A geometric morphometrics-based mapping model of leaf shape evolution

Understanding how leaf shape diversifies and evolves requires the genetic information that encodes morphological variation within and between species. Genetic mapping provides a uniqueway for the dissection of leaf shape into its underlying Mendelian genes, known as quantitative trait loci (QTLs), but this approach relies on how leaf shape is quantified. In this chapter, we describe a computational approach that integrates geometric morphometrics (GM)-based shape analysis and principal component analysis (PCA) into the statistical framework of genetic mapping. This approach can map how QTLs affect both global and detailed variation of leaf shape. We demonstrate its utility by applying it to the genetic mapping study of a woody plant-mei (Prunus mume Sieb. et Zucc). This approach could serve as a powerful tool to understand the genetic basis underlying the natural variation and evolution of leaf shape in plants.