Wenqiang Li, Yanhui Yu, Luxi Wang, Yun Luo, Yong Peng, Yuancheng Xu, Xiangguo Liu, Shenshen Wu, Liumei Jian, Jieting Xu, Yingjie Xiao, Jianbing Yan

Plant Biotechnol J.; 2021 Jun;19(6):1195-1205.  doi: 10.1111/pbi.13541. Epub 2021 Feb 11.

Abstract

Low grain moisture at harvest is crucial for safe production, transport and storage, but the genetic architecture of this trait in maize (Zea mays) remains elusive. Here, we measured the dynamic changes in grain moisture content in an association-mapping panel of 513 diverse maize inbred lines at five successive stages across five geographical environments. Genome-wide association study (GWAS) revealed 71 quantitative trait loci (QTLs) that influence grain moisture in maize. Epistatic effects play vital roles in the variability in moisture levels, even outperforming main-effect QTLs during the early dry-down stages. Distinct QTL-environment interactions influence the spatio-temporal variability of maize grain moisture, which is primarily triggered at specific times. By combining genetic population analysis, transcriptomic profiling and gene editing, we identified GRMZM5G805627 and GRMZM2G137211 as candidate genes underlying major QTLs for grain moisture in maize. Our results provide insights into the genetic architecture of dynamic changes in grain moisture, which should facilitate maize breeding.

See: https://pubmed.ncbi.nlm.nih.gov/33386670/

Figure 2: Genetic basis of the spatio‐temporal variation in moisture content. (a) Manhattan plot of GWAS for grain moisture. The 71 significant loci that influence moisture content or AUDDC value are indicated by coloured dots. The colours (orange, red and blue) represent the three classes of significant loci that interact with the environment at the early or late stage. (b) Variability of Q × E variance during the dehydration process. In the heatmap, the colour indicates how this QTL interacts with the environment, including early Q × E, later Q × E, and constitutive Q × E. The colour density indicates the variance explained by Q × E at a specific stage of dehydration. (c) Epistasis between 71 significant loci. In the circle plot, the coloured lines connecting two genomic locations indicate significant epistasis between two GWAS loci. The colour indicates the dehydration stage in which the significance of epistasis was detected.