控制环境养殖下近交对中国对虾早期体重和抗WSSV性状的影响(英文)

Effects of inbreeding on growth and WSSV resistance of the juvenile Chinese shrimp,Fenneropenaeus chinensis

过量的捕捞和不合理的人工育种措施,使中国对虾野生和养殖群体的遗传多样性均遭到不同程度的降低。本试验在相似的环境条件下养殖了40个野生对虾产生的家系和3个兄妹交产生的家系,定量测定了平均体重(1.43-1.58)g1 460尾中国对虾早期体重和感染白斑综合征病毒(WSSV)后存活时间的近交衰退系数。结果显示,野生对虾家系组的平均体重和平均存活时间分别为(1.58±0.01)g和(100.43±0.68)h,而兄妹交家系组平均体重和平均存活时间分别是(1.43±0.04)g和(85.84±1.70)h,平均体重和平均存活时间在两组间均存在极显著差异(P<0.01)。野生对虾家系组体重和存活时间的表型相关系数为0.16±0.00,而兄妹交家系组两者间的表型相关系数为0.20±0.00,但是两组间表型相关系数差异不显著(P>0.05)。近交系数每增加10%,体重和感染WSSV后存活时间分别衰退-3.80%±0.17%和-5.81%±0.11%,与近交能够降低生长和疾病抗性的观点相一致。实验结果表明,在选择育种和种质资源保护过程中都应该保证基础群体遗传背景最大化,从而有效控制近交。

To date, few studies had investigated the effects of inbreeding on growth and disease resistance, although inbreeding depression of such traits could play an important role in the evolution and ecology in Chinese shrimp, Fenneropenaeus chinensis. Effects of inbreeding on body weight and survival time post infection WSSV of juvenile shrimp were quantified in this study. All families were reared under the similar environment conditions, and the differences of growth time between two groups were not significant. The mean body weight and mean survival time of the wild shrimp group were （1.58 ±0.01 ） g and （100.43±0.68） h, and those of the shrimp group with inbreeding coefficient 25% were （1.43 ± 0.04） g and （ 85.84 ± 1.70） h, respectively. The differences of body weight and survival time post infection WSSV between two groups were all extremely significant （P 〈0.01 ）. The difference of phenotypic correlation was not significant （P 〉 0.05 ） between body weight and WSSV resistance of the wild shrimp group, which is 0.16 ± 0.00, and the inbred shrimp group, which is 0.20 ± 0.00. In this study the estimated inbreeding depression coefficient was -3.80% ±0. 17% for body weight and -5.81% ±0. 11% for survival time post infection WSSV per 10% increase in inbreeding coefficient. Results were consistent with the viewpoint that inbreeding could reduce growth and disease resistance. Those highlight the need to maximize the genetic diversity in base population, and to control the rate of inbreeding in selective breeding programs and wild resource protection.