| The genetic diversity of three wild fishesin the Pearl River Basinwere analyzed by Morphological markers and molecular marker.The traditional measurable trait and frame structure were analyzed using morphological markers.Besides,molecular marker was mitochondrial DNA including Cyt-b gene and D-Loop sequence.134 samples of Pseudolaubuca sinensiswere collectedfrom 5 populations,278 samples of Pseudohemiculter disparwere collected from 9populations,317 samples of Hemicculter Leucicluswere collected from 10 populations.The results of 9 traditional measurable characters and 24 frame structure charactersshowed that: 1)Pseudolaubuca sinensis: single factor analysis of variance showed that there were significant differences between the Gui River and other populations in the most of traits(P<0.05);Principal component analysis(PCA)yieldeds 3(traditional)and 7(frame)principal component factors,which could explain the morphological differentiation among populations.The cluster analysis suggested that there was no significant relationship among populations.2)Pseudohemiculter dispar: single factor analysis of variance showed that there were significant differences amongthe populationsin the Eye Diameter,Interorbital Distance and Body Height(P<0.05),and there was no significant difference in Head Length(P>0.05);In contrast,Head Length was subject to minimal environmental selection pressure;Principal component analysis(PCA)yieldeds 3(traditional)and 7(frame)principal component factors,explaining the morphological differentiation among populations;cluster analysis showed thatthere were a closer relationship between Zuo River and Rong River population,Gui River populationand Bei River population.3)Hemiculter leucisculus: single factor analysis of variance showed that the population of Rong River and Bei River were significant differences to other populations in the most of traits(P<0.05);Principal component analysis(PCA)yieldeds 3(traditional)and 7(frame)principal component factors,explaining the morphological differentiation among populations;cluster analysis showed thatthere was a closer relationship between the population of Dong Riverand Li River.Results of two mitochondrial molecular markers of C yt-b gene and D-Loop sequence: 1)The genetic diversity level of Pseudolaubuca sinensis was low(Hd=0.77859/0.74391,π=0.00352/0.00297),and only Hengxian population(Hd=0.83810/0.70476,π =0.02018/0.00979)revealed a high level of genetic diversity;Genetic differentiation and genetic distance analysis showed that: There was a lo w level of genetic differentiation among geographic populations of Pseudolaubuca sinensis(Fst<0.15,N m>1),Phylogenetic analysis showed that there was no clear geographical distribution difference among geographical populations.2)The Pseudohemiculter disp ar populationdisplayed high level of genetic diversity in the Pearl River Basin(Hd=0.95438/0.96295,PI =0.07197/0.07144).Whereas,displayed special case of high haplotype diversity and low nucleotide diversity in the Dongjiang and Zuo Youjiang(Hd>0.5,π <0.005);Genetic differentiation and genetic distance analysis showed that: The population betwee n the Yu River,Rong River,Zuo River,You River populations of each other and the populations between Duliu River and Gui Riverit revealed a low levels of genetic differentiation(Fst<0.15,N m>1).The genetic relationship was close(D<0.05),and other geographical groups had a high degree of genetic differentiation(Fst>0.25,N m<1),genetic relationship was far away.The phylogenetic analysis showed that the populatio n of Q ianjiang was clustered into one branch,and the Dongjiang group was clustered into another branch.3)The Hemiculter leucisculus populations displayed high level of genetic diversity in the Pearl River(Hd=0.74666/0.94148,PI =0.02830/0.02083).Whereas,the special phenomenon of low haplotype diversity and high nucleotide diversity appeared in Lijiang River(Hd=0.30317/0.38889,π =0.01095/0.01171);Genetic differentiation and genetic distance analysis showed that: there was a high degree of genetic differentiation between the Lijiang population,Duliujiang population and other populations.The other geographical populations were still in the middle or low level of genetic differentiation.The phylogenetic analysis showed that the population of li River was clustered into one branch,and the Duliug River group was clustered into another branch.Above all,the genetic diversity of Pseudohemiculter dispar and Hemicculter Leuciclus is in good condition.But the genetic diversity of Pseudolaubuca sinensis is poor.Therefore,we should pay more attention to the Fishery resources conservation and management in Pseudolaubuca sinensis. |
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