Genetic Diversity Of Five Isaria Species In Different Forest Ecosystems

Isaria spp. is an important entomopathogenic fungus, with wide host range and greateasiness for massproduction, and has been developed into fungal insecticide used mostwidely.Genetic heterogeneity of Isaria farinosa, Isaria tenuipes, Isaria cateniannulata, Isariacateniobliqua and Isaria fumosorosea, ten isolates each, was studied by use of ISSR. Theresults showed that all of them were heterogenic.The analysis by ISSR on genetic heterogeneity of I. farinose, six populations, tenisolates each, from different localities of Anhui Province, eastern China, showed that98.48%polymorphic loci was amplified with ten polymorphic primers, butpopulation-wised polymorphism varied very differently within59.57-93.18%. A Nei’sgenetic heterogenesis analysis resulted in interpopulational genetic differentiation index(Gst) at0.3365and gene flow (Nm) at0.4931; the interpopulational genetic differentiationwas lower than that intrapopulational genetic differentiation, suggesting that the geneticvariation of I. farinosa came mainly from interior of populations. A UPGMA clusteringbased on genetic similarities between isolates revealed that Xishan population wasmonophylectic while the other five were polyphylectic, with Yaoluoping population themost heterogenic and Langyashan Population the least heterogenic. The geographicdistance of the populations was not associated with the genetic distance. The sixpopulations clustered into three groups according to a UPGMA clustering based on geneticdistance between populations. The clustering results accorded with geographicenvironment and suggested the effect of environmental heterogeneity on the populationheterogeneity.The analysis by ISSR on genetic heterogeneity of I. tenuipes, five differentpopulations showed that96.15%polymorphic loci was amplified with8polymorphicprimers, but population-wised polymorphism varied very differently within61.70-94.59%.A Nei’s genetic heterogenesis analysis resulted in interpopulational genetic differentiationindex (Gst) at0.3690and gene flow (Nm) at0.4275; the interpopulational geneticdifferentiation was lower than that intrapopulational genetic differentiation, suggesting thatthe genetic variation of I. tenuipes came mainly from interior of populations. Thegeographic distance of the populations was associated with the genetic distance. The fivepopulations clustered into two groups according to a UPGMA clustering based on geneticdistance between populations. The clustering results accorded with geographicenvironment and suggested the effect of environmental heterogeneity on the population heterogeneity.The analysis by ISSR on genetic heterogeneity of I. cateniannulata, five differentpopulations showed that91.80%polymorphic loci was amplified with8polymorphicprimers, and population-wised polymorphism varied within77.97-85.96%. A Nei’s geneticheterogenesis analysis resulted in interpopulational genetic differentiation index (Gst) at0.1631and gene flow (Nm) at1.2830; the interpopulational genetic differentiation waslower than that intrapopulational genetic differentiation, suggesting that the geneticvariation of I. cateniannulata came mainly from interior of populations. The fivepopulations clustered into two groups according to a UPGMA clustering based on geneticdistance between populations. The clustering results accorded with geographicenvironment and suggested the effect of environmental heterogeneity on the populationheterogeneity. The geographic distance of the populations was not associated with thegenetic distance.The analysis by ISSR on genetic heterogeneity of I. cateniobliqua, five differentpopulations showed that97.92%polymorphic loci was amplified with8polymorphicprimers, but population-wised polymorphism varied very differently within45.45-89.13%.A Nei’s genetic heterogenesis analysis resulted in interpopulational genetic differentiationindex (Gst) at0.3507and gene flow (Nm) at0.4630; the interpopulational geneticdifferentiation was lower than that intrapopulational genetic differentiation, suggesting thatthe genetic variation of I. cateniobliqua came mainly from interior of populations. The fivepopulations clustered into two groups according to a UPGMA clustering based on geneticdistance between populations. The clustering results accorded with geographicenvironment and suggested the effect of environmental heterogeneity on the populationheterogeneity. The geographic distance of the populations was not associated with thegenetic distance.The analysis by ISSR on genetic heterogeneity of I. fumosorosea, five differentpopulations showed that97.22%polymorphic loci was amplified with6polymorphicprimers, and population-wised polymorphism varied within83.33-97.22%. A Nei’s geneticheterogenesis analysis resulted in interpopulational genetic differentiation index (Gst) at0.1327and gene flow (Nm) at1.6341; the interpopulational genetic differentiation waslower than that intrapopulational genetic differentiation, suggesting that the geneticvariation of I. fumosorosea came mainly from interior of populations. The five populationsclustered into three groups according to a UPGMA clustering based on genetic distancebetween populations. The clustering results accorded with geographic environment and suggested the effect of environmental heterogeneity on the population heterogeneity. Thegeographic distance of the populations was not associated with the genetic distance.