| The process of a landscape scale is called Habitat fragmentation that a larger,continuous natural habitat is divided into a small,isolated,space isolation from each other on small patches.Habitat fragmentation will result in the changes of habitat spatial structure,such as gradually reduced suitable habitat,habitat patches,distance between habitat and so on.Recently,due to the rapid development of global economy,the artificial habitat fragment has become an important reason for the declining of global biodiversity.Study of habitat fragmentation caused by human activities is becoming more and more common.And the genetic diversity of habitat fragmentation on species can better explained from the different space and different time scales,that can provide more reliable scientific basis for the protection of the species,and develop more effective protection measures.And compared with habitat islands land system,land bridge library plaques have the same species as the mainland.the significant edge of the habitat patches,isolated single matrix and the formation of the same time as the advantages of the landscape pattern is clear.Therefore,it is more ideal to study the effect of habitat fragmentation on land-bridge island.In this study,we reveal the influence of habitat fragmentation to Odorrana schmackeri through the contrast of genetic diversity and genetic structure of the dififerent habitat's Odorrana schmackeri.In addition,different analysis methods are used to analyze the history of climate change and the recent fragmentation for the influence of population dynamics.The results of the study include the following.1.We analyze the 14 population in island and 7 populaton in mainland and its genetic diversity and genetic structure by 9 microsatellite locus.The levels of genetic diversity populations from the island region(AR=5.71;NA=7.29;HE=0.70)are higher than those from the mainland(AR=4.97;NA=6.51;HE=0.68).Population of island(FST=0.051)and mainland(FST=0.087)are realized for significant genetic structure,population genetic differentiation between the islands is slightly less than mainland populations,and the inbreeding coefficient(Fis = 0.325)higher than mainland populations(Fis = 0.028).Although,the result of molecular variation analysis(AMOVA)show that Odorrana schmackeri in the islands and the mainland have genetic differentiation between populations,but the main source of genetic variation is within populations.The genetic variation among island populations(5.07%)is lower than that of mainland populations(8.72%).A population of Odorrana schmackeri is divided into five genetic clusters.The mainland populations are divided into two genetic clusters,the island populations are divided into three genetic clusters.The contemporary level of gene flow is relatively low in islands(mBay<0.014)between population and mainland between populations(mBay<0.029),the level of gene flow between island populations is slightly less than mainland rate of gene flow between populations.The test result of the Wilcoxon sign-rank in Bottleneck software:In IAM mode,there are four island populations with bottleneck effect,and the mainland populations are not found;In TPM mode,there are 7 island populations with bottleneck effect,there are 3 mainland populations with bottleneck effect;In SMM mode,there are 8 island populations with bottleneck effect,there are 3 mainland populations with bottleneck effect.The AFD detection found:only in 04 population occured the variation,because of population may experienced decline.But it is possible that the population is recovering from the influence of the founder effect.2.We analyze the gene flow of the population in island by method for analyzing genetic data based on different time scales.There is a wide range of gene flow in the historical and the contemporary in the populations of the Odorrana schmackeri.However,The historical migration rate is significantly higher than the contemporary gene flow among the island population.The results of BayesAss analysis show that the contemporary gene flow is relatively low(0.001-0.174)among the populations.The results of Migrate-n analysis showed that the historical migration rate is in the range of 4.139-115.501 among all island populations.We are also found that 07 and 14 of the population had a limited source of gene flow,and the population of 14 is the main source of gene flow in the population of 07 and 13.However,the result of the historical gene flow shows 07,13,and 14 population is widely distributed in the gene flow of population,and there is no significant difference in gene flow between populations.The net historical migration rate of 7 populations are negative,and the net historical migration rate of 7 populations are-positive.The net contemporary migration rate of the population is only negative for a population(14),and the net contemporary migration rate of other populations is positive. |
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