Open AccessVirulence of Puccinia triticina on Wheat in the United States from 1996 to 1998
Author(s) -
Don M. Long,
K. J. Leonard,
M. E. Hughes
Publication year - 2000
Publication title -
plant disease
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.663
H-Index - 108
eISSN - 1943-7692
pISSN - 0191-2917
DOI - 10.1094/pdis.2000.84.12.1334
Subject(s) - biology , overwintering , wheat leaf rust , virulence , race (biology) , host (biology) , phenotype , rust (programming language) , botany , genetics , gene , computer science , programming language
Isolates of Puccinia triticina were obtained from wheat leaf collections made by cooperators throughout the United States and from surveys of wheat fields and nurseries in the Great Plains, Ohio Valley, and Gulf Coast states in 1996, 1997, and 1998. Virulence-avirulence phenotypes were determined on 14 host lines that are near-isogenic for leaf rust resistance. We found 31 phenotypes among 277 single uredinial isolates in 1996, 56 phenotypes among 989 isolates in 1997, and 43 phenotypes among 989 isolates in 1998. As in previous surveys, regional race distribution patterns showed that the central United States is a single epidemiological unit distinct from the eastern United States. The distinctive racial composition of collections from the southeast, northeast, and Ohio Valley indicate that populations of P. triticina in those areas are not closely connected, suggesting that epidemics originate from localized overwintering sources.