Founding clones, major contributing ancestors, and exotic progenitors of prominent North American potato cultivars

Neither founding clones nor major genetic contributors to modern North American potato cultivars have been systematically identified. Available pedigrees, through 12 generations, were used to identify founding clones and major contributing ancestors (MCAs), to outline relationships among these clones, to determine the genetic contribution of MCAs and exotic germplasm to prominent cultivars, and to draw conclusions about the gene base of prominent North American cultivars. Based on 1996 certified seed acreage, 46 cultivars were identified as prominent, of which 44 had published pedigrees. Using this pedigree data, 12 MCAs consisting of four types were identified: land race types including Daber and Sutton’s Flourball; immediate descendants of land race types including Busola, Early Rose, Garnet Chili, Imperator, Richter’s Jubel, and Triumph; early USDA releases including Chippewa, Earlaine, and Katahdin; and one derivative of a GermanSolanum demissum ×S. tuberosum population designated Germ. No. 3895-13. These clones appeared in the pedigrees of from 61 to 100% of the 44 most prominent North American cultivars. Some MCAs appeared numerous times in the pedigrees of the cultivars with the maximum being Busola, which appeared in the pedigree of NorDonna 94 times. Across the 44 cultivars, the genetic contribution of MCAs averaged from 1.4% for Daber to 23.2% for Katahdin. A positive genetic contribution by exotic germplasm was present in 34 of the 44 cultivars. Krantz, Russet Nugget, Conestoga, and Yukon Gold had exotic germplasm contributions of 49.5, 34.1, 32.3, and 31.3%, respectively.