氨氮胁迫下白斑综合征病毒对凡纳滨对虾的致病性  

Study on pathogenicity of WSSV to Pacific white shrimp(Litopenaeus vannamei) under ammonia stress

作　　者：方金龙[1,2] 王元[1] 房文红[1] 李新苍[1] 陈甜甜[1,2] 周俊芳[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：《南方水产科学》2017年第4期52-58,共7页South China Fisheries Science

基　　金：上海市科技兴农重点攻关项目[沪农科攻字(2013)第6-4号];公益性行业(农业)科研专项经费项目(201103034)

摘　　要：为了评价养殖水环境中氨氮(NH_4-N)对凡纳滨对虾(Litopenaeus vannamei)的危害性,开展了NH_4-N胁迫对凡纳滨对虾感染白斑综合征病毒(WSSV)后的死亡率、WSSV增殖速率和对虾主要免疫相关酶活性影响的实验。在NH_4-N胁迫质量浓度为15.6 mg·L-1,分别注射2×105和2×106个WSSV粒子,结果显示,NH_4-N胁迫下注射2×105个WSSV粒子的凡纳滨对虾第144小时死亡率达到53.3%,显著高于无胁迫组(40.0%)。对虾鳃组织WSSV荧光定量PCR检测结果显示,NH_4-N胁迫下凡纳滨对虾鳃组织内WSSV的增殖加快。此外,免疫相关酶活性结果显示,NH_4-N浓度突变会促使对虾血清中酚氧化酶(PO)、酸性磷酸酶(ACP)和碱性磷酸酶(AKP)活性短暂升高后持续降低。由此可见,NH_4-N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降低和抗病原感染能力下降。To evaluate the harmfulness of ammonia on Pacific white shrimp （Litopenaeus vannamei） , we investigated the effects of ammonia （NH4-N） on mortality of the shrimps infected with WSSV （white spot syndrome virus）, WSSV proliferation and activity of immune-related enzymes in serum. The shrimps were infected intramuscularly with 2× 10^5 and 2×10^6 viral particles under the stress of 15.6 mg·L^-1 NH4-N. The results show that the shrimps with 2 ×10^5 WSSV got mortality of 53.3% at 144^th hour, which was significantly higher than that of the control group （stress-free）. Meanwhile, the real-time relative PCR shows that ammonia stress accelerated WSSV proliferation in shrimp gills. In addition, it is showed that, under ammonia stress, the activities of immunity-related enzymes such as phenoloxidase （PO）, acid phosphatase （ACP） and alkaline phosphatase （AKP） in shrimp serum continued to decrease after a brief rise. The results indicate that ammonia stress accelerates WSSV proliferation in shrimps and causes higher mortality, which is related to the decrease of activities of immune-related enzymes under ammonia stress.

关 键 词：凡纳滨对虾 白斑综合征病毒(WSSV) 氨氮胁迫 致病性 

分 类 号：S945[农业科学—水产养殖]