Population Genetics Of Apis Cerana Cerana In Northwest China

Population genetic diversity and genetic structure as well as genetic differentiation of Apis cerana cerana from north-western China were investigated through 11 microsatellites and mitochondrial tRNAlue-COâ…¡ sequences. Samples collected from 8 localities in Loess Plateau and its adjacent mountain regions were to explore the mechanism of population subdivision.The results showed that the genetic diversity of all samples was rich and genetic structure differences between populations were significant. The population differentiation between populations dwelled in varied ecological conditions could be resulted from fragmented inhabitants.（1） Population genetic diversity and genetic structure from microsatellitesFor all samples 122 alleles were detected in 11 microsatellite loci with an average of 11 alleles per locus. All the loci but AT 101 and A107 showed no deviation from Hardy-Weinberg Equilibrium. Samples both from adjacent Mountain LiuPan and Mountain QinLing exhibited much more divergent than that from central GanSu（ChG） or northern ShanXi（JB and ZZ）, with 7.6～8.0 allels or 6.3～6.9 alleles per locus on average.Genetic structure for all loci showed significantly differentiation between population pairs. Nearly all the samples shared high proportion of alleles at 5 loci（Ac₂、Ac₂6、Ac₅、A313、AT101）, on the contrary they shared different proportion of alleles at some loci（Ac₁、Ac₂6、Ac₂7、Ac₃、Ac₃5、AT101）.（2） Population genetic diversity and genetic structure from mtDNA markersFifteen mitochondrial DNA haplotypes were detected, of which 8 haplotypes were novel. Thirteen site mutation were identified, of which composed 10 transitons,1 transversions and 2 Adenine inserts.HAP00 was the dominant haplotype in all samples but GuoMiao （GM） and JingBian （JB）. The number of mitochondrial haplotypes in A.cerana from sample JB, sample JY, sample TSh was much more than that from other localities.（3） Population differentiation and isolation mechanismSignificant genetic differentiation was observed between population JB and population ZZ. Significant genetic differentiation was also observed between population GM and population JY, population LD, similarly population DX is divergent from population TSH or MZ. The genetic differentiation may be probably due to restricted gene flow between populations from fragmented inhabitants with rare vegetative cover and semi-desert area and populations from mountains. The isolated population JB, population ZZ, and population DX having low gene flow with adjacent populations was collaborated by low genetic variation. Population MZ without divergent mtDNA variation was probably due to the consequence of artificially selective breeding.This study is part of honeybee population genetics, which will contribute a lot to evolutionary ecology and conservational genetics for honeybee. To better understand A. cerana populations distributed in fragmented inhabitants and marginal area across the northwestern China will contribute to targeted breeding and conserving the locally adapted germplasm.