凡纳滨对虾(Litopenaeus vannamei)体重、存活性状的遗传参数和基因型与环境互作效应

GENETIC PARAMETERS AND GENOTYPE BY ENVIRONMENT INTERACTION FOR BODY WEIGHT AND SURVIVAL OF PACIFIC WHITE SHRIMP LITOPENAEUS VANNAMEI

利用7个凡纳滨对虾(Litopenaeus vannamei)引进群体,通过双列杂交和巢式交配设计构建家系,建立育种基础群体,估计体重、存活性状的遗传参数和基因型与环境互作效应(genotype by environment interactions,G×E)。结果表明,凡纳滨对虾基础群体体重和存活性状的遗传力估计值范围分别在(0.19±0.09)—(0.43±0.09),(0.27±0.04)—(0.45±0.06),均属于中高遗传力水平,并且统计检验显著(P<0.05)。Z-score检验表明,体重和存活性状遗传力估计值在河北黄骅(HBHH)和青岛鳌山(QBAS)两个测试场间差异均不显著。体重和存活性状的表型和遗传相关系数分别为0.007和0.008,表现为低度线性负相关。对于体重和存活性状,HBHH和QBAS场间的遗传相关分别为0.83±0.04和0.40±0.11。体重性状的G×E效应不显著(K<0.5),但存活性状存在显著的G×E效应(K>0.5)。上述结果显示,凡纳滨对虾基础群体体重和存活性状的遗传变异丰富,多代选择可获得较大的遗传进展。

Genetic parameters and genotype by environment interaction （G^E） were obtained for body weight and sur- vival of Pacific white shrimp Litopenaeus vannamei using full-sib and half-sib families from cultured brood females col- lected from seven introduced populations. The heritability estimates for body weight and survival in the base population all ranged from moderate to high [（0.19±0.09） to （0.43±0.09）, （0.27±0.04） to （0.45±0.06）] and were significantly different from zero （P〈0.05）. The heritabilities estimated between two farm units （HBHH and QDAS） at different locations （Huanghua city and Qingdao city） were not significantly different from each other （P〉0.05） for body weight and survival using Z-score test. There was a low phenotypic and genetic correlation between body weight and survival （-0.007 and -0.008）.The genetic correlations between HBHH and QDAS farms were 0.83±0.04 for body weight, and 0.40±0.11 for survival. These correlations suggest that a low G×E effect for body weight （K〈0.5）, but a high G×E effect for survival （K〉0.5）. The results show that there is quite substantial additive genetic variance for body weight and survival in Pacific white shrimp that can be exploited through selective breeding.