Poster Abstract

Leaf (brown) rust induced by Puccinia triticina is a common wheat disease causing serious yield losses around the world. Breeding for genetic resistance is the most economic way of avoiding yield losses. Therefore, wheat breeding programs in many countries apply resistance breeding in their programs for resistance, especially a long lasting one, against leaf rust. The most preferred long-lasting resistance type is slow rusting on these days. Slow rusting acquires both prediction of Lr genes of genotypes in the greenhouse and an efficient screening of leaf rust under field epidemy. Here, we studied Lr genes of winter-facultative wheat genotypes improved by the International Winter Improvement Program (IWWIP) besides 40 Thatcher leaf rust isolines. Greenhouse and field studies were in CIMMYT (Mexico) headquarters in 2005. The genotypes were inoculated with twelve common leaf rust races in the greenhouse. The Lr genes identified in the genotypes and number of varieties with the genes, either in combination or alone were the following: Lr1 (in 8 genotypes), Lr3a (7), Lr10 (17), Lr13 (12), Lr14a (7), Lr10 (1), Lr16 (7), Lr17 (8), Lr23 (12), Lr24 (6), and Lr26 (3), Lr27(2), Lr31 (2). All genotypes were also inoculated with leaf rust spores in the field and then screened using modified Cobb scale every succeeding week. Based on the screenings, the Area Under The Disease Progress Curve (AUDPC) was later calculated separately for each genotype. The variation for AUDPC and a clear indication of slow rusting in winter wheat genotypes adequately existed.

Global Wheat Program

Text in English

CBAK01|INT1787|INT0610

CIMMYT Staff Publications Collection