The Study Of The Genetic Diversity And Impact Factors Of Eulecanium Cockerell Different Populations (Hemiptera:Coccidae) In Xinjiang

In this paper, both the interspecific genetic relationships of Eulecanium Cockerell’s six species andgenetic diversity, genetic variation as well as its impact factors of different Eulecanium gigantea (Shinji)populations were investigated through the inter-simple sequence repeat (ISSR) markers method, accordingto the Nei’s genetic distance analysis which were finished by UPGMA method to perform clusteringanalysis of populations. The results were showed as follow:1. The optimized ISSR-PCR system which were applied to Eulecanium Cockerell scale insects,showed the characters of better stability and repeatability.2. The genetic diversity and relationship of six Eulecanium Cockerell scale insects was investigated by37polymorphic primers: the percentage of polymorphic sites was70.79%, Nei’s gene diversity was0.2925and Shannon information index was0.2839. The genetic diversity tendency of Eulecanium Cockerell: E.gigantea (Shinji)>E. nigrivitta Borchsenius>E. kunoensis (Kuwana)>E. douglasi (Sulc)>E. ciliatam(Douglas)>E. circumfluum Borchsenius. The Nei’s heredity distance ranged from0.3733to0.6087. TheUPGMA cluster analysis of ISSR data indicated that the six scale insects which were clusted by ISSR wasbasically similar with traditional method, scale insects were generally classified into3groups of differentspecies, the E. ciliatam (Douglas), E. circumfluum Borchsenius and E. nigrivitta Borchsenius wereclustered into one group, the E. kunoensis (Kuwana) and E. douglasi (Sulc) were clustered into anothergroup and E. gigantea (Shinji) were clustered into independent group.3. The genetic diversity and genetic structure of15E. gigantea (Shinji) populations from differentgeographic in Xinjiang was investigated via46selected polymorphic primers: the percentage ofpolymorphic sites was85.7%, Nei’s gene diversity index was0.3346and Shannon information index was0.4256. These data suggested that the genetic diversity of E. gigantea (Shinji) was quite high at specieslevel. The Nei’s heredity distance ranged from0.01to0.17among fifteen populations. Based on Nei’s Gstvalue,64.63%of genetic variance was among individuals within population, gene flow among populationswas0.9136. UPGMA cluster analysis showed that the165individuals were generally classified into fivegroups; the Yecheng-Moyu groups had a closest relationship and relatively shortest differentiation time.4. Correlation analysis showed that the genetic diversity of E. gigantea (Shinji) populations waspositively correlated with annual temperature and annual humidity, but less correlated with host andlatitude individually, and negatively correlated with elevation. Besides, the genetic distance between thepairs of the random populations was positively correlated with mean annual temperature.5. The genetic variation and relationship of E. gigantea (Shinji) populations which were parasited onZizyphus jujube, Ulmus pumila L., Sophora japonica Linn from Hami in Xinjiang was investigated by18polymorphic primers: the percentage of polymorphic sites was88.13%, Nei’s gene diversity index was0.2280and Shannon information index was0.3186. The genetic diversity tendency was: Zizyphusjujube>Sophora japonica Linn.>Ulmus pumila L. The Nei’s heredity distance ranged from0.063to0.100among three populations. Based on Nei’s Gst value,65.49%of genetic variance was among individualswithin population, gene flow among populations was0.9488. UPGMA cluster analysis showed that Ulmuspumila L. and Sophora japonica Linn had closest relationship.