达氏鳇、施氏鲟及其杂交种(施氏鲟♂×达氏鳇♀)形态差异与判别分析

采用形态学和多变量形态度量方法,对养殖施氏鲟(Acipenser schrenckii)、达氏鳇(Huso dauricus)及其杂交种(大杂交)(达氏鳇(♀)×施氏鲟(♂))的形态差异和判别进行了分析。结果表明:(1)养殖施氏鲟、达氏鳇及大杂交头部形态差异明显,口唇形状、吻须形状及长度、鳃盖膜形态差异显著。在7项可数性状中,大杂交胸鳍、侧骨板、腹骨板和鳃耙数偏母本性状(HI>55),臀鳍条数明显地偏父本性状(HI<55),背骨板数偏离双亲性状,背鳍条数为中间性状。可数性状的平均杂交指数为74.97,总体上偏向于母本。可数性状中鳃耙数可作为判断三者所属的指标;(2)单因子方差分析显示,大杂交与施氏鲟有5个比例性状存在显著差异(P<0.05),与达氏鳇有4个比例性状存在显著差异(P<0.05);(3)聚类分析表明,大杂交与达氏鳇在外观形态上更为近似,二者聚在一枝,然后与施氏鲟聚集;(4)主成分分析构建了4个主成分,其贡献率分别为41.429%、37.809%、7.869%和5.790%,累积贡献率为92.896%,主成分分散图表明大杂交在形态差异上独立于施氏鲟和达氏鳇;(5)采用逐步判别分析获得5个比例性状构建了区分上述三个种的判别函数,判别函数预测分类总体准确率达96.67%,其中对大杂交的判断准确率达100%。研究认为,杂交鲟在形态上较接近于其母本达氏鳇,但可以通过形态判别分析将大杂交与母本达氏鳇和父本施氏鲟进行区分判别。

Comparative discriminate analysis of morphological traits among Acipenser schrenckii, Huso dauricus and their hybrid (A.schrenckii (♂) × H.dauricus (♀))

The morphological variations and discriminant methods of Acipenser schrenckii,Huso dauricus and their hybrid(A.schrenckii(♂)× H.dauricus(♀)) were studied using traditional morphometrics and multivariant statistical analysis.The results showed significant differences among A.schrenckii,H.dauricus and their hybrid from lip shapes,snout shape,barbels shape and length,and branchiostegal membrane of head.Among seven meristic characters,the numbers of pectoral fins,side plates of bone,belly bone and Gill rakes were partial to their female parent.The number of anal rays was obviously partial to their male parent.The average hybrid index of meristic characters was calculated to be 74.97.Gill rakes can be used as preliminary indicators to determine the three species.One way analysis of variance,cluster analysis,PCA(principal component analysis),and discriminatory analysis were apply to evaluate morphological differences on three species.The result of analysis of variance showed that,five proportional morphological traits were significant ly different(P<0.05) between the hybrid and A.schrenckii;four traits were significant ly different(P<0.05) between the hybrid and H.dauricus.The result of cluster analysis showed that,morphous of hybrid was more similar to H.dauricus than A.schrenckii.In PCA(principal component analysis),four principal components were constructed by factor loadings.The contribution ratios of the first four principal components were 41.429%,37.809%,7.869% and 5.790%,the cumulative contribution ratio was 92.896%.Three discriminate function were established in discriminatory analysis,the average discriminant accuracy was 96.67%,the discriminant accuracy of hybrid was 100%.The results of our study suggests that multivariate analysis of proportional morphological traits should be a feasible way to identify and distinguish the morphological differences among the A.schrenckii,H.dauricus and hybrid of H.dauricus(♀) ×A.schrenckii(♂).