THE USDA QUINCE AND PEAR GENEBANK IN OREGON, A WORLD SOURCE OF FIRE BLIGHT RESISTANCE

The U.S. Department of Agriculture (USDA), Agricultural Research Service (ARS), has operated a genebank for temperate fruit and nut crops in Corvallis, Oregon since 1981. This facility, the National Clonal Germplasm Repository (NCGR), is devoted to conservation of many rosaceous species that are potential hosts for fire blight (Erwinia amylovora (Burrill) Winslow). Globally diverse collections of Amelanchier, Cydonia, Mespilus, Pyrus and Sorbus germplasm have been assembled at the Corvallis genebank. Unique genotypes are maintained as growing plants, evaluated for phenotypic and genotypic traits, tested for virus contamination, documented in a national public germplasm database and freely distributed to international researchers. Seed collections represent wild species populations. The NCGR Cydonia collection includes more than 100 clones and 14 seedlots from 15 countries. Fire blight resistance has not been documented in the Cydonia germplasm; however, many recent introductions from the quince center of origin in central Asia and the trans-Caucasus region have yet to be evaluated. The NCGR Pyrus collection includes 2030 clonal pear accessions and 327 seedlots representing 36 Pyrus taxa from 53 countries. More than 160 pear clones are identified as being highly to moderately resistant to fire blight. Temperatures in western Oregon’s Willamette Valley are normally below the threshold necessary for spread of fire blight during Cydonia and Pyrus bloom periods, and the weather is dry in the summer, making NCGR-Corvallis an ideal location to preserve these living germplasm collections for future generations.