Characterization of correlation between grain moisture and ear rot resistance in maize by QTL meta-analysis

Ear rot (ER) in maize is a prevalent disease worldwide which reduces yield and grain quality. Grain moisture content (GM) is an important factor which impacts the fungal development of ER species. Our purpose was to identify the genomic regions of maize in the control of GM and ER resistance, and the correlations between two traits. A meta-analysis was carried out using 241 quantitative trait loci (QTL) from 29 studies to propose meta-QTL (MQTL) on a high-density genetic linkage map (IBM 2 neighbors 2008). For GM content, 44 MQTL were identified on all chromosomes except for chromosome 9, while 29 MQTL were found for ER resistance, mainly located on chromosomes 3, 6 and 7. Moreover, 14 overlapping domains for GM MQTL and ER MQTL were observed on chromosomes 2, 3, 6 and 7, mainly focused on five active regions (bins 2.08-2.09, 3.04, 3.06, 6.04-6.06 and 7.03-7.03). There were 13 genes in the overlapping domain which could be divided into five classes: stress-related gene, photosystem-related gene, architecture-related gene, dynamic-related gene and seminal-related gene. It was possibly that the five-class genes were simultaneously related with GM and ER.