大菱鲆选育家系抗鳗弧菌性能

Family selection and estimation of disease resistance in turbot, Scophthalmus maximus

基于家系选育技术开展了大菱鲆(Scophthalmus maximus)抗鳗弧菌病选育研究,从2010年构建的37个选育二代家系中选择成活率高的30个家系进行鳗弧菌(Vibrio anguillarum)感染实验,开展对鳗弧菌的抗病性研究。结果表明,不同家系间抗鳗弧菌感染能力存在着显著差异(P<0.05);30个家系中,鳗弧菌感染后,12个家系的存活率达到65%以上,其余家系的存活率则低于65%;通过bCOX回归分析,计算各家系的优势比,优势比最高的5个家系的存活率达到65%以上;对各家系的成活率、优势比和死亡历时差4项指标进行聚类分析,优势比最高且存活率达到65%以上的5个家系聚为一类。综合感染家系的高成活率、高优势比以及聚类分析的结果,选育出5个抗病力较强的优良家系。选育出的抗病力较强的家系可做为抗鳗弧菌选育的核心育种群体,为抗鳗弧菌病的传代选育奠定良好的基础。

Turbot（Scophthalmus maximus）, a flatfish of deep water species, is a high-nutrition and economic valued species and currently cultured widely in China.In recent years, however, serious germ plasm degeneration occurred due to the lack of long-term and effective broodstock management programs, and production of farmed turbot became highly unstable and total output declined gradually. Therefore, the genetic improvement of turbot will be necessary to sustain the industry development. Within a breeding program in aquaculture, The traits which determines the total har-vest yield are highly desirable economic traits, for example, fast-growing, high survival, tolerance to high temperature and disease resistance, etc. The sustainability of turbot culture has been threatened by disease outbreaks and, at present, there is no program in place to minimize such outbreaks. To aid selective breeding for disease resistance traits, in this, study, we conducted a challenge test against Vibrio anguillarum using 30 2nd-generation families that were constructed by consecutive selection for faster growth from a base population. We quantified their disease resistance based on sur-vival and tested for differences among families using an odds ratio. There was a significant difference in disease resis-tance to bacterial infection among families. Twelve families （Family 1, 3, 4, 6, 9, 12, 14, 19, 22, 23, 29, and 30） had high disease resistance with a＆gt;65%survival rate;11 families （Family 8, 10, 13, 16, 18, 20, 21, 24, 25, 27, and 28） had moderately high disease resistance with a 50%-65%survival rate;3 families （Family 2, 7, and 17） had moderate dis-ease resistance with a 35%-50%survival rate;and 4 families （Family 5, 11, 15, and 26） had low disease resistance with a＆lt;35%survival rate. We calculated the odds ratio for disease resistance by b-COX regression analysis, and screened 5 superior families （Family 3, 9, 14, 19, and 23） for third parental generation breeding. The selected families can be used as the core breeding population for turbot resistance to Vibrio anguillarum. In addition, the results of the study also provide a reference for selective breeding for disease resistance in cultured turbot.