QTL mapping for ear length and ear diameter under different nitrogen regimes in maize

Ear length (EL) and ear diameter (ED) are two of the most important traits in maize (Zea mays L.), related to yield and plant morphology. In this study, an F9 recombinant inbred line (RIL) population was used to identify the quantitative trait loci (QTLs) controlling EL and ED under two nitrogen (N) regimes. As a result, 3 QTLs were detected under N rich environment, 1 for EL on chromosome 1 and 2 for ED on chromosome 9. Under N stress environment, 4 QTLs were identified, 1 for EL on chromosome 1 and 3 for ED on chromosome 4 and 9. The phenotypic variances explained by these QTLs ranged from 5.68% to 9.86%, their additive effects were from -0.74 to 0.16. These results were beneficial for realizing the genetic basis of EL and ED and carrying out marker-assisted selection in maize.