牙鲆连续三代抗鳗弧菌病家系的筛选与分析

为了培育牙鲆(Paralichthys olivaceus)抗鳗弧菌(Vibrio anguillarum)病的品系或品种, 2009和2012年利用中国牙鲆抗病群体、从日本和韩国引进的牙鲆群体以及2007年和2009年从大量牙鲆家系中选留的优良家系为亲本, 通过巢式杂交、三元杂交及雌核发育等方法, 分别于2009年和2012年建成牙鲆家系43个和65个, 选取2009年的33个家系和2012年的43个家系进行鳗弧菌感染实验, 共筛选出13个抗病家系, 其中3个家系的存活率极显著高于对照组(P<0.01), 另外10个家系的存活率显著高于对照组(P<0.05), 这13个家系包含F3家系、雌核发育一代和二代家系各1个, F2家系3个, 在以上6个家系中,除了1个F2家系, 其他家系的亲本均来自于抗病家系且鳗弧菌感染存活率的变异系数都低于10%。对连续三代抗病家系进行分析, 发现在上述13个抗病家系和2007年筛选出的3个抗病家系共16个抗病家系中有13个家系来自于中国牙鲆抗病群体相关, 结果表明, 部分F1、F2、F3和雌核发育家系较好地遗传了其亲本的抗病性能, 抗病性能稳定, 为培育抗鳗弧菌病的牙鲆品系或品种奠定了基础。

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

Japanese flounder(Paralichthys olivaceus) is a widely cultured marine fish species in China and is highly valued because of its fast growth and good flavor. However, frequent occurrence of disease and subsequent losses limit profitability and aquaculture development. Breeding a new flounder strain with enhanced disease resistance is an important task in marine fish aquaculture. In the present study, new Japanese flounder families were established based on Japanese stock (JS), Korean stock (KS), and stock with high resistance to Vibrio anguillarum (RS) by nested hybrid, cross, and gynogenesis. Forty-three and sixty-five Japanese flounder families were established in 2009 and 2012, respectively. Disease resistance was investigated using 33 families in 2009 and 43 in 2012 through intraperitoneal injection challenged with V. anguillarum. The results demonstrate that different families exhibited variable survival rates and 13 families with high disease resistance were obtained. All 13 families exhibited significantly higher survival rates compared with the control, however, some were more significant than others (P<0.01 in 3 families; P<0.05 in 10 families). Of these 13 families, three were derived from the F2 family, one from the F3 family, and two belonged to the first and second gynogenesis generations(G1 and G2). In these six families, disease resistance was high in the parents, with the exception of the F2 family; their survival rate variation coefficients were <10%. Analysis of disease resistance in the three successive generations revealed that, 13 of the 16 disease-resistance families which included 13 families mentioned above and 3 resistant families sereened in 2007 were derived from RS. In conclusion, some F2, F3, G1, and G2 families exhibited enhanced disease resistance inherited from their parents, indicating that the establishment of a disease-resistant strain based on these families is possible.