中国黄淮海地区玉米杂种优势候选位点的鉴定

Identification of Candidate Loci Associated with Maize Heterosis in Huang-Huai-Hai Region of China

通过对全基因组重测序数据分析发现120 122个高质量In Del和SNP变异位点,通过这些位点可以将具有不同遗传背景的285份玉米自交系划分为9大类群,包括黄淮海地区两大杂种优势群PA和SPT群。检测PA和SPT群间自交系基因型频率的分布和差异发现,1 251个杂种优势候选位点不均匀分布在玉米10条染色体上,其中,675个位点与42个已报道的杂种优势相关QTLs一致。基于候选位点,对部分黄淮海地区的主栽杂交品种进行杂合性分析,In Del和SNP结果均表明,这些位点的杂合性显著高于其他区域,研究结果验证了本研究获得的候选区域的可靠性,表明这些候选位点的杂合性已被广泛的运用于育种过程中。

By maize re-sequencing data that deposited in NCBI, more than 120 122 DNA variations of InDel and SNP were called from 285 diverse inbred lines. Analysis of genetic distances showed population stratification, and nine genetically distinct clusters were grouped, including PA and SPT groups, which were two predominant heterotic groups used in commercial hybrid breeding in Huang-huai-hai region. The utility of InDel and SNP variations for performing genome-wide scanning for individuals from PA and SPT groups had found that 1 251 loci had distributed unevenly on 10 chromosomes in maize. Noticeably, six hundred and seventy-five newly identified loci had bracketed the 42 previously reported QTL from several previous studies for heterosis. Moreover, based on the candidate sites, the heterozygosis of main hybrid varieties in Huang-huai-hai region were analyzed, the results of In- del and SNP exhibited the significant higher loci heterozygosis near candidate loci, which decreased when span to flanking regions, suggesting that the newly identified heterozygosis had been inadvertently selected during maize heterosis breeding. The results provided the more efficient and targeted use of the genetic loci for hybrid breeding in maize.