Expansion of the USDA Switchgrass Germplasm Collection.

Increased interest in switchgrass, Panicum virgatum, as a cellulosic biofuel source has created a demand on the USDA National Plant Germplasm System to provide a more diverse and representative set of germplasm for this species.  In response to this increased demand, the NPGS has sought ways to expand the collection through collection efforts and donations.  Dating back to as recent as 2004, the switchgrass collection contained as few as 38 available accessions collected from a limited geographic range.  In 2003, 131 unavailable accessions maintained as back up at NGCRP in Fort Collins, CO were incorporated into the working collection located at the Plant Genetic Resources Conservation Unit in Griffin, GA.  The majority of these accessions, donated by Arvid Boe, were collected in the South Dakota area in the early 70s.  In 2008, Dr. Paul Salon with the Natural Resources Conservation Service donated 83 accessions collected predominately from New York and surrounding states.  Collections trips to Florida in 2008 and 2009 by the authors in collaboration with Dr. M.J. Williams and Mary Anne Gonter (NRCS) provided an additional 60 accessions.  Regeneration of this germplasm is ongoing, and the germplasm will be made available for distribution as seed increases are completed.  These combined efforts have expanded the collection to 322 accessions, an almost ten fold increase, and have greatly increased the diversity of the germplasm.