Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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Study of selected wheat genetic
resources for yellow rust
resistance in Uzbekistan
Z. Khalikulov, 1 Z. Ziyaev, 2 A. Amanov, 3 S. Alikulov 2 and R.C. Sharma 1
1. ICARDA, Central Asia and the Caucasus Regional Programme, Tashkent,
Uzbekistan
2. Uzbek Research Institute of Plant Industry, Tashkent, Uzbekistan
3. Principal Consultant to the President's Office, Uzbekistan
Abstract
Yellow rust, caused by Puccinia striiformis f.sp. tritici, is an important disease of
wheat (Triticum aestivum L.) in Central Asia and many other wheat growing
regions in the world. Wheat breeders continuously seek new sources of
resistance for improving resistance of commercial cultivars. A field study was
conducted using 272 wheat accessions in Uzbekistan in the 2008–2009 wheat
growing season. The germplasm derived from Uzbekistan (59 entries);
International Winter Wheat Improvement Programme, a cooperative breeding
project between the Ministry of Agriculture and Rural Affairs of Turkey,
CIMMYT and ICARDA) (103 entries); Russia (82 entries); Italy (10 entries);
Ukraine (10 entries); and USA (7 entries). Approximately 90% of the
germplasm represented wheat developed for irrigated conditions. Since there
were severe epidemics of wheat yellow rust in Uzbekistan in 2009, the
germplasm was indeed evaluated under heavy natural inoculum pressure.
This was confirmed by 100% yellow rust severity on several susceptible
genotypes. A quarter of the accessions (68 out of 272) showed high levels of
resistance to yellow rust, while 33% of entries (91 out of 272) were highly
susceptible (>60% severity). Many accessions resistant to yellow rust also
showed resistance to leaf rust; a few were resistant to powdery mildew as well.
In a situation where most of the commercial cultivars in Uzbekistan showed
high levels of susceptibility to yellow rust in 2009, the resistant genotypes
identified in this study are valuable wheat genetic resources. The genotypes
with resistance to yellow rust, leaf rust and powdery mildew could prove
outstanding parents to improve resistance to these three most important
diseases of winter wheat under irrigated management condition.