Genetic analysis of QTLs for lysine content in four maize DH populations

Abstract

Background Low level of lysine in maize endosperm is considered to be a major problem for determining the nutritional quality of food and feed. Improving the lysine content is favorable to improve maize quality by optimizing feeding requirement. Understanding the genetic basis of lysine content benefits greatly improving maize yield and optimizing end-use quality. Results Four double haploid (DH) populations were generated and used to identify quantitative trait loci (QTL) associated with lysine content. The broad-sense heritability indicated the majority of lysine content variations were largely controlled by genetic factors. A total of 12 QTLs were identified in a range of 4.42–12.66% in term of phenotypic variation explained (PVE) which suggested that a large number of minor-effect QTLs mainly contributed to the genetic component of lysine content. Five well-known genes encoding key enzymes in maize lysine biosynthesis pathways locate within QTLs identified in this study. Conclusions The information presented will pave a path to explore candidate genes regulating lysine biosynthesis pathways and be useful for marker-assisted selection and gene pyramiding in high-lysine maize breeding programs.