盐度变化对携带白斑综合症病毒(WSSV)的凡纳滨对虾(Litopenaeus vannamei)的影响  

EFFECTS OF SALINITY CHANGES ON LATENT INFECTION OF WHITE SPOT SYNDROME VIRUS IN LITOPENAEUS VANNAMEI

作　　者：向赟[1] 王刚[1] 叶国锋 陈兆明[1] 杨世平[1,2] 王成桂 孙成波[1,2] 

机构地区：[1]广东海洋大学水产学院,湛江524025 [2]广东高校热带海产无脊椎动物养殖工程技术研究中心,湛江524025

出　　处：《海洋与湖沼》2014年第2期427-435,共9页Oceanologia Et Limnologia Sinica

基　　金：广东省海洋渔业科技推广专项;A201301D02号;广东省良种体系项目;湛财农[2012]221号

摘　　要：研究盐度渐变和突变对WSSV在凡纳滨对虾(Litopenaeus vannamei)体内增殖的影响。结果表明,盐度由起始盐度(23±1)往高盐度(32±1)和低盐度(14±1)突变在整个实验中对凡纳滨对虾的累积死亡率和对虾体内病毒增殖的影响显著(P<0.05),先感染WSSV实验,高盐度、起始盐度、低盐度累积死亡率分别为(61.1±10.7)%、(48.9±1.9)%、(63.3±12.0)%,病毒含量分别为6.0×107、3.7×106、5.3×107 copy/g;后感染WSSV实验,分别为(75.6±3.8)%、(52.2±13.4)%、(63.3±3.3)%;病毒含量分别为5.7×107、2.3×106、2.8×107 copy/g。盐度渐变实验各组至24h对虾死亡率低于18.9%,48h出现死亡高峰,72—96h存在显著差异(P<0.05),先感染WSSV实验,高盐度、起始盐度、低盐度最大死亡率分别为(75.6±5.1)%、(38.9±5.1)%、(69.3±6.9)%,病毒含量分别为7.6×107、5.3×106、2.4×106copy/g;后感染WSSV实验分别为(46.7±10)%、(45.6±18.9)%、(74.4±13.9)%;病毒含量分别为5.1×106、4.8×105、1.0×107 copy/g。因此盐度变化会影响对虾的抗病能力,可造成对虾体内WSSV快速增殖;对携带WSSV对虾,盐度变化会大大提高WSSV从潜伏感染转为急性感染的可能,盐度是引起WSSV从潜伏感染转为急性感染的关键影响因子之一。We explored the effect of gradual or sudden salinity change on proliferation of white spot syndrome virus(WSSV) in Litopenaeus vannamei. Results show that a sudden salinity change from initial(23±1) to(32±1) or at a low salinity(14±1) could affect significantly(P<0.05) the mortality of and WSSV proliferation in L. vannamei. In pre-WSSV-infection experiment, the largest cumulative mortality rates at high, initial lethal, and low salinities were 61.1%±10.7%, 48.9%±1.9%, and 63.3%±12.0%; and the virus content were 6.0×107, 3.7×106, and 5.3×107 copy/g, respectively. However, in post-WSSV-infection experiment, the maximum cumulative mortality rates were 75.6%±3.8%, 52.2%±13.4%, and 63.3%±3.3%; and the virus contents were 5.7×107, 2.3×106, and 2.8×107 copy/g, respectively. In the experiment of gradual salinity change, the mortality in each group was below 18.9% in 12h, reached mortality peak in 48h, and varied significantly in 72—96h. In the pre-WSSV-infection experiment, the largest cumulative mortality rates of high, initial-lethal, and low salinities were 75.6%±5.1%, 38.9%±5.1%, and 69.3%±6.9%; the virus content were 7.6×107, 5.3×106, and 2.4×106 copy/g, respectively. In the post-WSSV-infection, the largest cumulative mortality rates were 46.7%±10%, 45.6%±18.9%, and 74.4%±13.9%; the virus contents were 5.1×106, 4.8×105, and 1.0×107 copy/g, respectively. Therefore, salinity change could affect the disease resistance of the shrimp for causing rapid WSSV proliferation in vivo in shrimp. For those WSSV-borne shrimp, salinity changes could increase greatly the risk of latent to acute WSSV-infection. Therefore, salinity increase in both gradual and sudden ways could be a key reason for causing WSSV outbreak.

关 键 词：盐度 凡纳滨对虾 白斑综合症病毒 实时荧光定量PCR 病毒含量 

分 类 号：S945.49[农业科学—水产养殖]