Genetic Diversity Of Synuchus Nitidus Reticulates And Its Influencing Factors In A Fragmented Landscape Of The Thousand Island Lake

Habitat fragmentation refers to large areas of continuous habitat isolated by different matrices from the original habitat,thus forming a series of spatially isolated fragmented habitat.In nature,habitat fragmentation exists widely and they are one of the most important factors affecting biodiversity.The Thousand Island Lake which formed for the construction of the reservoir is known as a natural laboratory for studying the effects of habitat fragmentation.The ground-dwelling beetles on 19 land-bridge islands and 4 mainland sites in the Thousand-Island Lake(TIL)region were collected by pitfall trap methods for 6 times every spring,summer and autumn from July 2012 to April 2014.However,the sampling size was not enough,so from July 2015 to April 2017,ground-dwelling beetles were continued to be collected in the Thousand Island Lake,and we selected Synuchus nitidus reticulates which appears in every plot for the development of SSR primers and SSR molecular markers to study the genetic diversity of Synuchus nitidus reticulates.In order to know how habitat fragmentation effected on genetic diversity of Synuchus nitidus reticulates.The main conclusions are as follows:1)A DNA genomic library was constructed by high-throughput sequencing and verified by agarose gel electrophoresis,polyacrylamide gel electrophoresis,and capillary electrophoresis.And we found eight pairs of primers for subsequent experiments were obtained from randomly selected 150 pairs of SSR primers,the ratio was 5.33%;2)For the 23 microsatellite loci,the expected Heterozygosity range between 0.049 and 0.491,value of effective alleles range between 1.052 and 1.963,and the Shannon index range between 0.118 and 0.6837;3)The value of effective number of alleles(Ne)from 1.10 to 1.63;the expected heterozygosity(He)range between 0.06-0.36;the value of observed heterozygosity(Ho)range between 0.09 and 0.25,the Shannon's information index(I)range between 0.10 and 0.54;The value of within-population inbreeding coefficient(Fis)range 0.00 and 0.66.4)The value of genetic distance(D)between 0.006 and 0.177,and the genetic identity ranged between 0.841 and 0.991.The island JSD has been genetically differentiated from other plots.5)80.25% of total variance to differences within populations.6)The area of islands is correlated with the genetic diversity of Synuchus nitidus reticulates,and the perimeter,shape,isolation are negatively correlated with the genetic diversity of Synuchus nitidus reticulates.There are all no significant correlation.It can be seen that the habitat fragmentation of the Thousand Island Lake has a certain influence on the genetic diversity of.Synuchus nitidus reticulates,and the spatial characteristics of the island have not yet had a significant impact on genetic diversity.