Genomics to Improve Alfalfa as a Biofuel Feedstock.

Alfalfa, most commonly used as highly nutritious forage, also has potential as a biofuel crop. As a biofuel, leaves would be separated from stems and used as high protein feed, while stems would be used for biopower or for cellulosic ethanol production. Optimization of alfalfa for a biofuel requires both improving yield and modifying stem cell wall composition for the desired use. We are developing high-throughput genetic markers for alfalfa to facilitate marker-assisted selection and genome-wide selection. In addition to tetraploid alfalfa breeding populations, we are also evaluating diploid alfalfa germplasm as a source of desirable alleles unexplored by conventional breeding. As a consequence of this research, we will also understand the population structure of diploid alfalfa germplasm and a tetraploid breeding population, elucidate the extent of linkage disequilibrium in the alfalfa genome, identify SNP in cell-wall synthesis candidate genes, and conduct association analyses in multiple populations. Results of this project will provide additional methods of improving alfalfa as a biofeedstock.