基于SNP标记揭示中国鲜食玉米品种的遗传多样性  

Genetic diversity analysis of Chinese fresh corn hybrids using SNP Chips

作　　者：肖颖妮 于永涛[1] 谢利华 祁喜涛[1] 李春艳[1] 文天祥[1] 李高科[1] 胡建广[1] XIAO Ying-Ni;YU Yong-Tao;XIE Li-Hua;QI Xi-Tao;LI Chun-Yan;WEN Tian-Xiang;LI Gao-Ke;HU Jian-Guang(Crop Research Institute,Guangdong Academy of Agricultural Sciences/Key Laboratory of Crops Genetics and Improvement of Guangdong Province,Guangzhou 510640,Guangdong,China)

机构地区：[1]广东省农业科学院作物研究所/广东省农作物遗传改良重点实验室,广东广州510640

出　　处：《作物学报》2022年第6期1301-1311,共11页Acta Agronomica Sinica

基　　金：国家重点研发计划项目(2018YFD0100106,2018YFD0200700);广东省重点领域研发计划项目(2018B020202008);广东省乡村振兴战略专项(粤财农[2020]100号);广东省农业科学院学科团队建设项目(202115TD);广东省农业种业共性关键技术创新团队项目(2020KJ106);广州市科技计划项目(201804020081);科技创新战略-高水平农科院建设项目(R2017YJ-YB1002,R2018PY-QF006,R2018QD-048)资助。

摘　　要：中国已经成为全球鲜食玉米最主要生产和消费国家之一,解析我国鲜食玉米品种之间的遗传多样性和亲缘关系,对品种鉴定和品种培育具有重要的指导意义。本研究利用Illumina Maize 6K芯片对全国范围内的385个鲜食玉米品种进行全基因组扫描,了解群体结构,划分种质类群,估算品种间的遗传距离,揭示其遗传多样性。结果表明,5067个SNP标记在385个鲜食玉米品种中基因多样性平均0.406,变幅为0.097~0.500;多态信息含量(polymorphism information content, PIC)平均0.319,变幅为0.092~0.375。通过PCA分析和群体遗传结构分析一致表明,本研究所收集的品种主要划分为3个类群,分别为糯玉米类群(糯玉米和甜糯玉米,共185个品种)、温带甜玉米类群(123个品种)和热带甜玉米类群(77个品种)。两两品种间的遗传距离在0.132~0.472之间,平均值为0.37。通过FST分析检测到不同类群间有160个区域受到强烈选择,其中包括4个玉米籽粒淀粉合成途径的关键基因(sh2、su1、su2和wx1),进一步利用分子标记验证了sh2和DGAT1-2两个位点在鲜食玉米群体不同选择模式。本研究为我国鲜食玉米品种选育和改良提供了重要的理论指导。China is a major fresh corn production and consumption country in the world. Assessment of genetic diversity and relationships among fresh corn hybrids in China has great benefit for hybrid identification and breed cultivation. In this study, an Illumina Maize 6K chip was employed to perform genome-wide scanning for the population structure and genetic distance of 385fresh corn hybrids nationwide. The results showed that the average genetic diversity of 5067 SNP markers in 385 fresh corn hybrids was 0.406, with a range of 0.097–0.500. The average polymorphic information content(PIC) was 0.319, with a range of 0.092–0.375. The results of PCA and population genetic structure analysis revealed that the hybrids were mainly divided into three groups, which were non-sweet corn group(185 varieties), temperate sweet corn group(123 varieties), and tropical sweet corn group(77 varieties). The genetic distance between any two hybrids ranged from 0.132 to 0.472, with an average of 0.37. A total of 160 genome regions indicated strong population differentiation among different groups following FST analysis. Four key genes(sh2, su1, su2, and wx1) of starch synthesis pathway in maize grains were detected. Two candidate genes(sh2 and DGAT1-2)demonstrated different selection patterns in fresh corn groups and were validated using molecular markers. These results provide important theoretical guidance for the breeding and improvement of fresh corn varieties in China.

关 键 词：鲜食玉米 遗传多样性 群体结构 遗传距离 选择位点 

分 类 号：S513[农业科学—作物学]