15polymorphic microsatellite loci were isolated. The polymorphic information content (PIC) of these15loci were all greater than0.5, which showed a high degree of polymorphism. The alleles number of loci ranged from7to19, the observed heterozygosity (Ho) ranged from0.479-0.830, and the expected heterozygosity (He) ranged from0.668-0.914. After sequential Bonferroni correction,7loci showed significant deviations from Hardy-Weinberg equilibrium and JY60&JY67B, JY60&JY70B, JY1&JY73B were linkage disequilibrium between them.2. In order to assess interspecific amplification, cross-species amplification was tested in other four leafminers, Liriomyza trifolii, Liriomyza bryoniae, Liriomyza huidobrensis and Liriomyza chinensis.13microsatellite loci could be successfully amplified in different levels in four closely related species expect JY4and JY18B. Particularly, JY1, JY14, JY26, JY46and JY60could be successfully amplified in all four closely related species. The result showed that the15polymorphic microsatellite loci had high versatilely.3. By studying the genetic diversity of288individuals in12geographical population, We found that, the average alleles number across populations was5.4-8.7and all the expected heterozygosity were greater than0.6, which showed the12populations had higher genetic diversity.4. The genetic differentiation showed that63.6%of the populations had taken place the moderate genetic differentiation (0.05<FST<0.15), Zhejiang and Shanxi populations had the largest genetic differentiation (FST=0.1464); the FST of Guizhou and Guangdong populations was-0.0036, indicating that there is no differentiation between the two groups. The Nm were greater than1between all the populations, which indicated that the genetic drift among populations had not become a major factor in the changes of genetic structure. The results of genetic distance showed that, the genetic distance betwween Guizhou and Guangdong populations was smallest (0.0644), the genetic distance between Guangxi and Jiangsu was largest (0.6650). As a whole, the genetic distance between Guangxi and Shanghai was small, the genetic distance of these two populations and other populations were large, and the genetic distance between other populations were small. So we can infer that the genetic differentiation between L. sativae populations was a synergistical result of multiple factors, such as the transport of horticulture crops and the diversification of invasive sources.5. The bottleneck effect test showed that, several populations were significantly deviated from mutation-drift equilibrium under the IAM model, It suggested that these populations had experienced a recent population bottleneck, but the whole L. sativae population is steady or even may have a tendency to increase.