Poster Abstract

Rust diseases, especially leaf rust caused by Puccinia triticina, are globally important fungal pathogens of wheat and may cause significant yield losses of up to 40% or more, worldwide. Due to rapid changes in pathogen races, single gene resistances are generally short lived when deployed in wheat cultivars. A more durable form of resistance, known as slow leaf rusting, has been identied and characterized in some genotypes. Genetic studies indicate that slow rusting resistance is under polygenic control with moderate to high heritability. Such resistance, also known as adult plant resistance (APR), is controlled by minor genes. Although 10-12 slow rusting genes are present in CIMMYT spring wheats, only two such genes, Lr34 and Lr46, have been characterized. Fifteen wheat genotypes, including twelve CIMMYT lines, two elite Indian wheat cultivars, HUW 234 and HUW 468, and one known leaf rust susceptible cultivar, Agra Local, were included in the present study. These lines were firstly evaluated under field conditions for disease severity, latent period and incubation period. They were subsequently evaluated under controlled laboratory conditions using a detached leaf technique with three pathotypes, designated 29R45 (12-5), 121R63-1 (77-5) and 21R55 (104-2).They were also tested in the field. Genotypes, G-5, G-11, G-12 and G-13 showed the lowest disease severities, very close to immunity, against all three pathotypes. In addition, 10 tightly linked microsatellite markers were also used to characterize the 15 lines for presence or absence of the known slow rusting leaf rust resistance genes.

Global Wheat Program

Text in English

INT2917|INT0610

CIMMYT Staff Publications Collection