| Ancherythroculter nigrocauda belongs to Cypriniformesus,Cyprinidaeae,Ancherythroculterus,which is endemic to the upper reaches of the Yangtze River in China.The morphological characteristics and genetic structure etc.of A.nigrocauda wild samples that were collected from Hejiang range of the Yangtze River(HJ),Longxi River(LOR)and Laixi River(LAR)during May 2016 to November 2017,to to provide basic information for the resource protection and sustainable utilization and effective management of A.nigrocauda.The main results were as follows:1.The meristic characters in the morphological measures of LOR(n=65),LAR(n=36)and HJ(n=43),the modes of the number of branched dorsal fin rays,branched pectoral fin rays and branched pelvic fin rays of the three populations were fixed values,which were 7,13 and 8,respectively.Based on the traditional morphological data and frame measurement data,the result of discriminant analysis showed that the correct classification ratio was93.8%,55.6% and 95.3%,respectively.And the average classification ratio was 84.7%,while the six principal components with cumulative contribution rate of 63.98% were from the trunk and head of the fish.The results of ANOVA showed that there were 11 variables were significantly different between LOR and LAR,4 variables were significantly different between LAR and HJ,and 12 variables were significantly different between LOR and HJ.At the same time,the result of cluster analysis of 3 populations showed that the population LAR and HJ were pooled in one clade,LOR as one clade alone.These results indicated that there were great differences between the Longxi River population and the other two populations.2.The results of mitochondrial markers(coⅠ,cytb,nd1,nd5 and d-loop)of 89 wild samples from three populations showed that the genetic diversity of A.nigrocauda was low.The number of variation site were 14,14,5,5 and 14,respectively;and 13,8,5,6 and 10 haplotypes were detected respectively.The range of haplotype diversity(h)and nucleotide diversity(π)was 0.412～0.878 and 0.00027～0.00360,respectively.The results of genetic differentiation and phylogenetic differentiation based on the sequences of coⅠ,cytb,nd5 and d-loop indicated that there was significant differentiation among the three populations.While the Longxi River population and Hejiang population were clustered into one clade in phylogenetic tree,which the genetic relationship between LAR and the other two populations was far.3.The genetic diversity analysis of 18 microsatellite loci showed that the genetic diversity of LOR,LAR and HJ were at moderate low level.The average number of alleles was2.61,2.44 and 2.39,respectively,the average number of effective alleles was 2.14,2.07 and 2.01 respectively,the average observed heterozygfosity(Ho)was 0.7921,0.7248 and0.6727 respectively,the average expected heterozygfosity(He)was 0.5259,0.5042 and0.4875 respectively,and the average PIC was 0.29,0.31 and 0.27 respectively.The genetic similarity coefficients and genetic distance among three populations were 0.9745-0.9781 and0.0148-0.0183 respectively.The genetic similarity coefficients between HJ and LOR was the largest(0.9781)and the genetic distance was the least(0.0148),while The genetic similarity coefficients between HJ and LAR was the least(0.9745)and the genetic distance was the largest(0.0183).These results indicated that the genetic diversity of the three populations of A.nigrocauda was on the moderate low level,and close genetic relationship between LOR and HJ.Meanwhile,the NJ tree of genetic distance showed that the genetic relationship between LAR and the other two populations was far.In summary,the morphological differences between LOR and other two populations were relatively large,while the morphological differences between LAR and HJ were relatively small in the morphological study.The results of molecular markers showed that the genetic diversity of the A.nigrocauda was at a lower level.There were significant differentiation among the three populations,and the genetic relationship between LOR and the HJ was closer.These results could provide scientific basis for the conservation and utilization of wild resources of A.nigrocauda. |
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