Monitoring of Virulence Factors of Puccinia triticina Eriksson, the Causal Agent of Wheat Leaf Rust in Iran During 2002-2004

Leaf (brown) rust, caused in wheat by the fungus Puccinia triticina is an important disease in north, west and south of Iran. Leaf rust is an endemic disease in Iran, which apperas in many parts of the country annually. Use of resistant cultivar is the best way to control this disease. To find resistant sources to the pathogen and use in the breeding program, it is necessary to determine virulence factors of the pathogen. In the present study, 12 locations were allocated in different parts of Iran to study virulence factors of the pathogen in trap nurseries with 37 leaf rust near isogeneic lines and a susceptible cultivar Bolani. Each line was sown in two rows of 1 meter length. The nurseries were maintained under natural infection of the pathogen. Reaction of each line was recorded at the time when infection on the susceptible control was at the maximum level, and presence of virulence for different resistance genes was determind. Results indicated presence of virulence for genes Lr1, Lr2b, Lr2c, Lr3, Lr3ka, Lr3bg, Lr10, Lr11, Lr12, Lr13, Lr14a, Lr14b, Lr15, Lr16, Lr17, Lr20, Lr21, Lr22a, Lr22b, Lr23, Lr24, Lr26, Lr30, Lr32, Lr33 and Lrb. No virulence was detected for Lr9, Lr18, Lr19, Lr25, Lr28, Lr29, Lr34, Lr35, Lr36 and Lr37 genes. Use of these genes with combination of adult plant resistance genes is expectd to be a useful method to control of leaf rust disease.