Submitted to: Phytopathology
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: April 1, 2006
Publication Date: April 1, 2006
Citation: Ordonez, M.E., Kolmer, J.A. 2006. Virulence and molecular characterization of a world-wide collection of Puccinia triticina from durum wheat compared to U.S. bread wheat races. Phytopathology. 96:587. Technical Abstract: Leaf rust caused by Puccinia triticina, has recently become more prevalent on durum wheat in Europe, North and South America. We determined the virulence specificities of P. triticina isolates from durum wheat from Argentina, Chile, Ethiopia, France, Mexico, Spain and the USA, and 10 representative races of P. triticina from bread wheat from the USA, on 35 differential lines of Thatcher wheat. Genetic diversity of these populations was also determined with 11 simple sequence repeat (SSR) markers. Populations of leaf rust from durum were avirulent to many Lr genes, but had high infection types on 11 resistance genes, which are mostly derived from AABB wheats. Some isolates from durum wheat in Ethiopia were avirulent to Thatcher and all differential lines tested. Population analysis from the SSR data showed that populations from durum wheat from South America, North America and Europe were closely related for SSR genotypes, suggesting a recent trans-continental migration of these isolates from a common source while populations from Ethiopia, and bread wheat had distinct genotypes, suggesting different origins.