| Apis cerana cerana belongs to Hymenoptera,Apoidea,Apidae,Apis;it’s widely distributed in our country.As an important pollinating insect,it has highly ecological and economic value.The climate difference in Qinling Daba Mountain Area is obvious,which is an ideal place to study the genetic differentiation and genetic diversity of populations under heterogeneous environment and geographical barrier.At present,the basic research on genetic diversity of Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi is still very lacking,so 20 Apis cerana cerana populations were collected from 6 cities of Qinling Daba Mountain Area in Shaanxi in this study,the genetic diversity of Apis cerana cerana were analyzed with microsatellite loci and mtDNA sequence.Genetic variability within populations,population structure were estimated to provide theoretical basis for father protection and utilize of Apis cerana cerana.The main results were summarized as follows:1)A total of 175 alleles were found in 16 microsatellite loci,the average number of observed alleles was 10.938,the average value of expected heterozygosity of 16 microsatellite loci was 0.699,the average value of observed heterozygosity was 0.652,the PIC of all loci was more than 0.5,so 16 microsatellite loci showed high levels of polymorphism in Qinling Daba Mountain Area in Shaanxi in this study,which could provide more genetic information.The average number of alleles of all populations was 6.281,the average number of effective alleles was 3.852 and all the values were lower than the number of alleles,indicating that the number of alleles at 16 loci was unevenly distributed among the populations.Shannon index was 1.462,the average number of observed alleles was 10.938,the average value of expected heterozygosity of was 0.699,the average value of observed heterozygosity was 0.652,these parameters could show the genetic diversity of Apis cerana cerana in Qinling Daba mountain Area in Shaanxi.Other populations showed heterozygous deletion expect for Zhenping population,revealing the excepted heterozygosity was greater than the observed heterozygosity and Fis was greater than 0.On the whole,every populations almost showed heterozygous deletion.Only few populations had deviated Hardy-Weinberg equilibrium detection in two loci.Zhengping population experienced bottleneck effect.Fst value of all populations was less than 0.05 and the gene flow was bigger than 1,indicating that the Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi had gene exchange frenquently and no population differentiation was detected.The genetic variation relvealed by AMOVA analysis was mainly detected within populations(95%)The result of Mantel test showed that there was no significant correlation between genetic distance and geographical distance,genetic differentiation index and geographical distance among all populations.Structure cluster analysis,UPGMA and principal component analysis based on the Nei’s genetic distance showed that Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi did not differentiate,but differentiating from Guangdong population.2)The tRNAleu～COⅡ sequence of mitochondrion of Apis cerana cerana in Qin-ling Daba Mountain Area in Shaanxi is about 480 bp,which contains a noncoding region and part of COⅡ sequence.The 1～259 bp sequence of COII was used to analyze,a total of 21 variation locuses,a total of 16 haplotypes,among which,9 haplotypes were shared among some populations,and the other 7 haplotypes were unique for one population.The average haplotype diversity was 0.507,the average nucleotide difference was 0.734 and the nucleotide diversity was 0.00284.There was 13 variation locuses in non-coding region,a total of 19 haplotypes,among which,10 haplotypes were shared among some populations,and the other 9 haplotypes were unique for one population.The average haplotype diversity was 0.422,the average nucleotide difference was 0.516 and the nucleotide diversity was 0.01902.The Kimura2-parameter distance among populations ranged from 0.000～0.009 in COII region,the molecular variance analysis showed that the genetic variation within population was 85.01655%.The Kimura 2-parameter distance among populations ranged from 0.000～0.013 in non-coding region,the molecular variance analysis showed that the genetic variation within population was 93.52%.The geographical distance was not significantly related to the genetic distance.The median-joining network,phylogenetic tree,ther haplotypes of COⅡ region and non-coding regions of Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi were constructed with other Apis cerana.The haplotypes of COⅡ region were placed with other haplotypes of Apis cerana from domestic and foreign.The haplotypes of COⅡ region of Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi formed one cluster.The haplotypes of non-coding region of Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi were separated from foreign.There were some differences in the clustering results of two genetic regions,but on the whole,the Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi formed one cluster and did not produce significant genetic differentiation.At the same time,the median-joining network could also draw the same conclusion.Although the subspecies of Apis cerana had some differentiation,there was not much difference overall.3)The analysis of the microsarellite and mitochondrial DNA of the Apis cerana cerana in Qinling Daba Mountain Area in Shaanxi showed that all populations had the higher genetic diversity,had gene exchange frenquently and no population differentiati-on was detected.There was no significant correlation between genetic distance and geographical distance,genetic differentiation index and geographical distance among all populations,forming its unique genetic background.Though Apis cerana cerana in Qinling Daba Mountain Area had become a priority protection of animal resoureces,Apis cerana cerana had been fragmented distribution,so we needed to protect continually and to prevent its precious genes from being lost in a short time. |
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