Submitted to: Forage Focus
Publication Type: Trade Journal
Publication Acceptance Date: November 25, 2009
Publication Date: December 1, 2009
Citation: Gronwald, J.W. 2009. Using Gene Arrays as Tools to Develop Alfalfa as a Biomass Crop. Forage Focus. December issue. p. 11 and 14. Technical Abstract: Alfalfa has considerable potential as a biomass feedstock for producing cellulosic ethanol. The model that we propose for alfalfa as a biomass crop involves stripping leaves from stems. The leaves would be used as a protein supplement for livestock while the stems would be used for cellulosic ethanol production. Scientists at the USDA-ARS Plant Science Research Unit have developed a large-stemmed, non-lodging, biomass-type alfalfa experimental germplasm and a biomass production system. When the biomass-type alfalfa is managed using the biomass production system, the biomass produced is increased by 40% and the theoretical ethanol yield is doubled compared to hay-type alfalfa grown under a hay production system. An important next step in advancing alfalfa as a biomass crop for cellulosic ethanol production is increasing cellulose and decreasing lignin in stem cell walls. Alfalfa stems that have more cellulose and less lignin in their cell walls will yield more ethanol. To identify key genes that regulate cellulose and lignin levels in alfalfa stems, we used gene arrays to compare gene expression in two alfalfa clonal lines that differ in cellulose and lignin concentrations in stem cell walls. Several key genes were identified that can be developed as markers in a breeding program to select cultivars with high cellulose and low lignin in stems.