Morphological variability in original parents and their reciprocal hybrids F_1 of fresh water mussel Hyriopsis cumingii from three geographical populations in China

Three multivariation analysis methods(cluster analysis,principal component analysis and discriminant analysis) were used to investigate the morphological variations among three self-bred(DD,PP and TT) and six corresponding hybrids(DP,PD,PT,TP,TD and DT) in fresh water mussel Hyriopsis cumingii from three geographical populations of Dongtinghu Lake(DD),Poyanghu Lake(PP) and Taihu Lake(TT) based on ten morphological indexes.The cluster analysis indicated that there were most similar morphological characters between the stocks of DP and PD,and between DD and PP while TT had quite different morphological character from PT and DP.In the principal component analysis,three principal components were constructed,with the contributory ratio of the Factor 1,Factor 2 and Factor 3 of 21.13%,15.33%,and 17.59%,respectively and the cumulative contributory ratio of 54.05%.In Factor 1,FG and FB contributory ratio was 77.88% and 73.46%,Factor 2,OB and OD contributory ratio was 85.38% and 88.06% and OH and OC contributory ratio was 70.32% and 78.14% in Factor 3.The discriminant analysis revealed that there were significant differences among the 9 stocks(P 0.01).According to crossing group,the 9 stocks were divided into 3 groups(A,B and C) to construct discriminant functions.The identification accuracy was 56.41%-90.24%(P1) and 61.22%-97.30%(P2),and the total identification accuracy was 68.75%-79.78%.Therefore,the discriminant functions were somewhat effective distinguishing the stocks among these hybridization groups.