中华绒螯蟹2龄早熟、晚熟选育群体和非选育群体蟹种免疫性能的比较

摘要

免疫性能是评价中华绒螯蟹(Eriocheir sinensis,以下简称河蟹)蟹种质量的重要指标,采用攻毒实验和非特异免疫指标测定方法,以常规养殖未经遗传选育的养殖群体蟹种为对照组,评价了河蟹2龄早熟、晚熟选育群体第2代(G2)扣蟹的攻毒成活率和非特异性免疫指标.结果显示:(1)嗜水气单胞菌攻毒注射后,整体上未选育组扣蟹的死亡率略高于两选育群体,但是雌雄个体间具有一定的性别差异,2龄晚熟群体雄蟹和2龄早熟群体雌蟹攻毒后死亡率分别最低;(2)就肝胰腺中非特异性免疫指标而言,无论雌蟹还是雄蟹,2龄早熟群体肝胰腺中的碱性磷酸酶(ALP)活性显著高于对照组(P＜0.05),酸性磷酸酶(ACP)活性显著高于2龄晚熟组(P＜0.05);此外,两个选育组雄体肝胰腺中的总抗氧化能力(T-AOC)和过氧化物酶(POD)活性均显著高于对照组,2龄早熟G2雌体肝胰腺中的丙二醛(MDA)和谷胱甘肽过氧化物酶(GSH-Px)均显著高于其它两组雌体;(3)就血清中非特异免疫指标而言,无论雌蟹还是雄蟹,2龄早熟G2扣蟹血清中的ACP活性均显著高于对照组,2龄晚熟G2扣蟹血清中的谷胱甘肽还原酶(GR)活性均显著低于其它两组扣蟹,此外,2龄早熟G2雌蟹血清中的γ-谷氨酰转移酶(y-GT)和T-AOC活性均显著高于2龄晚熟G2.综上,两个选育群体子二代扣蟹具有较强免疫性能及抗病力,其中2龄早熟群体扣蟹的免疫性能和抗氧化能力略强于2龄晚熟选育群体.%The mature or nearly mature Chinese mitten crabs(Eriocheir sinensis) generall have higher edible yield and nutritional value than the unmature crabs,and the second instar E.sinensis ordinarly become mature or nearly mature from late October to end of December.In this period,the mature individuals of E.sinensis are concentrated to flood the market.It takes many problems like low price that need to solute.So the extension of maturing time of second instar adult E.sinensis is one of the important factors for the sustainable development of the farming industry of this crab.Previous studies have shown that selective breeding is the effective method to change the mature time for animals.Since 2011,the second instar E.sinensis of earlymaturing(ENN) and late-maturing(LM) have been established and reproduced to the third generation,but litde is known about the effects of selective breeding on the quality of juvenile E.sinensis.The immune performance is an important criteria for the evaluation of crabseed quality.Therefore,this study aimed to evaluate the survival performance during the pathogen challenge test and determine the immune indices of juvenile crabs of EM,LM and non-selective populations (as the control).The results showed that:(1) The cumulative mortality rate of the control was lower than EM and LM for both males and females during the pathogen challenge test,but there were slight differences between males and females.While the lowest mortality was found in the males of LM and females of EM,respectively.(2) In terms of the non-specific immune indicies of the hepatopancreas,EM had the higher activity of ALP and it had higher activity of ACP than LM for both males and females (P ＜ 0.05).In addition,the male EM and LM had the significantly higher T-AOC and POD than the control,and the MDA and GSH-Px of female EM were significantly higher than those of the females from the other two populations(P ＜0.05);(3) In terms of the non-specific immune indicies in hemolymph,for whether males or females,EM had higher ACP activity than the control while LM had the lowest GR activity among three populations.Furthermore,female EM had significantly higher activity of γ-GT and T-AOC than female LM (P ＜ 0.05).In conclusion,the crabseeds from early-maturing (EM)and late-maturing (LM) strains have the better disease resistance and immunity than non-selective populations,and the EM has the slightly better performance on indices of antioxidation and immunity than the LM.