Map Integration of QTLs for Grain Yield and Its Related Traits in Maize

Abstract

Identification and fine mapping of quantitative trait loci (QTLs) for grain yield and its related traits in maize are very important for molecular breeding by design. In the past few decades, a wealth of QTLs mapping data for grain yield and its related traits in maize has been produced using molecular marker approaches. In order to unlock the full potential of the information contained in these independent experiments, four hundreds QTLs for grain yield and its related traits in maize, collected from different publications, were used to construct new QTL integrated map and consensus map using bioinformatics and meta-analysis methods with IBM2 2008 neighbors as reference. It showed that these QTLs were distributed on all 10 chromosomes unevenly, with the most on chromosome 1 and the least on chromosome 10. QTLs for ear length, cob diameter, kernel number per row, kernel weight, and grain yield were mainly distributed on chromosome 1, while QTLs for ear row number on chromosome 9. Ninety-six "Consensus" QTLs for grain yield and its related traits were estimated, including 43 "Consensus" QTLs for kernel weight, 32 "Consensus" QTLs for grain yield, and 8, 5, 4, 3, 1 "Consensus" QTLs for ear diameter, ear row number, cob diameter, kernel number per row, ear length, respectively. QTLs with similar phenotype were clustered on the same or nearby locations. These results provide a good basis for studying genetic mechanism and molecular marker-assisted selection for grain yield and its related traits in maize.