Fernando F. Castro-Álvarez, Manilal William, David J. Bergvinson, Silverio García-Lara

Theoretical and Applied Genetics; March 2015, Volume 128, Issue 3, pp 411-419

http://link.springer.com/article/10.1007/s00122-014-2440-6

Abstract

Key message  A tropical RIL maize population was subjected to phenotypic and genotypic analysis for maize weevil resistance during four seasons, and three main genomic areas were detected as main QTLs. Abstract  The maize weevil (Sitophilus zeamais) (MW) is a common and important pest of stored maize (Zea mays) worldwide, especially in tropical areas. Quantitative trait loci (QTLs) associated with the MW have been analyzed previously in an F2 maize population. In this work, new germplasm-based F6 recombinant inbred line (RIL) fami-lies, derived from the cross of Population 84 and Kilima, were analyzed using insect bioassays during four seasons. The parameters analyzed for MW resistance were grain weight losses (GWL), adult progeny (AP), and flour pro-duction (FP). Composite interval mapping identified a total of 15 QTLs for MW parameters located on six chro-mosomes, explaining between 14 and 51 % of phenotypic

variation (σ_p²) and 27 and 81  % of genotypic variation (σ_g²). The QTL obtained for GWL was located in bin 2.05, which explained 15 % of σp². For AP and FP, the QTLs were located on regions 1.09 and 2.05, explaining 7 and 15 % of σp², respectively. Comparative analysis between F2 and F6 families showed similarities in QTL localization; three main regions were co-localized in chromosomes 4.08, 10.04, and 10.07, where no resistance-associated genes have been reported previously. These regions could be used for a marker-assisted selection in breeding programs for MW resistance in tropical maize.

Fig. 1  Combined SSR linkage map based on 100 F6 families from the cross P84 ×Kilima. Approximate QTL positions for grain weight loss (GWL), Flour production (FP), and adult progeny (AP) of maize weevil Sitophilus zeamais are shown. Shaded (Kilima)/non-shaded (P84) shapesindicates the parent from which the favorable allele was derived. QTL with a significant QTL ×E interaction are indicating with italics