Genome-wide association study reveals genomic regions controlling root and shoot traits at late growth stages in wheat
Genome-wide association study reveals genomic regions controlling root and shoot traits at late growth stages in wheat
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DOI：
10.1093/aob/mcz041
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发表时间：
2019-11-04
期刊：
影响因子：
4.2
通讯作者：
Jing, Ruilian
中科院分区：
文献类型：
--
作者：
Li, Long;Peng, Zhi;Jing, Ruilian
背景与目的根系形态对可持续农业具有重要意义，但根系性状的遗传基础及其与茎部性状的关系尚不清楚。本研究旨在探讨小麦生育后期根系性状的遗传基础及其对茎部性状的影响。方法以323份小麦材料为研究对象，通过田间试验研究了孕穗期和灌浆中期根系性状、株高（PH）、冠层温度（CT）和单株产量（YPP）等地上部性状的表型差异，并利用小麦660K SNP阵列进行了全基因组关联研究。结果根系较深的植株比根系较浅的植株有较低的CT值和较高的YPP值，但根系干重与茎部性状无显著相关。通过混合线性模型检测到93个显著相关位点（SALs），其中3个是与孕穗期和灌浆中期根系深度相关的轮毂SALs (Co-6A、Co-6B和Co-6D)，以及CT和YPP。微植管系统扫描结果表明，3种SALs的致病基因可能在田间调控根系伸长。通过连锁不平衡分析证实了根深与PH之间的遗传独立性。结合根深和PH有利标记等位基因（FMAs）的基因型的YPP显著高于其他基因型，表明根深和株高较短是分子标记辅助育种中构建靶等位基因的适宜性状。结论本研究结果为根系发育后期根系性状的功能基因发现提供了有价值的基因组区域，增强了对根系与茎部性状相关性的认识，为根系形态和育种分子设计的深入研究奠定了基础。
Background and Aims Root system morphology is important for sustainable agriculture, but the genetic basis of root traits and their relationship to shoot traits remain to be elucidated. The aim of the present study was to dissect the genetic basis of root traits at late growth stages and its implications on shoot traits in wheat.Methods Among 323 wheat accessions, we investigated phenotypic differences in root traits at booting and mid-grain fill stages in PVC tubes, shoot traits including plant height (PH), canopy temperature (CT) and grain yield per plant (YPP) in a field experiment, and performed a genome-wide association study with a Wheat 660K SNP Array.Key Results Deep-rooted accessions had lower CT and higher YPP than those with shallow roots, but no significant relationship was identified between root dry weight and shoot traits. Ninety-three significantly associated loci (SALs) were detected by the mixed linear model, among which three were hub SALs (Co-6A, Co-6B and Co-6D) associated with root depth at both booting and mid-grain fill stages, as well as CT and YPP. Minirhizotron system scanning results suggested that the causal genes in the three SALs may regulate root elongation in the field. The heritable independence between root depth and PH was demonstrated by linkage disequilibrium analysis. The YPP was significantly higher in genotypes which combined favourable marker alleles (FMAs) for root depth and PH, suggesting that a deep root and shorter plant height are suitable traits for pyramiding target alleles by molecular marker-assisted breeding.Conclusions These results uncovered promising genomic regions for functional gene discovery of root traits in the late growth period, enhanced understanding of correlation between root and shoot traits, and will facilitate intensive study on root morphology and breeding through molecular design.