Start Date: Dec 01, 2009
End Date: Aug 31, 2013
Five different strains of switchgrass plants that differ in their cold-hardiness and fitness parameters will be planted in the fields. Crowns and rhizomes will be harvested from these plants at specific times over two growing seasons for genetic (High-throughput pyrosequencing; 454 transcriptomics) and metabolite analyses. Additional plants will be subjected to isotope-tracer experiments using stable isotopes for carbon (C-13) and nitrogen (N-15) to query nutrient recycling over two growing seasons as affected by the genetic background of the plants. These data will permit improved insights in the molecular and physiological events that impact perenniality and fitness in switchgrass. Obj. 2. Using genomic approaches (454 pyrosequencing and bioinformatics), we will discover additional genes impacting fitness using individual plants from switchgrass populations divergently selected over ~30 years for ruminant digestibility. These plants are a unique genetic resource unavailable elsewhere, and show improved conversion to ethanol and decreased winter survival. Obj. 3. We will attempt to uncover marker-trait associations that can be used to reduce the generations, and within generation time and expense of phenotyping in the breeding process by use of marker assisted selection (based on genes uncovered in Obj.1 and Obj. 2). Over 2000 plants from various genetic backgrounds have been planted in the field for these analyses.