Relations of Races and Virulences of Puccinia recondita f. sp. tritici to Wheat Cultivars and Areas. J. F. Schafer, Research Plant Pathologist, Cereal Rust Laboratory, USDA-ARS, Department of Plant Pathology, University of Minnesota, St. Paul 55108. D. L. Long, Plant Pathologist, Cereal Rust Laboratory, USDA-ARS, Department of Plant Pathology, University of Minnesota, St. Paul 55108.. Plant Dis. 72:25-27. Accepted for publication 23 September 1987. This article is in the public domain and not copyrightable. It may be freely reprinted with customary crediting of the source. The American Phytopathological Society, 1988. DOI: 10.1094/PD-72-0025.

Comparisons of the isolates of Puccinia recondita f. sp. tritici obtained in 1986 by means of source cultivar, UN race, virulence phenotype, specific virulence character, and source area and state showed seven relationship patterns. Several populations of UN 14 were closely associated with the northeastern United States and with the eastern white winter wheat cultivars. UN 14 (p 1,2c,10,11,18) showed a special affinity for Coker 983. UN 2 (p 3,11) showed a special affinity for derivatives of Purdue 4946. Virulence to Lr1 was required to parasitize Tyler. Virulences to Lr24 and 26 were associated with, but not limited to, cultivars known to possess those resistance genes. Combined virulence to Lr1 and 16 was associated with ProBrand 812. Combined virulence to Lr2a and 9 was associated with Coker 762 and Coker 93-23.

Keyword(s): host-parasite/cultivar-race (virulence) relations, wheat leaf rust.