Genetic and Quantitative Trait Locus Analysis of Cell Wall Components and Forage Digestibility in the Zheng58 × HD568 Maize RIL Population at Anthesis Stage.

Kun Li,Yujin Wu,Feiqian Ma,Zhifang Liu,Qi Wang,Changling Huang,Xiaojiao Hu,Hongwu Wang

doi:10.3389/fpls.2017.01472

Abstract

The plant cell wall plays vital roles in various aspects of the plant life cycle. It provides a basic structure for cells and gives mechanical rigidity to the whole plant. Some complex cell wall components are involved in signal transduction during pathogenic infection and pest infestations. Moreover, the lignification level of cell walls strongly influences the digestibility of forage plants. To determine the genetic bases of cell wall components and digestibility, quantitative trait locus (QTL) analyses for six related traits were performed using a recombinant inbred line (RIL) population from a cross between Zheng58 and HD568. Eight QTL for in vitro neutral detergent fiber (NDF) digestibility were observed, out of which only two increasing alleles came from HD568. Three QTL out of ten with alleles increasing in vitro dry matter digestibility also originated from HD568. Five–ten QTL were detected for lignin, cellulose content, acid detergent fiber, and NDF content. Among these results, 29.8% (14/47) of QTL explained >10% of the phenotypic variation in the RIL population, whereas 70.2% (33/47) explained ≤10%. These results revealed that in maize stalks, a few large-effect QTL and a number of minor-effect QTL contributed to most of the genetic components involved in cell wall biosynthesis and digestibility.

Highlights

The plant cell wall is an amorphous matrix that surrounds the cell membrane
Zheng58 originated from BSSS group, HD568 came from Tangsipingtou (TSPT) germplasm which is a traditional heterotic group used in maize breeding of China
Among the six investigated traits, significant differences were observed between the two parental lines only in in vitro neutral detergent fiber digestibility (IVNDFD) and in vitro dry matter digestibility (IVDMD)

Summary

Introduction

The plant cell wall is an amorphous matrix that surrounds the cell membrane. Plant cell walls provide the basic mechanical support that allows plants to stand upright. Microbial infection usually induces lignification of the cell wall, which protects plants from further harm. Cell wall architecture plays important roles in plant responses to various abiotic stresses, such as drought, flooding, heat, cold, and salt and is essential in stress sensing and signal transduction (Gall et al, 2015). The cell walls of forage plants are the main resources for animal feeding. Lignocellulose biomass is considered to be a source of renewable energy for the production of biofuel (Bhalla et al, 2013)

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