Quantitative trait locus (QTL) mapping for 100-kernel weight of maize (<i>Zea mays</i> L.) under different nitrogen regimes

Abstract

100-kernel weight (KW) is one of the most important agronomic traits in maize (Zea mays L.), related to yield. To realize its genetic basis, in this study, a recombinant inbred line (RIL) population derived from the cross between Mo17 and Huangzao4 was used for quantitative trait locus (QTL) mapping for KW under high and low nitrogen (N) regimes. As a result, five QTLs were identified on chromosomes 3, 4, 7 and 9, of which three were detected under both N environments, while the other two QTLs were respectively detected under high and low N regimes. These QTLs could explain phenotypic variance rom 4.47 to 14.47%. Due to additive effects, the three QTLs from Mo17, including two on chromosome 3 and one on chromosome 4, could increase KW from 0.64 to 1.01 g, while the other two from Huangzao4 on chromosomes 7 and 9 could decrease KW from 0.62 to 1.07 g. These results are beneficial for understanding the genetic basis of KW and developing the markers linked with KW for marker-assisted selection breeding in maize.

Key words: Maize (Zea mays L.), 100-kernel weight, quantitative trait locus (QTL), recombinant inbred line (RIL), nitrogen regime.