Phylogeography Of Patelloida Pygmaea Along China Sea Coast

The phenotypic diversity,genetic diversity and genetic differentiation of marine organisms are the result of interactions between historical glaciation,natural barrier and environmental climate factors on different spatial scales.At present,it has revealed that marine genetic research and systematic geography research has become a research hotspot in the global marine hot area.The research on genetic structure and genetic diversity of species is developing increasingly commonplace,such as the northeast Pacific and the Atlantic Mediterranean region.This study is based on the above background,the coastal sea Chinese eurytopic gastropods Patelloida pygmaea as the research object,the use of molecular ecology,molecular phylogeography and population genetics analysis,combined with historical events,the environmental factors and geographic information.The mitochondrial DNA COI(the first subunit of cytochrome coxidase,COI)and nuclear DNA ITS-1(the internal transcribed spacer region 1,ITS-1)as molecular markers,revealing China P.pygmaea the population ecology and phylogeographic pattern and its formation mechanism,to investigate the population genetic structure of different regions of the continuous and interrupted structure of different geographic populations of the evolution of the consistency of comparison,combined with historical events,the environment and ecology the factors jointly carry out Chinese coast phylogeography of the limpet.A total of 10 absolute morphology measurements were selected and converted into relative values(relative value = absolute value / dry weight)of 137 P.pygmaea hat individuals.The results showed that the variation of relative morphological measure was more stable and the variation of various morphological measurements was consistent.ANOVA analysis of all morphological measurements F values are greater than 1 and P values are significant,indicating that the variation of the selected morphological measure contributes greatly to the total morphological variation;It is rotated by the maximum variance method,and the contribution degree of the morphological variation to the total morphological variation is determined by the variance accumulation degree,and the selected morphological variation principal components are L/DM(92.209%)and W/DM(5.726%).H/DM(1.604%);Cluster analysis found that it was mainly divided into three branches: BYSC,ECSC and SCSC.Molecular markers mt DNA COI(601 bp)C: 15.30%,T: 31.80%,A: 30.94%,G: 21.96%,found a total of 217 polymorphic loci,transformation 139,transversion 110,and define 30 haplotypes(21.89% of the total sample),total population haplotype diversity 0.971 ± 0.005,nucleotide diversity 0.3727 ± 0.1785.nr DNA ITS-1(475 bp)C: 29.34%,T: 26.72%,A: 21.86%,G: 22.08%.237 polymorphic loci were found,transformation 122 and transversion 108.54 haplotypes were defined(39.42% of the total number of samples).The most haplotypes were ST and MM(8 haplotypes).The total haplotype diversity was 0.971 ± 0.005,and the nucleotide diversity was 0.3727 ± 0.1785.A significant negative correlation was found between the principal components of morphological variation L/DM,W/DM,H/DM and the average annual variation coefficient of precipitation(P=0.006 ~0.024),and COI gene h,?,k,D,S and AAT and AAVR showed significant positive correlation.R has significant positive correlation(P=0.004~0.032)and there is a significant positive correlation between S and AAPR(P=0.062);h,?,k,have a significant negative correlation with VAAT(P=0.021~0.045)and D has a negative correlation(P=0.065).The h,?,k of the ITS-1 gene had a significant positive correlation with VAAP(P=0.002~0.037).k had a significant negative correlation with VCSS and VCSP(P=0.019~0.025),and the morphological and genetic indices were basically consistent with the environmental correlation.the main environmental factors that affect the morphological variation and genetic diversity of P.pygmaea in the China Sea.Under the environment of low latitude,high temperature,high precipitation,high water pressure,low sunshine and stable climate,the genetic diversity of P.pygmaea is higher and the precipitation is more stable.P.pygmaea greater morphological variation.The results of phylogeography research revealed that three distinct phylogeographic clades,the South China Sea(SCSC),the Bohai and Yellow Sea(BYSC)and the East China Sea(ECSC).The results of AMOVA showed significant genetic differentiation(P<0.001)among the four clades.The vicariance of the three lineages was created by the glacial sealevel dropping,the Changjiang Estuary and sea surface temperature gradient.Based on the ITS-1 gene,the BYSC was split to two subclades,north and south clades.We speculate that the Shandong Peninsula was possible another barrier limiting gene flow in the BYSC.Ocean currents played more roles within the three clades.Demographic population expansion was strongly confirmed by the non-significant mismatch distribution analysis.The expansion of BYSC,ECSC and SCSC has been found.By the expansion time,it is found that the historical expansion of Patelloida pygmaea occurs mainly in the late Pleistocene interglacial interglacial period(SCSC:0.108~0.127 Mya,ECSC:0.082~0.166 Mya,BYSC:0.033~0.103 Mya).