Growth performance and morphological characteristics analysis of the hybrid F₁, Megalobrama terminalis (♀)×Culter alburnus (♂)

In the present study, a hybrid F₁ of Megalobrama terminalis (♀)×Culter alburnus (♂) (MT♀×CA♂) was obtained by intergeneric crossing, based on M. terminalis, from Dongjiang River, and C. alburnus, from Dianshan Lake. Growth performance and morphological characteristics of MT♀×CA♂ were compared and analysed further, with M. terminalis (MT), C. alburnus (CA), M. amblycephala (♀)×C. alburnus (♂) F₁ (MA♀×CA♂) and M. amblycephala (MA) as controls. The results are as follows: (1) at 1-year-old stage, both MT♀×CA♂ and MA♀×CA♂ grew significantly faster than CA, suggesting a remarkable growth advantage of over-male-parent. At 2-year-old stage, MT♀×CA♂ was similar to MA♀×CA♂ in growth rate, which grew faster than their parents. At 3-year-old stage, the hybrid MT♀×CA♂ had not only marked growth advantage of over-dual-parent, but also its body weight exceeded MA♀×CA♂ value. (2) Most numeric traits of MT♀×CA♂ presented to be medium. Among countable traits, the numbers of soft ray of anal fin and other traits are within the range of its parents, the average hybrid index is calculated to be 65.00, which shows that the countable traits approach the middle values between MT and CA, while slightly incline to its male parent CA. Of measurable traits, seven traits are significantly different from its parents, the average hybrid index is calculated to be 51.61, which indicates the measurable traits are also close to the middle values. (3) The results of cluster analysis revealed that MT♀×CA♂ and MA♀×CA♂ were much closer, the same to the MT and MA, joined CA again after the two groups clustered. Three principal components with accumulative variance percentage 56.02% were summarized in principal component analysis, reflecting the morphological variations of frame, head and caudal peduncle. Discriminant accuracy was 87.1%–100.0% by established discriminant function of the populations. In summary, the hybrid F₁ of MT♀×CA♂ showed advantageous characteristics such as fast growth and excellent morphology, and it is expected to further cultivate improved varieties.