Sunday, April 29, 2007 - 3:35 PM

Sorghum biomass/feedstock genomics research for bioenergy

William L. Rooney1, John Mullet2, Stephen Kresovich3, Doreen Ware4, and Patricia Klein2. (1) Department of Soil & Crop Science, Texas A&M University, 2474 TAMU, College Station, TX 77843-2474, (2) Institute for Plant Genomics and Biotechnology, Texas A&M University, 2474 TAMU, College Station, TX 77843-2474, (3) Institute for Genomic Diversity, Cornell University, 158 Biotechnology Building, Ithaca, NY 14853-2703, (4) Cold Spring Harbor Laboratory, Freeman Bldg., 1 Bungtown Rd., Cold Spring Harbor, NY 11724

Sorghum has the potential to be one of the species dedicated to biomass production because of its high productivity, drought tolerance, established production systems, and genetic diversity. The purpose of our research is to produce sorghum genotypes for use in bioenergy production. Our specific objectives are to: (1) annotate genes, pathways and regulatory networks identified in the sorghum genome that are important for biomass generation, and (2) identify, map and clarify the function of trait loci that modulate accumulation and quality of biomass in sorghum. Our approach is to identify genes encoding proteins involved in biochemical pathways important for biomass generation and composition related to biofuel production (starch, lignin, sugar, (hemi)cellulose), and project them onto biochemical pathways using the database MetaCyc. For objective 2 we are measuring grain, biomass, and carbohydrate yields in a population consisting of 175 recombinant inbred lines (RILs) from the cross of BTx623 (a high-yielding early flowering grain sorghum) × Rio (a high-biomass sweet sorghum). Plant growth parameters (plant height, flowering time and tillering) will be analyzed, along with traits that likely modulate carbohydrate partitioning in various tissues. Traits that affect grain yield, biomass yield, composition of structural and non-structural carbohydrates, and overall energy gain will also be evaluated. In parallel, a RIL population will be developed by crossing tall, photoperiod sensitive late flowering genotypes that vary in biomass accumulation to explore the genetic basis of biomass accumulation and composition. The population will be analyzed for variation in growth characteristics, lodging, biomass yield and composition.