作物学报2025，Vol.51Issue(8)：2020-2032,13.DOI:10.3724/SP.J.1006.2025.51020
小麦幼苗根系性状全基因组关联分析及TaSRL-3B优异等位基因发掘
Genome-wide association study of root traits in wheat seedlings and identifica-tion of a superior allele at TaSRL-3B
摘要
Abstract
The root system is the primary organ responsible for water and nutrient uptake in wheat,and its morphological charac-teristics are closely associated with yield and tolerance to abiotic stress.Therefore,identifying genetic loci and favorable alleles that control root morphology is of great importance for wheat improvement.In this study,277 wheat accessions were evaluated using a gel-chamber-based observation method to characterize eight root morphological traits at the seedling stage,including total root length,root surface area,and root angle.Based on genotyping with the Wheat 660K SNP Array,a genome-wide association study(GWAS)was performed using three models(GLM,MLM,and FarmCPU),leading to the identification of 52 associated loci.Among them,six pleiotropic loci(Loci17,Loci20,Loci22,Loci38,Loci46,and Loci47)were located on chromosomes 3A,3B,3D,5A,6A,and 6B,respectively.Within Loci20,the candidate gene TaSRL-3B,associated with root morphology,was cloned.This gene has a full-length sequence of 1089 bp,lacks introns,and contains a conserved NAC domain between amino acids 78 and 235.A 20-bp insertion/deletion(InDel717)in the coding region of TaSRL-3B caused a frameshift mutation and showed strong linkage(R2=0.84)with the candidate SNP(AX-108758584)in Loci20.Accessions carrying the TaSRL-3BIn allele exhibited significantly greater maximum root length,total root length,and root surface area compared to those with the TaSRL-3BIn.A backcross intro-gression line population(BC3F5)was developed using Lumai 14(LM14,carrying TaSRL-3BDel as the recurrent parent and Shaanhe 6(SH6,carrying TaSRL-3BIn as the donor.A molecular marker based on InDel717 was used to identify five near-isogenic lines(NILs)carrying TaSRL-3BIn from this population.Compared to LM14,these lines showed significant improvements in maximum root length,total root length,root surface area,and root volume,further confirming the role of TaSRL-3B in shaping seedling root morphology.Notably,the frequency of the long-root allele TaSRL-3BIn has declined in modern Chinese cultivars compared to landraces.This study provides valuable insights into the genetic regulation of wheat root traits and supports the ge-netic improvement of root systems for enhanced wheat performance.关键词
小麦/幼苗/根系形态/全基因组关联分析/候选基因Key words
wheat/seedling/root morphology/genome-wide association analysis/candidate gene引用本文复制引用
蔡金珊,李超男,王景一,李宁,柳玉平,景蕊莲,李龙,孙黛珍..小麦幼苗根系性状全基因组关联分析及TaSRL-3B优异等位基因发掘[J].作物学报,2025,51(8):2020-2032,13.基金项目
本研究由国家重点研发计划项目(2022YFD1200201)和财政部和农业农村部国家现代农业产业技术体系建设专项(CARS-03-5)资助.This study was supported by the National Key R&D Program of China(2022YFD1200201)and the China Agriculture Research System of MOF and MARA(CARS-03-5). （2022YFD1200201）
