Phenotypic Diversity in Two Populations ofPuccinia reconditaf. sp.triticiin Canada During 1931-1987

The Canadian eastern and prairie populations of Puccinia recondita f. sp. tritici from race surveys conducted during 1931-1987 were assessed for phenotypic diversity within each population and phenotypic overlap between the two populations using four different indexes based on infection type on the modified Unified Numeration differentials. The indexes showed that the two populations had similar levels of absolute diversity during 1931-1959. Diversity in the prairie population was consistently lower than in the eastern population during 1960-1975, increased during 1976-1984, and decreased during 1985-1987 (...)