Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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Resistance evaluation of elite wheat lines to yellow rust in
Ardabil
G. R. Aminzadeh and S.A. Safavi
Agricultural Research and Natural Resources Centre of Ardabil, Ardabil, Islamic
Republic of Iran
Yellow rust or stripe rust (caused by Puccinia striiformis f.sp. tritici) is the most
important disease of wheat in Iran, causing high yield losses in epidemic years.
The use and production of resistant cultivars is the best controlling method for
the disease. For this purpose, reaction evaluation of 15 genotypes (ERWYT-C-
82 entries) to yellow rust was carried out under field conditions using mist
irrigation in 2004 and 2005. In addition, artificial inoculation of the nursery was
done by mixing of spores with talcum powder and using a duster at sunset
time, and applied before flag leaf development. At the adult plant stage,
infection type (IT) of each entry was evaluated based on Roelfs et al. method.
The percentage leaf area affected (disease severity) was also scored using the
modified Cobb’s scale. Coefficients of Infection (CI) were calculated by
combination of IT and disease severity. Results showed that for ERWYT
entries, 26.6% of genotypes were resistant (CI = 0–2), 20% moderately resistant
(CI = 3–4), 26.63% moderately susceptible (CI = 5–12), and 26.6% susceptible
(CI >12). In this research we also concluded that lines such as C-82-1, C-82-12
and C-82-13 were moderately susceptible or susceptible because they had
CI >16. Other lines, especially C-82-3, C-82-4, C-82-6, C-82-8, C-82-10 and C-82-
15, were selected for their resistance reaction to yellow rust and other desirable
characters.
Postulation of stripe [yellow] rust resistance genes in entries
of the 35th International Bread Wheat Screening Nursery
N.A. Dadkhodaie, 1 R.F. Park 1, 2 and C.R. Wellings 1
1. University of Sydney, Plant Breeding Institute Cobbitty, Camden, Australia;
2. Seconded from NSW Department of Primary Industries
The 35th International Bread Wheat Screening Nursery (IBWSN), distributed
by the International Wheat and Maize Improvement Centre in Mexico
(CIMMYT), was assessed for stripe [yellow] rust resistance using selected