Combining Three Mapping Strategies to Reveal Quantitative Trait Loci and Candidate Genes for Maize Ear Length.

Ear length (EL) is an important trait in maize (Zea mays L.) because it is positively correlated with grain yield. To understand the genetic basis of natural EL variation, a F-2:3, a four-way cross and a genome-wide association study (GWAS) population were used to identify the quantitative trait loci (QTLs) and candidate EL genes. Linkage mapping identified 14 QTLs in two types of populations from multiple environments. Six of them were located in three common genomic regions considered "stable QTLs". Candidate genes for the three stable QTLs were identified by the GWAS results. These were related to auxin transport, cell proliferation, and developmental regulation. These results confirm that maize EL is under strong genetic control by many small-effect genes. They also improve our understanding of the genetic basis of maize EL.