QTL Analysis of Shading Sensitive Related Traits in Maize under Two Shading Treatments

Liuzheng Yuan,Xiuping Wang,Jihua Tang,Chaohai Li,Rongling Wu

doi:10.1371/journal.pone.0038696

Abstract

During maize development and reproduction, shading stress is an important abiotic factor influencing grain yield. To elucidate the genetic basis of shading stress in maize, an F2:3 population derived from two inbred lines, Zhong72 and 502, was used to evaluate the performance of six traits under shading treatment and full-light treatment at two locations. The results showed that shading treatment significantly decreased plant height and ear height, reduced stem diameter, delayed day-to-tassel (DTT) and day-to-silk (DTS), and increased anthesis-silking interval (ASI). Forty-three different QTLs were identified for the six measured traits under shading and full light treatment at two locations, including seven QTL for plant height, nine QTL for ear height, six QTL for stem diameter, seven QTL for day-to-tassel, six QTL for day-to-silk, and eight QTL for ASI. Interestingly, three QTLs, qPH4, qEH4a, and qDTT1b were detected under full sunlight and shading treatment at two locations simultaneously, these QTL could be used for selecting elite hybrids with high tolerance to shading and high plant density. And the two QTL, qPH10 and qDTS1a, were only detected under shading treatment at two locations, should be quit for selecting insensitive inbred line in maize breeding procedure by using MAS method.

Highlights

Maize (Zea mays L.) is a crop derived from the tropics, and has been imported and cultivated in many areas of higher geographic latitude around the world
The plant height decreased by 8.20 cm (4.00%) and 21.26 cm (7.88%) under shading treatment comparing to CK at the two locations
The plant height of F2:3 populations were lower under shading treatment at the two locations, and there was a wide variation under shading treatment comparing to CK

Summary

Introduction

Maize (Zea mays L.) is a crop derived from the (sub) tropics, and has been imported and cultivated in many areas of higher geographic latitude around the world. Persistent shading has become a restrictive meteorological factor that affects normal plant development and reduces grain yield, especially when accompanied by increasing plant density in many area of the world. Reed et al reported that when plants were shaded during flowering, photosynthesis decreased and kernel abortion increased [1]. Shading in maize during different developmental stages decreases grain yield, and affects the normal development of other agricultural traits, such as internode length reduction [8], delayed flowering and silking time [9], decreased kernel set in the apical ear region or varying degrees of barrenness [10,11], inhibiting silk elongation [12], increased or decreased plant height, delayed new leaves appearance [9], and reduced leaf thickness [13]

Objectives

Methods

Results

Conclusion