title: The genetic architecture of leaf number and its genetic relationship to flowering time in maize.
abstract: The number of leaves and their distributions on plants are critical factors determining plant architecture in maize (Zea mays), and leaf number is frequently used as a measure of flowering time, a trait that is key to local environmental adaptation. Here, using a large set of 866 maize-teosinte BC2 S3 recombinant inbred lines genotyped by using 19,838 single nucleotide polymorphism markers, we conducted a comprehensive genetic dissection to assess the genetic architecture of leaf number and its genetic relationship to flowering time. We demonstrated that the two components of total leaf number, the number of leaves above (LA) and below (LB) the primary ear, were under relatively independent genetic control and might be subject to differential directional selection during maize domestication and improvement. Furthermore, we revealed that flowering time and leaf number are commonly regulated at a moderate level. The pleiotropy of the genes ZCN8, dlf1 and ZmCCT on leaf number and flowering time were validated by near-isogenic line analysis. Through fine mapping, qLA1-1, a major-effect locus that specifically affects LA, was delimited to a region with severe recombination suppression derived from teosinte. This study provides important insights into the genetic basis of traits affecting plant architecture and adaptation. The genetic independence of LA from LB enables the optimization of leaf number for ideal plant architecture breeding in maize.
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Dan
authors.initials: D
authors.lastname: Li
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Xufeng
authors.initials: X
authors.lastname: Wang
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Xiangbo
authors.initials: X
authors.lastname: Zhang
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Qiuyue
authors.initials: Q
authors.lastname: Chen
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Guanghui
authors.initials: G
authors.lastname: Xu
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Dingyi
authors.initials: D
authors.lastname: Xu
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Chenglong
authors.initials: C
authors.lastname: Wang
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Yameng
authors.initials: Y
authors.lastname: Liang
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Lishuan
authors.initials: L
authors.lastname: Wu
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Cheng
authors.initials: C
authors.lastname: Huang
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Jinge
authors.initials: J
authors.lastname: Tian
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Yaoyao
authors.initials: Y
authors.lastname: Wu
authors.affiliation: National Maize Improvement Center of China, China Agricultural University, Beijing, 100193, China.
authors.forename: Feng
authors.initials: F
authors.lastname: Tian
mesh_terms: D003433:Crosses, Genetic; D035264:Flowers / Q000235:genetics / Q000502:physiology*; D056726:Genetic Association Studies; D007178:Inbreeding; D010641:Phenotype; D020161:Physical Chromosome Mapping; D018515:Plant Leaves / Q000033:anatomy & histology* / Q000235:genetics; D040641:Quantitative Trait Loci / Q000235:genetics; D015203:Reproducibility of Results; D013997:Time Factors; D003313:Zea mays / Q000235:genetics* / Q000502:physiology*
keywords: flowering time; genetic overlap; leaf number; maize (Zea mays); quantitative trait locus (QTL)