Metabolomics and Plant Quantitative Trait Locus Analysis – The optimum genetical genomics platform?

Biologists have long strived to understand what causes phenotypic differences between two individuals. This includes differences in morphology, disease susceptibility, physiology as well as potential metabolic differences underlying these higher order phenotypes. The diversity between individuals is partitioned into both environmental and genetic variation. Most genetic variation studied to date tends to be qualitative such that there are one or more distinct and non-overlapping phenotypic states. However, most phenotypic differences are quantitative such that there are numerous overlapping phenotypic states [1-4]. It has been known for nearly a century that the approximate genetic position of loci controlling these quantitative traits can be identified through associating marker and phenotype variation in a structured population [5]. This association is the foundation for Quantitative Trait Locus (QTL) mapping experiments that attempt to identify the number, phenotypic impact and interaction of loci controlling a quantitative trait.