Genome-wide identification and analysis of heterotic loci in three maize hybrids
Genome-wide identification and analysis of heterotic loci in three maize hybrids
复制标题
三个玉米杂交种杂种优势位点的全基因组鉴定和分析
DOI：
10.1111/pbi.13186
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发表时间：
2020-01-01
影响因子：
13.8
通讯作者：
Huang, Xuehui
中科院分区：
文献类型：
--
作者：
Liu, Hongjun;Wang, Qin;Huang, Xuehui
杂种优势是植物遗传学中的一个重要现象，是作物杂交育种的基础，但许多作物杂种优势产生的基因和位点尚不清楚。在这里，我们提出了一个大规模的遗传分析，使用5360后代从三个精英玉米杂交种，确定628个位点的19个产量相关性状相对较高的映射分辨率。对628个位点的杂种优势模式研究表明，杂合基因型中多为完全-不完全显性（主效）或超显性（次效）的位点，以及双亲优势等位基因的比例几乎相等，是杂种优势强的主要原因。对2225个F-2个体进行的17个杂种优势位点的跟踪研究表明，大多数杂种优势效应在环境间基本稳定，变异较小。对玉米一个主效杂种优势位点（ub 3）的候选基因分析表明，可能存在一些共同的基因对作物杂种优势起作用。这些结果为玉米遗传学研究提供了一个共同的资源，并为植物杂种优势的研究提供了新的启示。
Heterosis, or hybrid vigour, is a predominant phenomenon in plant genetics, serving as the basis of crop hybrid breeding, but the causative loci and genes underlying heterosis remain unclear in many crops. Here, we present a large-scale genetic analysis using 5360 offsprings from three elite maize hybrids, which identifies 628 loci underlying 19 yield-related traits with relatively high mapping resolutions. Heterotic pattern investigations of the 628 loci show that numerous loci, mostly with complete-incomplete dominance (the major one) or overdominance effects (the secondary one) for heterozygous genotypes and nearly equal proportion of advantageous alleles from both parental lines, are the major causes of strong heterosis in these hybrids. Follow-up studies for 17 heterotic loci in an independent experiment using 2225 F-2 individuals suggest most heterotic effects are roughly stable between environments with a small variation. Candidate gene analysis for one major heterotic locus (ub3) in maize implies that there may exist some common genes contributing to crop heterosis. These results provide a community resource for genetics studies in maize and new implications for heterosis in plants.