虹鳟完全双列杂交试验生长性状遗传分析

通过来自渤海、丹麦、道氏、挪威和美国加州的5个虹鳟(Onchorynchus mykiss)养殖群体的完全双列杂交试验,分别在第249天、397天、552天和771天4个时间点观测了体重和体长变化。多重比较分析发现,20个杂交组合与对应5个自繁系之间在体重或体长性状上存在显著差异(P0.05)。采用最小二乘分析法估算了不同时间点体重和体长的一般配合力、特殊配合力、反交效应、母体效应及自繁效应值。结果显示,只有少数的遗传效应是显著存在的,而且这些遗传效应在不同性状和不同时间点的表现不尽相同。整个观测过程中,渤海群体和道氏杂交组合的体重和体长生长速度都是最快的,并且在体长上与对应的自繁系比较差异显著(P0.05)。体重性状上,道氏群体的一般配合力在249日龄和397日龄时最大,且均显著存在(P0.05);母体效应在249日龄时显著存在(P0.05),其效应值仅次于丹麦群体。体长性状上,道氏群体的母体效应在249日龄和397日龄时最大,且均显著存在(P0.05)。在所有杂交组合中,渤海和道氏杂交组合最为高效,体重性状上,整个观测过程中其特殊配合力为最大;体长性状上,其特殊配合力均为正值(0.30,0.03,0.17,2.55),在771日龄时为最大,并显著存在(P0.05)。研究表明,以道氏群体作为亲本之一可有效提高虹鳟后代生长性能,渤海和道氏群体的杂交组合效果最好,可以作为选育的基础群体。

Genetic analysis of rainbow trout growth traits based on a complete diallele crossing experiment

A complete diallele crossing experiment involving the Bohai, Denmark, Donaldson, Norway, and California strains as well as self-breeding within each strain was carried out to evaluate general combining ability, specific combining ability, and reciprocal, maternal, and line-bred effects for body length and body weight in rainbow trout at four time points. The comparative analysis showed that the 20 corresponding cross combinations and five strains from self-breeding were significantly different (<i>P</i><0.05). Only a few genetic effects were significant, but the genetic effect was not the same among the different traits and time points. The Bohai and Donaldson strain cross combination had the fastest increases in body weight and body length, and length was significantly different when compared with the self-breeding results. Combining the Donaldson strain with other strains lead to significantly higher body weights at 249 and 397 days of age. A significant maternal effect of the Denmark strain occurred at 249 days of age. The maternal effect of the Donaldson strain on the length trait was significantly the largest at 249 and 397 days of age. The cross combination of the Bohai and Donaldson strains was the most efficient among all cross combinations, particularly for the weight trait. The effects of cross combination of the Bohai and Donaldson strains on the length trait were positive (0.30, 0.03, 0.17, and 0.30) with a maximum at 771 days of age. In conclusion, the Donaldson strain showed the highest growth performance of the rainbow trout offspring. The combination of the Bohai and Donaldson strains was the best and should be used as the basis for a breeding group.