普通小麦氮素利用效率相关性状全基因组关联分析

Genome-wide association study of nitrogen use efficiency related traits in common wheat(Triticum aestivum L.)

氮元素在粮食作物生长和发育过程起着不可替代的作用。发掘氮素利用效率相关基因对于提升小麦产量、减少环境污染具有重要意义。植株根系构型(root system architecture,RSA)代表着根系的结构及空间造型,显著受氮素水平影响。本研究在正常供氮和缺氮两种氮素水平下,对160份来自黄淮冬麦区和北部冬麦区普通小麦品系的根系构型相关性状(总根长、总根表面积、总根体积、平均根直径和根尖数)进行统计,并结合小麦660K SNP(single nucleotide polymorphism)芯片基因分型数据对根系相关性状的相对值进行全基因组关联分析,以期发掘氮素利用效率相关位点。本研究检测到34个与氮素利用效率显著关联的SNP位点,可解释6.9%~15.4%的表型变异。关联位点在所有染色体均有分布,主要集中于1A、2B、3B、5B、6A、6B和7A染色体。11个位点与已报道位点重叠或接近,其他23个位点可能为新的位点。另外,在3B染色体上发现一个编码E3泛素连接酶的候选基因。

Nitrogen application plays an important role in plant growth and development.Exploring genetic loci related to nitrogen use efficiency is of great significance for improving wheat yield and reducing environmental pollution.Root system architecture(RSA)determined the composition of plant root system,and significantly affected by nitrogen level.Under different nitrogen levels(deficiency and normal),160 winter wheat accessions from the Huanghuai valley and Northern winter wheat region were counted for their root architecture-related traits(total root length,total root surface area,total root volume,average root diameter,and root tip number).Genotype was analyzed using 660K SNP(single nucleotide polymorphism)data.Genome-wide association study(GWAS)was employed to identify the relevant loci for nitrogen use efficiency.A total of 34 associated loci were detected,which explained 6.9%–15.4%of the phenotypic variation.These loci distributed on all chromosomes and mainly centered on chromosomes 1A,2B,3B,5B,6A,6B,and 7A,respectively.Among the loci detected in this study,11 loci overlapped or were close to the reported ones,while the other 23 might be novel loci.In addition,we explored a candidate gene encoding the E3 ubiquitin ligase.This study is of great significance for understanding the genetic mechanism of nitrogen utilization and breeding high-yield wheat varieties.