Association mapping for phenology and plant architecture in maize shows higher power for developmental traits compared with growth influenced traits

Plant architecture, phenology and yield components of cultivated plants have repeatedly been shaped by selection to meet human needs and adaptation to different environments. Here we assessed the genetic architecture of 24 correlated maize traits that interact during plant cycle. Overall, 336 lines were phenotyped in a network of 9 trials and genotyped with 50K single-nucleotide polymorphisms. Phenology was the main factor of differentiation between genetic groups. Then yield components distinguished dents from lower yielding genetic groups. However, most of trait variation occurred within group and we observed similar overall and within group correlations, suggesting a major effect of pleiotropy and/or linkage. We found 34 quantitative trait loci (QTLs) for individual traits and six for trait combinations corresponding to PCA coordinates. Among them, only five were pleiotropic. We found a cluster of QTLs in a 5 Mb region around Tb1 associated with tiller number, ear row number and the ...栽培植物的株型、物候期与产量构成因子，长期以来均通过人工选择塑造，以契合人类需求并适应各异的生长环境。本研究针对玉米生长周期内相互关联的24个农艺性状，解析其遗传结构。研究共对336份玉米自交系开展表型鉴定，试验覆盖9个不同环境的联合试验网络，并采用50K单核苷酸多态性（single-nucleotide polymorphisms）标记进行基因型分型。物候期是区分不同遗传类群的首要因素，而产量构成因子则可将马齿型玉米与低产遗传类群区分开来。然而，绝大多数性状变异均存在于类群内部；同时我们观察到类群间与类群内的性状关联模式高度相似，这表明多效性（pleiotropy）和/或连锁（linkage）发挥了主导作用。本研究共鉴定到调控单个性状的34个数量性状位点（quantitative trait loci, QTLs），以及对应主成分分析（PCA）坐标的6个性状组合关联位点。其中仅5个位点具有多效性。我们在以Tb1基因为中心的5 Mb基因组区域内，发现了一个QTL簇，该位点簇与分蘖数、穗行数以及……相关联。