关键词: 卷口鱼, 地理群体, 形态差异, 多元统计分析, Ptychidio jordani, geographical population, morphological variation, multiple statistical analysis

Abstract: According to the traditional morphological measurement of 333 Pthchidio jordani collected from upstream (Tian’e, Donglan, Dahua, Du’an and Heshan), midstream (Wuxuan, Guiping and Pingnan) and downstream (Wuzhou) on the main stream of Xijiang River in Guangxi, the morphological difference among nine geographical populations of P. jordani were explored by principal component analysis, one-way analysis of variance (One-way ANOVA), discriminant analysis and cluster analysis. Thereinto, Principal component analysis extracted a total of four principal components (PC1~PC4) which could explain 81.429% of morphological difference. The contribution rates of PC1 and PC2 were 61.830% and 7.863%,respectivel, and mainly reflected morphologic changes on the dorsal-ventral axis and tail of the fish. By making a scatter plot on the scores of PC1 and PC2, the morphological differences of most populations were easier to distinguish on the PC1 than PC2, of which Guiping, Pingnan and Wuzhou had deviated significantly from other populations. Further one-way ANOVA revealed that there were significance differences (P<0.05) in the characters of dorsal-ventral axis (D3-6 and D5-8) of these three populations with most populations. In the discriminant analysis, the comprehensive discriminant accuracy of each geographical population was 96.36% and it reached to 91.30% after cross validation. Cluster analysis found that Wuxuan population was most similar to the five populations from upstream with morphological characters, which first clustered into a single clade, then in turn clustered with far morphological distance of Wuzhou, Guiping and Pingnan populations together. In conclusion, there were significant difference about morphological of the nine wild populations of P. jordani on the main stream of Xijiang River in Guangxi. This study would provide reference for the protection management and rational utilization of the resources of P. jordani.