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。
Using microalgae( SA),artificial feed( AF),Brachionus plicatilis( BP) and brine shrimp larvae( BS),four diets including SA + AF,SA + AF + BP,SA + AF + BS and SA + AF + BP + BS were formulated and used to rear Fenneropenaeus chinensis larvae. The fertilized eggs fed with SA + AF were divided into disinfection group with iodophor and untreated group,and the fertilized eggs fed with other diets were all disinfected with iodophor. The survival rates,body weight and WSSV load of post larvae at each stage were compared. The results showed that there was no significant difference in the survival rate of prawns at the N-Z stage by feeding with different diets( P > 0. 05),but the survival rate of prawns fed with BP was higher than others( P < 0. 01) at the Z-P stage. The body weight of post larvae( P10) fed with SA + AF + BP was less than that fed with SA + AF + BP + BS( P <0. 01). The WSSV load of prawns( 10. 52 ±3. 3 copies/ng DNA) fed with SA + AF were significantly lower than that of other treatments( P < 0. 05) at the P10 stage. During the P11- P60 stage,four kinds of diets,including Ruditapes philippinarum foot muscle( CF) + artificial feed( AF),R. philippinarum foot muscle radiated by60 Co γ-ray( RCF) + artificial feed( AF),potassium permanganate-disinfected R. philippinarum foot muscle( DCF) + artificial feed( AF) and artificial feed( AF),were used to feed prawns. The prawns fed with CF + AF gained the greatest increase of body weight and body length,but had no significant difference with that fed with AF( P > 0. 05); prawns fed with CF + AF and AF had significant difference with the other two groups( P < 0. 05). The survival rates of prawns fed with four different diets had no significant difference with each other( P > 0. 05). WSSV artificial infection test showed that the accumulated mortality of prawns fed with four diets were higher than 90%,and the difference was not significant( P > 0. 05).
