Adaptations between ecotypes and along environmental gradients in Panicum virgatum

Determining the patterns and mechanisms of natural selection in the wild is of fundamental importance to understanding the differentiation of populations and the evolution of new species. However, it is often unknown the extent to which adaptive genetic variation is distributed among ecotypes between distinct habitats versus along large-scale geographic environmental gradients, such as those that track latitude. Classic selection in the wild experiments in switchgrass, Panicum virgatum, tested for adaptation at both of these levels of natural variation. Here we review what these field experiments, as well as modern agronomic field trials, have taught us about natural variation and selection at both the ecotype and environmental gradient level in P. virgatum. With the recent genome sequencing efforts of P. virgatum, it is poised to become an excellent system for understanding the adaptation of grassland species across the eastern half of North America. The identification of genetic loci ...