Full Length Research Paper

QTL analysis of kernel soluble sugar content in super-sweet corn

Xin Qi^{1, 2}, Yingjun Zhao¹, Lili Jiang², Yue Cui¹, Yulan Wang¹ and Bao Liu²*

¹College of Agronomy, Jilin Agricultural University, Changchun, Jilin 130118, China.

²Key Laboratory of Molecular Epigenetic of MOE, Northeast Normal University, Changchun, Jilin 130024, China.

*Corresponding author. E-mail: baoliu6677@nenu.edu.cn. Tel: 86-431-85099822. Fax: 86-431-85099822.

Accepted 6 November, 2009

   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.

Key words: Super-sweet corn, genetic map, SSR, QTLs, kernel soluble sugar content.