Mapping of QTL traits in corn using a RIL population derived from a cross of dent corn × waxy corn

Abstract

In this study, 80 F7:8 recombinant inbred lines, derived from a cross between dent corn and waxy corn, were evaluated for ten grain yield and kernel quality-related traits over a 2-year period. A total of 39 quantitative trait loci (QTLs) and 74 epistatic interactions were confirmed in 2011 and 2012. All QTLs detected in 2011 showed greater than 10 % phenotypic variation (10.21–50.3 %). In 2012, 19 of 23 QTLs showed phenotypic variation greater than 10 % (6.46–93.71 %). Among all QTLs detected, qAC9 had the highest phenotypic variance (93.71 %). Additionally, qEH4, qSEL6, and q100KW10 were stably expressed. These QTLs had higher phenotypic variance and were observed in both years; therefore, they may be considered major QTLs. Some new QTLs identified in this study were located on different loci compared with other studies. The genetic region (bin 4.08) strongly controls plant height and ear height, and results from pleiotropy and/or tight linkage. qST3 and qEH3 were co-located within two common adjacent simple sequence repeat (SSR) markers (umc2275 and umc1273), whereas qEL6 and qSEL6 were co-located within two common adjacent SSR markers (umc2309 and bnlg238). The QTLs related to kernel quality traits, qWC4 (water content) was tightly linked to the gene bt2 (brittle endosperm 2) and qAC9 (amylose content) located between the flanking markers umc1634 and wx1 (waxy1). Thus, these SSR markers are a useful selection tool for screening grain yield and yield component traits.