Panicum hallii as a diploid switchgrass model:
The agronomic development of switchgrass as a biofuel crop has focused primarily on Panicum virgatum. Unfortunately, P. virgatum is a complex polyploid (both tetraploid and octaploid series exist), has a large genome (1C > 1500 Mbp) and is thus not easily amenable to traditional molecular genetic studies. In contrast, the closely related diploid species Panicum hallii has a much simpler genome (~500 Mbp) and can provide a genetic reference to support and interpret parallel studies in P. virgatum. Importantly, P. hallii occurs over the same moisture gradient as P. virgatum in the southern Great Plains and has locally adapted mesic (var. filipes) and xeric (var. hallii) ecotypes.
We are currently developing P. hallii as a model genomic system through high-throughput genomic and transcriptome sequencing. Our goal is to understand the genetic basis of natural variation in drought tolerance and biofuel related traits through a combination of high-density genetic mapping with RNA-sequencing. This aim will be achieved by leveraging distribution of natural drought adaptations distributed along the steep cline in soil moisture across Texas and the desert Southwest.