title: Genome-wide association analysis for nine agronomic traits in maize under well-watered and water-stressed conditions.
abstract: Drought can cause severe reduction in maize production, and strongly threatens crop yields. To dissect this complex trait and identify superior alleles, 350 tropical and subtropical maize inbred lines were genotyped using a 1536-SNP array developed from drought-related genes and an array of 56,110 random SNPs. The inbred lines were crossed with a common tester, CML312, and the testcrosses were phenotyped for nine traits under well-watered and water-stressed conditions in seven environments. Using genome-wide association mapping with correction for population structure, 42 associated SNPs (P ≤ 2.25 × 10(-6) 0.1/N) were identified, located in 33 genes for 126 trait × environment × treatment combinations. Of these genes, three were co-localized to drought-related QTL regions. Gene GRMZM2G125777 was strongly associated with ear relative position, hundred kernel weight and timing of male and female flowering, and encodes NAC domain-containing protein 2, a transcription factor expressed in different tissues. These results provide some good information for understanding the genetic basis for drought tolerance and further studies on identified candidate genes should illuminate mechanisms of drought tolerance and provide tools for designing drought-tolerant maize cultivars tailored to different environmental scenarios.
authors.affiliation: National Key Laboratory of Crop Genetic Improvement, Huazhong Agricultural University, Wuhan, 430070, China.
authors.forename: Yadong
authors.initials: Y
authors.lastname: Xue
authors.forename: Marilyn L
authors.initials: ML
authors.lastname: Warburton
authors.forename: Mark
authors.initials: M
authors.lastname: Sawkins
authors.forename: Xuehai
authors.initials: X
authors.lastname: Zhang
authors.forename: Tim
authors.initials: T
authors.lastname: Setter
authors.forename: Yunbi
authors.initials: Y
authors.lastname: Xu
authors.forename: Pichet
authors.initials: P
authors.lastname: Grudloyma
authors.forename: James
authors.initials: J
authors.lastname: Gethi
authors.forename: Jean-Marcel
authors.initials: JM
authors.lastname: Ribaut
authors.forename: Wanchen
authors.initials: W
authors.lastname: Li
authors.forename: Xiaobo
authors.initials: X
authors.lastname: Zhang
authors.forename: Yonglian
authors.initials: Y
authors.lastname: Zheng
authors.forename: Jianbing
authors.initials: J
authors.lastname: Yan
mesh_terms: D000383:Agriculture; D003681:Dehydration; D055106:Genome-Wide Association Study; D015810:Linkage Disequilibrium / Q000235:genetics; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide / Q000235:genetics; D019655:Quantitative Trait, Heritable; D013312:Stress, Physiological; D013785:Thailand; D014867:Water; D003313:Zea mays / Q000033:anatomy & histology / Q000235:genetics* / Q000502:physiology*
chemical_list: D014867:Water