QTL analysis of kernel soluble sugar content in supersweet corn

Abstract

A genetic linkage map was constructed with SSR markers based on a super-sweet corn population consisting of 208 F2 individuals from the cross Ji557 (sh2) × Ji165 (sh2). Density of the linkage groups varied from 2.2 cM to 65.3 cM, with an average of 13.0 2 cM between two adjacent markers. The map covered 1470.9 cM of the total recombination length of the super-sweet corn. Using Mapmaker/QTL, 11 quantitative trait loci (QTLs) were identified for kernel soluble sugar content, explaining 3.5 - 20.3% of soluble sugar content variance and collectively accounting for 63.7% of the trait variance. Of the 11
QTLs associated with kernel soluble sugar content, 2 (18.2%) showed additive effects, 3 (27.3%) showed partially dominant effects, 3 (27.3%) showed dominant effects and 3 (27.3%) showed over-dominant effects. All four types of genetic effects appeared to play important roles in determining the kernel
soluble sugar content in super-sweet corn cultivars.