Population Genetic Structure And Effective Population Size Of The Bamboo Locust Ceracris Kiangsu Based On Microsatellite Markers

Yellow-spined bamboo locust also called Ceracris kiangsu Tsai,is known as a worst important pest of bamboo in China.The nymphs and adults of this species mainly feed on the leaves of bamboo plants,which cause new culms dying and a decrease in production of bamboo plant,and harm bamboo resources in southern China,hence hinder the development of forestry.People have mastered their biological property and various studies on the disaster prediction,prevention and trapping of C.kiangsu have been launched.But their eruption mechanisms and disaster prediction standards is not well known,especially lacking of the population structure and genetic information.So far,our group has carried out the research for C.kiangsu and successfully screened out 12 pairs of microsatellite primers and several mitochondrial primers,which still needs further research.The results of the study are as follows:1.To further investigate the genetic structure under different geographical conditions and explore the genetic diversity of different populations,10 microsatellite markers were used for 18 different geographic populations in this study.All 10 loci with varying degrees of polymorphism,which provided a powerful tool for genetic diversity,population genetic structure,gene flow,effective population size and other studies of 18 C.kiangsu populations.The number of alleles in each locus ranged from 27 to 43,and the observed heterozygosity and expected heterozygosity ranged from 0.7429 to 0.9714 and from 0.7193 to 0.9308,respectively.The results of Bonferroni correction showed that,these 10 loci significantly deviated from Hardy-Weinberg equilibrium(P<0.001),which showed significant linkage disequilibrium between 14 pairs loci.Versatility testing for primer pairs showed that seven of the 10 primer pairs could be used in the subfamily Ceracrinae for genetic analysis.Unfortunately,the application about Acrididae was confined.2.Based on 10 microsatellite loci,we evaluated the genetic diversity and genetic differentiation of 433 samples of 18 natural populations distributed in southern China.The results showed a rich genetic diversity in 343 individuals of C.kiangsu population amplified by 10 loci,the average number of alleles per locus was 34.3.The observed heterozygosity of population groups was 0.7099 ± 0.0069 and observed heterozygosity of all populations ranged from 0.5600 ± 0.2089 to 0.8543 ± 0.0966 and expected heterozygosity ranged from 0.7636 ± 0.1033 to 0.9143 ± 0.0312.Observed heterozygosity values of all populations were below expectations(HE>HO),indicating heterozygosity deficiency.Only one population(Hunan Anhua,AA)had a negative inbreeding coefficient(FIs<0)in 18 geographic populations,there were 17 inbred populations of certain phenomena(Fis>0).STRUCTURE and FCA analysis showed that there was no obvious geographic differentiation pattern in the genetic structure in C.kiangsu populations,local populations had a mixed ancestry and there have been extensive gene flow in history;AMOVA analysis showed that 92.98%genetic variation have occurred within populations;populations were significantly deviated from mutation-drift equilibrium with heterozygote deficiency under the TPM and SMM models using the program BOTTLENECK.The results suggested that the C.kiangsu population may have been suffered the recent population bottleneck.3.We used the single sample methods(Linkage Disequilibrium and Approximate Bayesian Computing)to evaluate the effective population size of C.kiangsu.ONeSAMP software showed a result that Ne value ranged from 52(TY,Hunan Taoyuan)to 614 GN(Guangning).LDNe software showed that Ne ranged from 77(TY,Taoyuan)to 813(GN,Guangning).The global evaluated of all populations showed a Ne of 211,which indicated a moderate level of Ne.Genetic bottlenecks may affect the Ne,and low Ne indicated that the population usually experienced genetic drift and low genetic diversity.The evaluation of LDNe and ONeSAMP softwares for population provided the effective population size information of C.kiangsu;effective pest control measures should be implemented.More samples and environmental factors should be taken into consideration to get more genetic information of C.kiangsu in further estimates.