辣椒核心种质的构建与优异种质筛选

Establishment of core collection is the basis for further study and efficient utilization of crop germplasm resources. In the previous study 2153 accessions of pepper germplasm were collected and preserved by our team, and their agronomic traits were analysed preliminarily. Based on the 2153 accessions we had and the other 1912 pepper accessions catalogued and kept in the national medium-term genebank of vegetable germplasm resources, the research on establishment of core collection and screening of elite germplasm in pepper will be performed. With the method of information supplementary layer by layer and synthetic application of phenotypic data and SSR molecular data, the sampling strategies to establish a core collection will be studied, sampling scheme and sampling proportion will be optimized, and the preselected core germplasm will be tested in effectiveness. Systematic identification and evaluation of the main agronomic traits, disease resistance traits, stress-resistance traits and quality traits will be carried out on the core collection.The phenotypic database and DNA fingerprinting database of the core collection will be established. This study will construct a core collection holding rich genetic diversity and wide representativeness, and discover a batch of excellent germplasm resources with great applied value. The research will lay foundation for genetic basis development, important functional genes mapping and cloning and genetic improvement in pepper.

核心种质的构建是农作物种质资源深化研究与有效利用的基础。本项目在收集保存2153份辣椒种质、并对其农艺性状进行初步分析的前期研究基础上，结合国家蔬菜种质资源中期库保存编目的1912份辣椒种质，开展辣椒核心种质构建与优异种质筛选。采用逐层补充信息的方法，综合应用表型数据和SSR分子数据，探讨辣椒核心种质取样策略，优化取样方案和取样比例，并对预选核心种质进行有效性检测。系统鉴定和评价核心种质主要农艺性状、抗病性状、抗逆性状和品质性状，建立核心种质表型数据和DNA指纹图谱数据库。通过本研究，构建遗传多样性丰富、代表性广泛的辣椒核心种质，发掘一批有重大应用价值的优异种质资源，为辣椒遗传基础的拓展、重要功能基因的定位与克隆以及辣椒遗传改良奠定基础。

核心种质的构建是农作物种质资源深化研究与有效利用的基础。本项目基于表型数据，开展了辣椒核心种质取样策略研究，优化了分组原则、取样比例和取样方法，获得了最佳取样方案。建立了603份辣椒初始种质表型数据库、512份初级核心种质SRAP数据库和288份二级核心种质SSR数据库，在分子水平上明晰了辣椒种间及种内遗传多样性分布特征。完成603份初始种质疫病抗性鉴定，筛选出高抗种质41份，抗性种质50份，为辣椒抗疫病育种奠定了材料基础。首次在国际上综合应用表型数据和SRAP、SSR分子数据，采用逐层压缩聚类的方法，建立了包含200份核心样品的辣椒核心种质，并进行了有效性检验。该核心种质库有灌木辣椒（C. frutescens）种质3份、C. Chinense种质1份、一年生辣椒（C. annuum）种质196份；国内材料179份、国外材料21份；其中，高抗辣椒疫病种质26份，骨干亲本25份。利用核心种质创制不同遗传背景的特早熟自交系3份、育成抗辣椒疫病、早熟、丰产杂交新品种（组合）5个，并在生产中推广应用。本研究结果为辣椒遗传基础的拓展、重要功能基因的定位与克隆以及辣椒遗传改良奠定了重要基础。