【摘要】 为了解甜玉米的种质遗传基础,提高甜玉米优良品种选育效率,基于重测序手段进行基因型分型,获得20 648个高质量SNP位点,并基于SNP位点对167份甜玉米自交系进行了遗传多样性和群体遗传结构分析。结果表明:167份甜玉米自交系的期望杂合度为0.09—0.50,平均值0.23;观测杂合度为0.013 3—0.952 1,平均值0.249 5。主等位基因频率的变化范围为0.50—0.95,平均值0.85。多态性信息含量的变化范围为0.095—0.500,平均值0.228。群体遗传结构分析表明:当K=3时,交叉验证错误率最低,结合系统发育树,将167份甜玉米自交系划分为3个类群,该类群划分结果与基于种质来源(热带、亚热带和温带)划分结果基本一致。供试群体中甜玉米自交系整体上遗传变异较为丰富,部分类群有较好的应用潜力。本研究可为甜玉米新品种选育和杂种优势群构建提供技术依据。更多还原

【Abstract】 In order to understand the genetic basis of sweet maize(Zea maysvar.saccharata) germplasm and improve the efficiency of breeding excellent varieties of sweet maize,genotype typing was carried out based on the resequencing method,and 20 648 high-quality SNP loci were obtained. Genetic diversity and population genetic structure analysis were conducted on 167 sweet maize inbred lines based on SNP loci. The results showed that the expected heterozygosity(He) of 167 sweet maize inbred lines ranged from 0. 09 to 0. 50,with an average value of 0. 23,and the observed heterozygosity(Ho) ranged from 0. 013 3 to 0. 952 1,with an average value of0. 249 5. The variation of the main allele frequency(MAF) ranged from 0. 50 to 0. 95,with an average value of0. 85,and that of the polymorphism information content(PIC) ranged from 0. 095 to 0. 500,with an average value of 0. 228. The analysis of population genetic structure showed that whenK= 3,the cross validation error rate was the lowest. Combined with phylogenetic trees,167 sweet maize inbred lines were divided into three groups,which were basically consistent with the classification based on germplasm sources(tropical group,subtropical group,and temperate group). The overall genetic variation of sweet maize inbred lines in the test population was relatively rich,and some groups had good potential for application. This study can provide technical basis for the breeding of new sweet maize varieties and the construction of hybrid dominant groups.更多还原