The Genetic Control of Grain Protein Content under Variable Nitrogen Supply in an Australian Wheat Mapping Population

Genetic variation has been observed in both protein concentration in wheat grain and total protein content (protein yield). Here we describe the genetic analysis of variation for grain protein in response to nitrogen (N) supply and locate significant genomic regions controlling grain protein components in a spring wheat population. In total, six N use efficiency (NUE) field trials were carried out for the target traits in a sub-population of doubled haploid lines derived from a cross between two Australian varieties, RAC875 and Kukri, in Southern and Western Australia from 2011 to 2013. Twenty-four putative Quantitative Trait Loci (QTL) for protein-related traits were identified at high and low N supply and ten QTL were identified for the response to N for the traits studied. These loci accounted for a significant proportion of the overall effect of N supply. Several of the regions were co-localised with grain yield QTL and are promising targets for further investigation and selection in breeding programs.

研究已在小麦籽粒蛋白质浓度与总蛋白质含量（即蛋白质产量）中均观测到遗传变异。本研究针对春小麦群体中响应氮（N）供给的籽粒蛋白质含量变异开展遗传分析，并定位调控籽粒蛋白质组分的重要基因组区域。2011年至2013年，研究团队于澳大利亚南部与西部，以两个澳大利亚品种RAC875与Kukri杂交获得的双单倍体（doubled haploid，DH）株系亚群体为材料，针对目标性状共计开展了6项氮利用效率（nitrogen use efficiency，NUE）田间试验。在高、低氮供给条件下，共鉴定出24个与蛋白质相关性状关联的推定数量性状位点（Quantitative Trait Loci，QTL）；针对本研究涉及性状的氮响应相关QTL则有10个。上述位点对氮供给的整体效应具有显著贡献。部分上述基因组区域与籽粒产量QTL存在共定位现象，可作为育种项目中后续研究与遗传选择的极具潜力的靶标。