中国对虾生长及WSSV抗性遗传进展最大化研究

The main goal of breeding programs is to maximize genetic gain. While, researches were very weak on how to establish equilibrium between genetic gain and inbreeding control in aquatic animal breeding populations, espetially in shrimp. This project would take Chinese shrimp(Fenneropenaeus chinensis) as a research object, making use of linear mixed model, Bayesian method to build exact breeding analysis models based on the pedgree and data of eight generations accumulated previously from the breeding core group. Then the genetic parameters of growth and WSSV resistance and genetic gain after multi-generation selection could be evaluated accurately. A simulation study will be done to compare the genetic gain and inbreeding level of four selection methods and three mating ways based on the optimum contribution (OC) theory, selecting the optimum selecting and mating strategies for F. chinensis families and individuals. To evaluate the perfomance of OC selection, it will be applied and disseminated in F. chinensis breeding core group. This project is supposed to establish exact genetic evaluation technique of growth and resistance, further improve genetic gain by optimum selection and mating strategy under limited inbred level. It will establish technical foundation for upgrading breeding technology, promoting and culturing fine varieties in aquatic commercial animals.

实现遗传进展最大化是育种工作的主要目标，然而如何在育种群体中建立遗传进展和近交控制之间的平衡在水产动物尤其是虾类中的研究还很薄弱。本项目拟以中国对虾为研究对象，根据前期积累的中国对虾育种群体8代系谱及性能测定数据，利用混合线性模型、贝叶斯等方法，建立适合中国对虾生长和WSSV抗性的精确育种分析模型，准确评估生长和WSSV抗性的遗传参数及多代选择后的遗传进展，利用最佳遗传贡献（Optimum Contribution, OC）理论，比较4种OC选种方法和3种配种策略在遗传进展和近交水平上的差异，筛选中国对虾家系和个体的选种、配种最优化策略，并在中国对虾育种核心群中推广应用，评估OC选种方法的准确性和可靠性。本项目有望建立中国对虾生长和抗病性状的精确评估技术，在限定的近交水平下，通过优化选种和配种技术进一步提高遗传进展，为育种技术升级、推广和加速水产经济动物优良品种培育奠定技术基础。

实现遗传进展最大化是育种工作的主要目标，然而如何在育种群体中建立遗传进展和近交控制之间的平衡在水产动物尤其是虾类中的研究还很薄弱。本项目利用中国对虾育种群体G0-G10代生长及WSSV抗性性能测定数据及系谱，分析并筛选年份、性别、测试环境、共同环境效应等固定和随机效应因子，建立了中国对虾体重遗传评估模型1个，准确评估了中国对虾多世代选育后收获体重的相关表型及遗传参数，中国对虾多世代收获体重遗传力为0.131±0.029，共同环境效应0.125±0.012，获得了中国对虾育种核心群多世代生长性状遗传进展，与韩国野生群体相比，G10代核心群遗传进展为28.40%；建立中国对虾WSSV抗性遗传评估模型1个，准确评估了中国对虾WSSV抗性的相关表型及遗传参数，中国对虾抗WSSV存活时间遗传力为0.031±0.021，共同环境效应0.173±0.012，获得中国对虾育种核心群多世代选择后WSSV抗性的遗传进展，与韩国野生群体相比，G10代核心群WSSV存活时间遗传进展为8.49%；同时，本项目首次在对虾中探索了最佳遗传贡献选择的应用，制定了基于遗传算法的虾类选种、配种方案，比较基于优化遗传贡献选择和选择指数法所获得的收获体重的遗传进展和近交水平差异，发现与选择指数法相比，最佳遗传贡献选择可在控制近交的同时实现遗传进展的最大化。本项目的开展为中国对虾育种技术升级、推广和加速中国对虾优良品种培育奠定了技术基础。