小黄鱼与大黄鱼及其杂交F1(小黄鱼♀×大黄鱼♂)表型差异分析

Morphological characteristics comparison of Larimichthys polyactis,L.crocea and their hybrids(L.polyactis♀×L.crocea♂)

为了阐明小黄鱼、大黄鱼及其杂交子代(小黄鱼♀×大黄鱼♂)的生长和形态差异,比较分析了3、4、6、8、11、15月龄的3种鱼的体质量,并对8月龄的3种鱼表型性状(全长、体长、头长、躯干长、尾部长、尾柄长、尾柄高、体高和体质量)进行了统计分析。结果显示,4月龄之前,小黄鱼体质量高于大黄鱼和杂交子代,之后杂交子代体质量大于小黄鱼和大黄鱼,但是从11月龄开始,大黄鱼生长速度明显加快,其体质量高于杂交子代,因此,最终杂交子代体质量介于双亲之间,表现为中亲优势。对8月龄鱼形态性状的分析可知,小黄鱼、大黄鱼及杂交子代之间的表型性状差异显著(P<0.05),其中,杂交子代的体质量和肥满度均显著高于双亲群体,表现出生长优势。对3种鱼形态性状进行聚类分析得知,杂交子代的形态性状总体上偏向于小黄鱼,表现出母本效应。聚类过程中,杂交子代首先与小黄鱼聚在一起,同样表现为母本偏向性。通过判别分析构建了3种鱼的判别函数公式,据此获得3种鱼的综合判别准确率为80.6%,其中大黄鱼判别准确率高达94.6%,而小黄鱼和杂交子代的判别准确率较为相近,分别为73.5%和74.6%,两者均低于大黄鱼,再次说明了杂交子代在形态性状方面具有母本倾向性。为小黄鱼、大黄鱼及杂交鱼的形态判别和亲缘关系鉴定以及杂交选育提供理论依据。

In order to investigate growth and morphological differences among Larimichthys polyactis,L.crocea and their hybrids(L.polyactis♀×L.crocea♂),the body weight of the three kinds of fish were compared in 3,4,6,8,11,and 15 month of age,and the phenotypic traits(total length,body length,head length,trunk length,tail length,caudal peduncle length,caudal peduncle depth,body depth,body weight,and condition factor)variations of 8 month of age L.polyactis,L.crocea and the hybrids were measured and analyzed.The results showed that the body weight of L.polyactis was significantly higher than that of L.crocea and the hybrids before 4 month.From 4 month of age,body weight of the hybrids greater than that of L.polyactis,and L.crocea,but the body weight of L.crocea higher than the hybrids at 15 month of age since the growth rate of L.crocea increased obviously from 11 month of age.Thus,at last,the body weight of the hybrids was between in those of the parents,which means the hybrid showed a mid-parent heterosis.In the results of morphological differences analysis,there were significant differences in phenotypic traits among L.polyactis,L.crocea and hybrids(P<0.05).In which,both the body weight and condition factor of the hybrids were significantly higher than the two parental groups(P<0.05).A cluster analysis revealed that the difference between hybrids and female parents is less than the difference between that and male parents,suggested the hybrids resemble female parents in morphological traits.A discriminant analysis for the morphological traits of the three groups was carried out,and three discriminant functions were established for the three groups,and resulting in a comprehensive discriminant rate of 80.6%.In which,the discriminatory accuracy of L.crocea was as high as 94.6%,which was higher than those of the L.polyactis(73.5%)and hybrids(74.6%),suggested again that the hybrids has a significant maternal effect on morphological traits.The purpose of this study is to provide theoretical basis for the morphological and phylogenetic identification and hybridization selection of L.polyactis,L.crocea and hybrids.The study would be beneficial for identifying groups,and for determining genetic relationships and breeding.