氨氮和亚硝基氮共同胁迫对凡纳滨对虾感染WSSV的影响  

Effects of WSSV on cultured Litopenaeus vannamei under both ammonia and nitrite stress

作　　者：方金龙[1,2] 王元[1] 李新苍[1] 周俊芳[1] 陈甜甜[1,2] 房文红[1] 

机构地区：[1]中国水产科学研究院东海水产研究所,农业部东海与远洋渔业资源开发利用重点实验室,上海200090 [2]上海海洋大学水产与生命学院,上海201306

出　　处：《海洋渔业》2017年第1期85-91,共7页Marine Fisheries

基　　金：上海市虾类产业技术体系建设项目[沪农科产字(2014)第5号];上海市科技兴农重点攻关项目(沪农科攻字(2013)第6-4号)

摘　　要：为了评价养殖水环境中氨氮和亚硝基氮对凡纳滨对虾(Litopenaeus vannamei)的危害性,开展了氨氮和亚硝基氮共同胁迫对凡纳滨对虾感染WSSV后的死亡率、WSSV在患病对虾体内增殖速率和对虾主要免疫相关酶活性影响的研究。实验设置氨氮(NH+4)和亚硝基氮(NO-2)的共同胁迫浓度均为20 mg·L-1,分别注射10-4和10-5稀释度的WSSV提取液。结果显示,胁迫下感染10-4WSSV的凡纳滨对虾144 h死亡率达到100%,显著高于无胁迫组(76.67%),相同实验条件下高浓度病毒感染组死亡率高于低浓度组。对虾鳃组织WSSV荧光定量PCR检测结果显示,氨氮和亚硝基氮共同胁迫下凡纳滨对虾体内WSSV的增殖加快,感染48 h后胁迫组病毒量是无胁迫组的1.6倍,72 h时病毒量达到无胁迫组的2.0~3.7倍。此外,免疫相关酶活性结果显示,氨氮和亚硝基氮浓度突变会促使对虾血清中酚氧化酶(PO)、酸性磷酸酶(ACP)、碱性磷酸酶(AKP)活性先短暂升高然后降低。由此可见,氨氮和亚硝基氮共同胁迫会加快WSSV在患病凡纳滨对虾体内的增殖,导致更高死亡率,这可能是因为胁迫造成了对虾免疫相关酶活性的降低和抗病原感染能力下降所致。In order to evaluate the harmfulness of ammonia and nitrite on white pacific shrimp, Litopenaeus vannamei, this study was conducted to determine the combined effects of ammonia and nitrite on the mortality of white pacific shrimp infected with WSSV, WSSV proliferation in diseased shrimp and the activity of immunity-related enzymes in serum. The experiment consisted of treatments infected with PBS, WSSV extract of 10^-5 and 10^-4 dilution under the joint stress of 20 mg·L^-1 ammonia（ NH4＋ ） and 20 mg·L^-1 nitrite （ NO2 - ） , and there were relative groups without stress as control. The result showed that the mortality of the group with stress -10-4 WSSV reached 100% at 144h, significantly higher than the control group of stress- free-WSSV10-4with 76.67% mortality. Treatments with higher concentration of WSSV infection had higher mortality than that with lower concentration of WSSV infection under the same condition. Meanwhile, the amount of WSSV determined by Real-time Relative PCR showed that the stress of ammonia and nitrite accelerated WSSV proliferation in shrimp gills. The WSSV quantity of stress group was 1.6 times that of stress-free group at 48h while it reached 2.0 - 3.7 times at 72h. In addition, immunity-related enzymes activity experiment showed that the activity of phenoloxidase （PO）, acid phosphatase （ACP） and alkaline phosphatase（AKP） in shrimp serum elevated firstly and then declined with time prolonged under joint stress of ammonia and nitrite. This study indicates that synergy of ammonia and nitrite accelerates WSSV proliferation in WSSV-infected L. vaunamei and causes higher mortality, because stress environment lowers the activity of immunity-related enzymes and the ability of anti-infection of shrimp.

关 键 词：凡纳滨对虾 白斑综合征病毒 氨氮 亚硝基氮 胁迫 

分 类 号：S941[农业科学—水产养殖]