Molecular Ecology Of Alectories Chukar In China

Chukar partridges(Alectoris chukar)is an indicative species of arid and semiarid environments in northern China.It.has numerous subspecies with broad distribution.These subspecies might have different evolutionary history and phylogeographical structure that were heavily affected by Pleistocene glaciations. We used polymerase chain reaction(PCR)and direct sequencing methods to infer their molecular ecology based on mitochondrial DNA(mtDNA)Cytb data.The aims are:(1)to reconstruct their phylogeographical relationships within the background of Pleistocene climate.(2)to infer the effects of environmental factors on population genetic diversity of the two partridges.(3)to design sampling strategy (4)to discuss the conservation of the two partridges as viewed from genetics.This study analyzed 238 Chukar partridges including six subspecies (A.c.pubescens,A.c.potanini,A.c.pallida,A.c.falki,A.c.drungaria, A.c.pallescens).The Codon Bias Index(CBI)showed that Cytb gene had compositional bias within chukar partridges.28 variable sites defined 26 haplotypes,all populations shared haplotype C1,which is of high frequency of 58.28%.Most of pairwise differences within 6 subpopulations were significant.Calibrated rates of molecular evolution suggested that two subspecies groups began to diverged about 0.21 million years ago,mainly affected by the Pleistocene forth frigid.During 0.15-0.24 Ma,the A.c.pallescenes began to diverged with others at and formed different subspecies 0.207-0.333,so the subspeciation of it was mainly affected by Pleistocene third frigid.The A.c.potanini and A.c.pubescens independently evolved about 0.053 Ma ago due to the effect of Pleistocene forth frigid and debries flow.The phylogeographic structure of the six subpopulations belonged to "Phylogenetic continuity,spatial separation" geographic pattern,same went the six populations of A.c.potanini,resulting from the synergistic affection of glaciers, debris flow the middle and latter of the Pleistocene.Genetic diversity of A.c.potanini decreased with increasing temperature and rainfall.However,it increased with average rate of annual sunshine.Both correlations of neucleotide diversity and average annual sunshine time as well as rainfall were significant.So,average annual sunshine time and rainfall were two main factors for genetic diversity.These two factors were also most important for genetic differrenciations within populations as well as neucleotide composition. Moreover,altitude also effected the neucleotide composition.Among nine ecology factors in this study,average annual sunshine time was the most impotant one for genetic stucture of of A.c.potanini.Genetic diversity showed negative correlation with variation coefficients of temperature and rainfall,so did genetic differrenciations and sequence differences within populations Namely,the more stable the climate,the higher the genetic diversity as well as genetic differrenciations and sequence differences within populations observed.Sampling geographic scope might effected the different results of correlation of ecology and genetic structure in Alectoris.genetic diversities of populations from spacial regions with considerable ecology differences and relatively lower rainfall tended to show negative correlation with average annual temperature and average annual rainfall.When sample size reached fifteen in SL population,both haplotype diversity and neucleotide diversity tended to keep stable,and before fifteen,genetic diversity fluctuated sharply and with no rule.So we infer the reasonable sample size for a A.chukar population would be 15.A.c.pallescens population as well as TS,BS,HL,SL populations were all highly isolated,they were met the criteria for 5 different distinct evolutionary significant units(ESU).