Identification of QTL for leaf angle at canopy-wide levels in maize

Abstract

Leaf angle (LA) is one of the most important canopy architecture related traits in maize (Zea mays L.). However, the genetic basis of LA at canopy-wide levels is still not completely understood. In this study, one RIL population derived from two parent lines with distinct plant architecture was used for QTL mapping of LA at eight leaves below the tassel across three environments. Fifty-six QTL for LA of eight leaves were identified in single environment analysis and 44 QTL for LA of eight leaves were detected in joint analysis. Among them, nine common QTL were identified because they were detected for LA more than 1 leaves or in 2 or 3 environments. The single QTL could explain 1.29–20.14% of the phenotypic variation with affecting LA of 1–8 leaves, included qLA5.1 affected LA of all eight leaves, qLA3.1 affected LA of the upper leaves (1stLA–4thLA), and qLA9.1 affected LA of the lower leaves (5thLA–8thLA). Furthermore, the 8thLA was mainly affected by major and minor QTL; the 1stLA, 4thLA and 5thLA were affected by major QTL, minor QTL and epistatic interactions; the other four LAs were simultaneously affected by major QTL, minor QTL, epistatic interactions and environments, inferred that the genetic architecture of LA of eight leaves was different. These results provide a comprehensive understanding of genetic basis of LA at canopy-wide levels, which will be helpful to design the ideal plant architecture in maize.