Dissecting quantitative trait variation—examples from the tomato

Quantitative variation is prevalent in nature and in plant breeding. However, it wasn’t until the past two decades that it became technically feasible to begin probing the individual loci and genetic causes of natural, quantitative trait variation. Understanding the basis of quantitative variation is key not only to understanding evolution, but also in developing new insights and methodologies to improve traits such as yield, resistance to abiotic stress, and nutritional quality. In plants, tomato was one of the first species in which significant inroads were made into understanding the genetic and molecular bases of quantitative trait variation. Summarized herein are some of the lessons learned from tomato with regards to quantitative trait variation.