Genomic Dissection of Leaf Angle in Maize (Zea mays L.) Using a Four-Way Cross Mapping Population.

Junqiang Ding,Hongliang Cheng,Xiantang Li,Luyan Zhang,Yongming Li,Rongrong Huang,Zhimin Li,Jianyu Wu,Bo Zhou,Jiankang Wang,Jiafa Chen,Mingliang Xu

doi:10.1371/journal.pone.0141619

Junqiang Ding, Hongliang Cheng + Show 10 more

Open Access

https://doi.org/10.1371/journal.pone.0141619

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Abstract

Increasing grain yield by the selection for optimal plant architecture has been the key focus in modern maize breeding. As a result, leaf angle, an important determinant of plant architecture, has been significantly improved to adapt to the ever-increasing plant density in maize production over the past several decades. To extend our understanding on the genetic mechanisms of leaf angle in maize, we developed the first four-way cross mapping population, consisting of 277 lines derived from four maize inbred lines with varied leaf angles. The four-way cross mapping population together with the four parental lines were evaluated for leaf angle in two environments. In this study, we reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM). ICIM applies a two-step strategy to effectively separate the cofactor selection from the interval mapping, which controls the background additive and dominant effects at the same time. A total of 14 leaf angle QTL were identified, four of which were further validated in near-isogenic lines (NILs). Seven of the 14 leaf angle QTL were found to overlap with the published leaf angle QTL or genes, and the remaining QTL were unique to the four-way population. This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize.

Highlights

Improving yield by selecting optimal plant architecture is the main objective in maize breeding.In the past several decades, the increasing yield of maize hybrid varieties has been driven by the steadily increase in plant density [1]
We reported linkage maps built in the population and quantitative trait loci (QTL) on leaf angle detected by inclusive composite interval mapping (ICIM)
This study represents the first example of QTL mapping using a four-way cross population in maize, and demonstrates that the use of specially designed four-way cross is effective in uncovering the basis of complex and polygenetic trait like leaf angle in maize

Summary

Introduction

Improving yield by selecting optimal plant architecture is the main objective in maize breeding. In the past several decades, the increasing yield of maize hybrid varieties has been driven by the steadily increase in plant density (i.e., from 30,000 plants per hectare in the 1930s to >80,000 plants per hectare currently) [1]. Genomic Dissection of Leaf Angle Using Four-Way Cross Population significantly improved. Leaf angle was regarded as the major determinant of plant architecture, and has become more significantly upright to adapt the high planting density [1,2]. Erect leaves can effectively maximize photosynthesis by reducing shading and maintaining light capture as canopies became more crowded [3,4,5], which in turn increase yield production in high density cultivation [6,7,8]

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