Intraspecific variation of residual heterozygosity and its utility for quantitative genetics studies in maize
作者单位：National Key Laboratory of Crop Genetic ImprovementHuazhong Agricultural University College of InformaticsHuazhong Agricultural University National Maize Improvement Center of ChinaBeijing Key Laboratory of Crop Genetic ImprovementChina Agricultural University
会议名称：《2016年全国植物生物学大会》
会议日期：2016年
关 键 词：maize residual heterozygosity heterogeneous inbred family QTL mapping recombinant inbred lines
摘 要：Residual heterozygosity(RH) in advanced inbred progenies of plants benefits quantitative trait locus(QTL) mapping studies. However,knowledge of factors affecting its genome-wide distribution remains limited. In this study,a collection of maize heterogeneous inbred family(HIF) lines was assembled,comprising a set of 12 recombinant inbred line(RIL) populations with 2,196 lines that were genotyped using a Maize50 K commercial SNP chip. Each population revealed 505 to 2095 RH intervals which collapsed to 18,615 unique RH intervals across 12 populations,covering 94.8% of the maize genome. On average,a given RH region was present in 5 different individuals. We found that some genomic regions were enriched in RH segments and seven RH hotspots were identified in the genome. The RH patterns varied significantly across populations,presumably reflecting differences in genetic backgrounds and 8 QTLs were identified for the RH hotspots in and of themselves. QTL fine mapping of kernel tocopherol content demonstrated a potential of the HIF library to efficiently map QTL locations,down to approximately ≤ 1Mb-resolution based on publicly available information for the 12 populations. The library of HIF lines gave us new insights into the RH landscape and its intraspecific variation and provides a useful resource for QTL cloning of agronomic important traits in maize.