Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

Evaluation of Indian wheat
genotypes for slow-rusting
resistance to stripe [yellow] rust
under artificially inoculated
conditions
M.S. Saharan, A.K. Sharma, M. Singh and S.S. Singh
Directorate of Wheat Research, Carnal, Haryana, India
Abstract
Wheat rust diseases—stripe or yellow rust; leaf or brown rust; stem or black
rust—are common fungal foliar diseases in many regions of the world,
including India. Yellow rust of wheat, caused by Puccinia striiformis West. f.sp.
tritici, inflicts heavy yield losses in northern parts of India if cool and humid
weather prevails between December and March. Use of genetic host resistance
is the most effective, economical and eco-friendly approach for rust control.
Resistance breeding resulted in the release of several rust-resistant varieties
during the post-Green Revolution period in India. However, evolution of new
pathotypes in rusts always posed challenges in wheat rusts management in
India. Slow-rusting is a form of resistance where a susceptible host reaction is
observed but the rate of disease development is slower than in susceptible
cultivars. In trials, 114 wheat genotypes (41 advanced entries, 73 checks) of
advanced varietal trial (AVT)-2nd year and 126 entries of AVT-1st year were
inoculated with prevalent pathotypes of yellow rust (67S8, 47S102, 46S103,
70S69, 46S119, 78S84) at Karnal during the 2008/09 crop season.
Rust intensities recorded at equal intervals were analysed using the Area
Under Disease Progress Curve (AUDPC) technique and genotypes were
categorized into distinct groups. Group I included 127 genotypes (69 entries +
58 checks) that exhibited AUDPC values