title: Complex genetic architecture underlies maize tassel domestication.
abstract: Maize (Zea mays) tassels underwent profound morphological changes during maize domestication and improvement. Although a number of genes affecting maize inflorescence development have been identified, the genetic basis of the morphological changes in maize tassels since domestication is not well understood. Here, using a large population of 866 maize-teosinte BC2S3recombinant inbred lines genotyped using 19 838 single nucleotide polymorphism (SNP) markers, we performed high-resolution quantitative trait locus (QTL) mapping for five tassel morphological traits. We showed that the five tassel traits were associated with different genetic architecture features. Known genes for maize inflorescence development identified by mutagenesis were significantly enriched in the tassel trait QTLs, and many of these genes, including ramosa1 (ra1), barren inflorescence2 (bif2), unbranched2 (ub2), zea floricaula leafy2 (zfl2) and barren stalk fastigiate1 (baf1), showed evidence of selection. An in-depth nucleotide diversity analysis at the bif2 locus identified strong selection signatures in the 5'-regulatory region. We also found that several known flowering time genes co-localized with tassel trait QTLs. A further association analysis indicated that the maize photoperiod gene ZmCCT was significantly associated with tassel size variation. Using near-isogenic lines, we narrowed down a major-effect QTL for tassel length, qTL9-1, to a 513-kb physical region. These results provide important insights into the genetic architecture that controls maize tassel evolution.
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Xu
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Xufeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Huang
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Dingyi
authors.initials: D
authors.lastname: Xu
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Jinge
authors.initials: J
authors.lastname: Tian
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Qiuyue
authors.initials: Q
authors.lastname: Chen
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Chenglong
authors.initials: C
authors.lastname: Wang
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Yameng
authors.initials: Y
authors.lastname: Liang
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Yaoyao
authors.initials: Y
authors.lastname: Wu
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Xiaohong
authors.initials: X
authors.lastname: Yang
authors.affiliation: National Maize Improvement Center, China Agricultural University, Beijing, 100193, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Tian
mesh_terms: D000071278:Domestication; D035264:Flowers / Q000033:anatomy & histology* / Q000235:genetics / Q000502:physiology; D017343:Genes, Plant; D007178:Inbreeding; D056626:Inflorescence / Q000235:genetics / Q000254:growth & development; D010641:Phenotype; D020161:Physical Chromosome Mapping; D040641:Quantitative Trait Loci / Q000235:genetics; D019655:Quantitative Trait, Heritable; D011995:Recombination, Genetic / Q000235:genetics; D012641:Selection, Genetic; D013997:Time Factors; D003313:Zea mays / Q000033:anatomy & histology* / Q000235:genetics*
keywords: candidate gene; genetic architecture; maize; quantitative trait locus (QTL); tassel