Climate change is the single greatest threat to ecosystem function, human heath and the global economy. One strategy for mitigating this stress is the development of alternative renewable energy sources. The utilization of perennial feedstocks, including switchgrass (Panicum virgatum), shows strong potential for minimizing greenhouse gas emissions while minimizing the damage to ecosystems and threats to global food security associated with corn-based ethanol production.
Switchgrass is a C4 grass species spanning a continuous range from Canada to Mexico in the Midwestern United States. Adaptation to climate and growing season across this range has led to a divergence into two ecotypes, the upland ecotype in the north is resource acquisitive and fast growing, the lowland ecotype in the south is conservative and slow growing but relatively more stress tolerant. As the morphological variance between these ecotypes was driven by natural evolutionary processes, rather than anthropogenic domestication, Switchgrass serves as an ideal model organisms for testing evolutionary questions as well as improving biofuel capacity.
The Juenger lab at UT Austin has initiated the switchgrass collaborative towards better understanding of genetic drivers of switchgrass yield and stress tolerance in order to inform breeding strategies in line with biofuel production goals. This collaborative has developed powerful tools for understanding the links between structural and functional intraspecific variance. In a QTL mapping population bred from two upland and two lowland ecotype grandparents, physiologically important traits have been recombined to form a novel genetic and phenotypic landscape. I am currently utilizing genetic and genomic tools to approach causal drivers of the complex feedback between plant anatomy and physiology, specifically focusing on genetic variation in leaf anatomy and its implications for the leaf economics spectrum.

P. virgatum stomata Preparing anatomical samples Penny helps in the field switchgrass ecotypes Joe Edwards during 2018 sampling campaign Switchgrass massacre micro ct of switchgrass tiller P. virgatum tiller cross section