Genetic control of the leaf angle and leaf orientation value as revealed by ultra-high density maps in three connected maize populations.

Chunhui Li,Yunsu Shi,Yongxiang Li,Yanchun Song,Yu Li,Zhiwu Zhang,Tianyu Wang,Dengfeng Zhang,Edward S Buckler,Rongling Wu

doi:10.1371/journal.pone.0121624

Abstract

Plant architecture is a key factor for high productivity maize because ideal plant architecture with an erect leaf angle and optimum leaf orientation value allow for more efficient light capture during photosynthesis and better wind circulation under dense planting conditions. To extend our understanding of the genetic mechanisms involved in leaf-related traits, three connected recombination inbred line (RIL) populations including 538 RILs were genotyped by genotyping-by-sequencing (GBS) method and phenotyped for the leaf angle and related traits in six environments. We conducted single population quantitative trait locus (QTL) mapping and joint linkage analysis based on high-density recombination bin maps constructed from GBS genotype data. A total of 45 QTLs with phenotypic effects ranging from 1.2% to 29.2% were detected for four leaf architecture traits by using joint linkage mapping across the three populations. All the QTLs identified for each trait could explain approximately 60% of the phenotypic variance. Four QTLs were located on small genomic regions where candidate genes were found. Genomic predictions from a genomic best linear unbiased prediction (GBLUP) model explained 45±9% to 68±8% of the variation in the remaining RILs for the four traits. These results extend our understanding of the genetics of leaf traits and can be used in genomic prediction to accelerate plant architecture improvement.

Highlights

Over the past few decades, plant architecture improvement has greatly increased maize grain yields [1,2,3]
Phenotypic variations were identified for leaf angle (LA), leaf length (LL), leaf width (LW), and leaf orientation value (LOV) within three recombination inbred line (RIL) populations (Table 1)
We performed a literature review on the leaf architecture quantitative trait locus (QTL) as reported in maize in linkage mapping studies [9,10,11,12,13,14, 39] and compared the published QTL with those identified in this study

Summary

Introduction

Over the past few decades, plant architecture improvement has greatly increased maize grain yields [1,2,3]. The leaves of maize hybrids in particular have become more upright. Erect leaves can effectively contribute to the maize grain yield by enhancing light capture for photosynthesis, serving as nitrogen reservoirs for grain filling and enabling denser planting with a higher leaf area index [4,5,6]. Understanding the genetic mechanisms of plant leaf architecture will address a fundamental issue in plant science and facilitate the genetic.

Methods

Results

Conclusion