牙鲆抗鳗弧菌病家系筛选及其分析

Comparative analysis of disease resistance among Japanese flounder (Paralichthys olivaceus) families

2007年以从养殖牙鲆(Paralichthys olivaceus)中筛选出的抗病选育群体、从日本引进的日本群体以及从黄海捕捞的野生群体为基础,进行各种组合方式的交配,建立了63个牙鲆家系;2008年又建立了30个家系。对2007年培育的59个家系和2008年培育的30个家系进行了鳗弧菌(Vibrio anguillarum)感染实验,结果表明,不同家系间的抗病力存在极显著的差异(P<0.01)。从2007年培育的59个家系中筛选出4个抗病家系,鳗弧菌感染后存活率达到50%以上;2008年的30个家系中5个家系抗病力较强,鳗弧菌感染后的存活率达到60%以上。2008年培育的30个家系其4月龄和6月龄的感染后存活率的相关系数为0.403(P<0.05),表明不同生长时期的感染结果具有一致性。230d的体长和体质量与对鳗弧菌的抗病力存在显著的相关关系(P<0.05),皮尔森相关系数分别为0.282和0.237。研究发现,日本群体与抗病选育群体的杂交后代抗病性能表现优异,可以通过日本群体与中国群体间的杂交进行遗传改良,达到培育出高产、抗病牙鲆新品种的目的。

Japanese flounder （Paralichthys olivaceus） is a widely cultured marine fish species in China because of its fast growth and good taste. However, diseases of the cultured fish have occurred frequently because of decreased resistance which is caused by inbreeding. Thus, to breed new flounder strain with enhanced disease resistance and growth rate is an important task in marine aquaculture. In this study, Japanese flounder for creating base population high of test fish were collected from Japanese stock （JS）, Yellow Sea wild stock （YS） and resistance stock （RS） to Vibrio anguillarum. Sixty-three halt＇- and full-sibling families of Japanese flounder were established using six cross combinations among the three stocks in 2007. Thirty families were established in 2008. Disease resistance was evaluated in fifty-nine families and thirty families through intraperitoneal injection challenge with V. anguillarum in 2007 and 2008, respectively. Results demonstrated that there was significantly difference in disease resistance among different families （P〈0.05）. Some families showed high disease resistance to V. anguillarum, while others showed lower disease resistance. Among the 30 tested families in 2008, five families （family 08-17,08-31,08-42,08-43 and 08-44 ） with high disease resistance were identified whose survival rates were over 60%. The results of ANOVA analysis showed that there were significant differences among different cross combinations and among different families in the same combination on disease resistance performance （P〈0.05）. Correlation analysis demonstrated that there was significant correlation between growth performance and disease resistance on 230 days （P〈0.05）. It was found that the hybrid between Japanese stock and high resistance stock showed higher disease resistance compared with other combinations, and Japanese stocks might play an important role in selective breeding of flounder stains with fast growth and disease resistance.