Location: Cereal Disease Laboratory
Title: Leaf rust of wheat: Pathogen biology, variation and host resistance Author
Submitted to: Forests
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: January 11, 2013
Publication Date: January 16, 2013
Citation: Kolmer, J.A. 2013. Leaf rust of wheat: Pathogen biology, variation and host resistance. Forests. 4:70-80. Interpretive Summary: Wheat is attacked by the rust fungus called Puccinia triticina, which causes the disease leaf rust. The wheat leaf rust fungus is genetically diverse with many forms that differ for molecular markers and for ability to attack different resistance genes in wheat. This article briefly summarizes current information on genetic variation in Puccinia triticina; leaf rust resistance genes in wheat, and methods for testing wheat breeding lines for rust resistance. This information be used by plant pathologists and plant breeders in developing rust resistant cereal cultivars.
Technical Abstract: Rusts are important pathogens of angiosperms and gymnosperms. Rust fungi are among the most important pathogens of cereals. Cereal rusts are heteroecious and macrocyclic requiring two taxonomically unrelated hosts to complete a five spore stage life cycle. Cereal rust fungi are highly variable for virulence and molecular polymorphism. Wheat leaf rust, caused by Puccinia triticina is the most common rust of wheat on a world wide basis. Many different races of P. triticina that vary for virulence to leaf rust resistance genes in wheat differential lines are found annually in the US. Molecular markers have been used characterize rust populations in the US and worldwide. Highly virulent races of P. triticina are selected by leaf rust resistance genes in the soft red winter wheat, hard red winter wheat and hard red spring wheat cultivars that are grown in different regions of the US. Cultivars that only have race-specific leaf rust resistance genes that are effective in seedling plants lose their effective resistance and become susceptible within a few years of release. Cultivars with combinations of race non-specific resistance genes have remained resistant over a period of years even though races of the leaf rust population have changed constantly.