赤眼鳟(♀)与鳙(♂)杂交子代生物学特性

Biological characteristics of F_1 hybrid generations from Squaliobar-bus curriculus(♀) × Aristichthys nobilis(♂)

对赤眼鳟(Squaliobarbus curriculus)(♀)和鳙(Aristichthys nobilis)(♂)的杂交子一代(杂交F1)与其父母本F1一、二龄鱼的生长性能进行比较,分析了杂交F1的形态、染色体组型、倍性和红细胞大小。养殖环境分别为网箱和池塘。结果表明:该杂交组合双亲的配合力很高,连续两年试验受精率平均为59.65%,孵化率为84.93%,畸形率为4.09%,两年间分别获得鱼苗1.3万和7万尾。通过生长对照试验,杂交F1一龄鱼网箱试验生长速率比母本慢25.32%,池塘试验比母本快41.80%,二龄鱼池塘试验生长速率比父母本都慢。测定了26项形态学性状,有23项偏向母本,3项偏向父本。染色体计数和红细胞长径测定,杂交F1有二倍体和三倍体两种类型,分别是2n=48,16m+28sm+4t,NF=92和3n=72,36m+30sm+6t,NF=138。测定了88尾杂交F1红细胞长径,其中二倍体71尾,占80.68%;三倍体17尾,占19.32%。本研究旨在探讨鱼类远缘杂交的可能性和培育成养殖新品种的应用前景,并为鱼类远缘杂交理论提供基础资料。

Squaliobarbus curriculus（♀） x Aristichthys nobilis（♂） F1 is a hybrid between subfamilies. This paper compares the growth performance of the F1 with that of the offspring of both parent species, at the juvenile stage and 2-year stage, in cages and in ponds. The morphological features, karyotype, ploidy and size of erythrocytes of the F1 were also analyzed. The combining ability of the hybrid parents was very high and, over 2 years, the aver- age fertilization rate was 59.65%, the average hatching rate of their offspring was 84.93%, and the malformation rate was 4.09%. A total of 13 000 fry was obtained in the first year and 70 000 fry were obtained in the second year The growth rate of the 1-year hybrid F1 in cages was 25.32% lower than that of its female parent, but was 41.8% higher in ponds. However, the growth rate of the 2-year hybrid F1 in ponds was lower than that of its parents. Twenty six morphological features were measured, 23 of which resembled the female parent and three of which tended towards the male parent. Chromosome counts and measurements of the major diameter of erythroeytes, indicated that the F1 individuals were of two types, diploid and triploid （diploid： 2n=48, 16m＋28sm＋4t, NF=92; triploid： 3n=72, 36m＋30sm＋6t, NF=138）. From erythrocyte measurements on 88 fish, 80.68% （71） of the Fs were diploid and 19.32% （17） were triploid. The presence of both diploids and triploids in hybrid groups has rarely been reported, previously. This research aimed to provide a theoretical basis for the theory and practice of distant hy- bridization of fish.