Hybrids with low grain moisture (GM) at harvest are specially required in mid- to short-season environments. One of the most important factors determining this trait is field grain drying rate (FDR). To produce hybrids with low GM at harvest, inbred lines can be obtained through selection for either GM or FDR. Thus, a single-cross population (181 F (2:3)-generation plants) of two divergent inbred lines was evaluated to locate QTL affecting GM at harvest and FDR as a starting point for marker assisted selection (MAS). Moisture measurements were made with a hand-held moisture meter. Detection of QTL was facilitated with interval mapping in one and two dimensions including an interaction term, and a genetic linkage map of 122 SSR loci covering 1,557.8 cM. The markers were arranged in ten linkage groups. QTL mapping was made for the mean trait performance of the F (2:3) population across years. Ten QTL and an interaction were associated with GM. These QTL accounted for 54.8 and 65.2% of the phenotypic and genotypic variation, respectively. Eight QTL and two interactions were associated with FDR accounting for 35.7 and 45.2% of the phenotypic and genotypic variation, respectively. Two regions were in common between traits. The interaction between QTL for GM at harvest had practical implications for MAS. We conclude that MAS per se will not be an efficient method for reducing GM at harvest and/or increasing FDR. A selection index including both molecular marker information and phenotypic values, each appropriately weighted, would be the best selection strategy.

Associations between quantitative trait loci (QTL) and corn (Zea mays L.) percentage grain moisture at harvest (GM) have been reported in several studies; however, stability of QTL across breeding populations has depended upon the genetic backgrounds evaluated, the generation of progeny evaluated (inbred lines per se (LP) or test crosses (TC)), and/or the environments within which populations were evaluated. Marker assisted breeding for improved GM in corn should be aided greatly by identification of QTL for GM that are stable across environments, genetic backgrounds and generations. One aid toward this end is Meta-analysis. QTL associated with GM were identified in a TC population planted at five locations. Meta-analysis was performed by evaluating 184 QTL assembled from LP (146 QTL) and TC (38 QTL) data consolidated from literature. Eight MetaQTL were associated with GM in both LP and TC populations when LP and TC data were evaluated independently. Thirty-four MetaQTL were associated with GM when LP and TC data were evaluated jointly. MetaQTL identified in this study should be stable in marker assisted breeding programs since QTL were associated with improved GM across multiple environments, genotypes and populations.