Genetic loci mapping associated with maize kernel number per ear based on a recombinant inbred line population grown under different nitrogen regimes

Abstract

ABSTRACT. Kernel number per ear (KNE) is one of the most important yield-related agronomic traits in maize (Zea mays). To clarify its genetic basis, we made a quantitative trait locus (QTL) analysis of KNE in a recombinant inbred line population derived from lines Mo17 and Huangzao4, under two nitrogen (N) regimes. Seven QTLs, on chromosomes 4, 6 and 9, were mapped under the high N regime, which explained phenotypic variation ranging from 5.03 to 15.49%. Under the low N regime, three QTLs were located on chromosomes 6 and 9, which accounted for phenotypic variation ranging from 8.54 to 12.21%. These QTLs had different mapping intervals to their nearest markers, ranging from 0 to 16.5 cM. According to the chromosome positions and genetic effects of these QTLs, only seven QTLs for KNE were identified in our experiment, out of which three were found under both N regimes, on chromosomes 6 (one) and 9 (two); the other four were mapped only under the high N regime, on chromosomes 4 (three) and 6 (one). This information could be useful for developing marker-assisted selection in maize-breeding projects.

Identification of QTL for resistance to Mediterranean corn borer in a maize tropical line to improve temperate germplasm

“…The QTL located in chromosome 6 is especially interesting because it explained a high proportion of the genetic variance (17 %) with the lowest estimation bias for this parameter and with a high detection frequency (95 %) through CV runs. Although no QTL for yield under infestation with corn borers have been previously found in this region (bin 6.01- 6.02) several studies have reported important QTL for grain yield and its components in physiological conditions in the same region in other mapping populations [ 34 – 38 ]. Even the results of a fine mapping study suggest that a pleiotropic locus could be affecting grain yield and related traits in this region of chromosome 6 [ 39 ].…”

Fine Mapping and Candidate Gene Prediction of a Pleiotropic Quantitative Trait Locus for Yield-Related Trait in Zea mays

“…Moreover, many QTLs for GY-related traits were identified on 6S of the maize chromosome by multiple groups, such as a QTL for ear length (EL) in phi126-bnlg1371 [20], bnlg1538-bnlg391 [21] and phi126-npi235 [1]. Liu et al (2011) identified a QTL for KNPR around phi031 in Y1-umc1257 (6.01–6.02bin) [22], and Tan et al (2011) identified a QTL for kernel weight in umc1656-umc1796 (6.02–6.04bin) [23]. Our group identified a chromosome segment around gpc2 harboring a QTL for KNPR across four environments, designated as qKNPR6 [24].…”