QTL x Environment Interactions and Latitudinal Adaptation in Switchgrass (Panicum virgatum)

Switchgrass (Panicum virgatum) is a polyploid C4 perennial grass that is native to North America and has been championed as a promising biofuel feedstock. It is a common member of most native prairie communities and exhibits extensive phenotypic variability and adaptation across its range, especially related to latitude and precipitation gradients. Much of this variability is associated with evolved lowland and upland ecotypes. Upland ecotypes are short, rhizomatous, thin-stemmed, and generally adapted to drier conditions while lowland ecotypes are vigorous, tall, thick-stemmed and adapted to more mesic sites. Here, we report on progress on the development of genetic and genomic resources for switchgrass, as well as present results from field experiments aimed at understanding upland/lowland ecotype divergence and local adaptation. In particular, we present preliminary results from QTL studies aimed at detecting gene-by-environment interactions for performance utilizing collaborative common garden experiments across the species latitudinal range.