Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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Effectiveness of yellow rust
resistance genes in Pakistani
wheats
S.D. Khanzada, 1 Azhar Rashid, 1 Naseer-ud-Din, 2 Attiq-ur-Rehman Rattu 3 and
Amir Raza 1
1. Nuclear Institute of Agriculture (NIA), Tando Jam, Hyderabad, Pakistan
2. Cereal Crops Research Institute (CCRI), Pirsabak, Nowshera, Pakistan
3. Crop Disease Research Programme (CDRE), IPEP, NARC, Islamabad, Pakistan
Introduction
Wheat, being the most important cereal food, plays a major role in nutrition of
the human population. It is the principal staple food crop and a source of
nutrition for the people of Pakistan. Annually, it is cultivated on an area of
8.5 million hectare to produce 21 million tonne of wheat, worth Rs 160 billion
(Anonymous, 2002b). In the wake of global warming, many environmental
stresses, including drought, rising temperatures, salinity, waterlogging and
erosion, have presented new challenges for wheat production. Abiotic stresses
are responsible not only for direct losses but also make crops more vulnerable
to biotic stresses like diseases and pest attacks. Amongst biotic stresses, new
races of cereal rust(s), powdery mildew and loose smut have evolved in space
and time.
In Pakistan, wheat has suffered heavy losses due to periodic epidemics
caused by leaf rust and yellow rust. Besides leaf rust, yellow rust, caused by
Puccinia striiformis Westend f.sp. tritici, has been a major problem in the hills,
foothills and plains of NWFP and Northern Punjab. These areas suffered losses
estimated at Rs 2.0 billion during 1994/95 and almost similar losses during
1995/96 (Ahmad, 2000). During 2002/03, areas under wheat in NWFP suffered
from huge losses due to yellow rust as a consequence of large-scale cultivation
of Inqilab 91. Recently, yellow rust has also been recorded infecting wheat in
the hotter and dryer climates of southern Punjab and Sindh. Over the years,
the threat of yellow rust has demanded far more attention and has occasionally
resulted in changes in the varietal spectrum in different areas of the country. In
view of the importance of the disease and its aftermaths, a yellow rust
monitoring programme has been carried out with the following objectives:
• To identify potential sources of yellow rust resistance.