Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

Agriculture-guided evolution of
pathotypes of Puccinia striiformis
Westend f.sp. tritici in Pakistan
Munawar Hussain, 1 M.A.S. Kirmani 1 and Ehsanul Haque 2
1. Crop Diseases Research Programme, National Agricultural Research Centre,
Islamabad, Pakistan
2. Crop Diseases Research Programme, Sunny Bank, Murree, Pakistan
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Introduction
Among the diseases of wheat (Triticum aestivum) prevalent in Pakistan, yellow
rust (stripe rust) is becoming increasingly important in the cooler northern
foothill areas of the Punjab, North West Frontier Province (NWFP), Azad
Jammu and Kashmir, uplands of Baluchistan and Kohistan, and to a lesser
extent in central Punjab and southern NWFP. It is practically absent from
Sindh.
Our present knowledge of yellow rust in the Indian sub-continent is mainly
based on the research work carried out by Mehta and co-workers. Mehta (1940)
reported isolating races 19, 31 and A of yellow rust during 1930–1937 from the
areas now forming Pakistan. Little work on identification of physiological
races prevalent in Pakistan has since been done, except for a few samples
collected from Murree that were analysed in 1965, which yielded races 20 and
31 (M. Hussain, unpublished). Vasudeva et al. (1952) identified yellow rust
races 19, A and G from East Punjab in 1950. Later, races 20, 19, 38, A, 14, 31,13,
57 and G were isolated from east Punjab during 1965–1969 (Joshi et al., 1977).
Thus the yellow rust races collected by Vasudeva et al. (1952) and Joshi et al.
(1977) prevalent in parts of India contiguous with Pakistan are likely to be
present here due to free exchange of inoculum between the two countries. This
assumption is further supported by the similarities of wheat rust races between
India and Pakistan (Hassan and Hussain, 1975; Hassan, Kirmani and Hussain,
1965; Hussain, Aslam and Kirmani, 1989; Kirmani, 1980; Kirmani et al., 1989;
Stubbs and Van Silfhout, 1977; Stubbs et al., 1974).
This paper presents the results of pathotyping and virulence evolution of
pathogenic races of yellow rust during 1969–1995.