title: Genome-wide association study (GWAS) reveals the genetic architecture of four husk traits in maize.
abstract: Maize (Zea mays) husk referring to the leafy outer enclosing the ear, plays an important role in grain production by directly contributing photosynthate and protecting ear from pathogen infection. Although the physiological functions related to husk have been extensively studied, little is known about its morphological variation and genetic basis in natural population.
  
  
  
  Here we utilized a maize association panel including 508 inbred lines with tropical, subtropical and temperate backgrounds to decipher the genetic architecture attributed to four husk traits, i.e. number of layers, length, width and thickness. Evaluating the phenotypic diversity at two different environments showed that four traits exhibit broadly natural variations and moderate levels of heritability with 0.64, 0.74, 0.49 and 0.75 for number, length, width and thickness, respectively. Diversity analysis indicated that different traits have dissimilar responses to subpopulation effects. A series of significantly positive or negative correlations between husk phenotypes and other agronomic traits were identified, indicating that husk growth is coordinated with other developmental processes. Combining husk traits with about half of a million of single nucleotide polymorphisms (SNPs) via genome-wide association study revealed a total of 9 variants significantly associated with traits at P < 1.04 × 10-5, which are implicated in multiple functional categories, such as cellular trafficking, transcriptional regulation and metabolism.
  
  
  
  These results provide instrumental information for understanding the genetic basis of husk development, and further studies on identified candidate genes facilitate to illuminate molecular pathways regulating maize husk growth.
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100094, China.|College of Biological Science and Technology, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Zhenhai
authors.initials: Z
authors.lastname: Cui
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100094, China.
authors.forename: Jinhong
authors.initials: J
authors.lastname: Luo
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100094, China.
authors.forename: Chuangye
authors.initials: C
authors.lastname: Qi
authors.affiliation: College of Biological Science and Technology, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Yanye
authors.initials: Y
authors.lastname: Ruan
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100094, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Li
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100094, China.|College of Agronomy, Shenyang Agricultural University, Shenyang, 110866, China.
authors.forename: Ao
authors.initials: A
authors.lastname: Zhang
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100094, China. yxiaohong@cau.edu.cn.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yang
authors.affiliation: National Maize Improvement Center of China, Beijing Key Laboratory of Crop Genetic Improvement, China Agricultural University, Beijing, 100094, China. yh352@cau.edu.cn.
authors.forename: Yan
authors.initials: Y
authors.lastname: He
mesh_terms: D000704:Analysis of Variance; D016000:Cluster Analysis; D019295:Computational Biology / Q000379:methods; D020869:Gene Expression Profiling; D017343:Genes, Plant; D018745:Genome, Plant; D055106:Genome-Wide Association Study; D010641:Phenotype; D020641:Polymorphism, Single Nucleotide; D040641:Quantitative Trait Loci; D019655:Quantitative Trait, Heritable; D003313:Zea mays / Q000235:genetics*
keywords: GWAS; Genetic architecture; Husk; Maize (Zea mays); SNPs