Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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Comparison of reactions of some wheat genotypes at adult
plant stage to Puccinia striiformis f.sp. tritici.
F. Afshari, 1 M.R.J. Kamali 1 and S. Rajaei 2
1. Seed and Plant Improvement Institute (SPII), Karaj, Islamic Republic of Iran;
2. Agricultural and Natural Resources Research Centers of Fars, Islamic Republic of
Iran
In order to identify resistance in genotypes of wheat at the adult plant stage, a
field experiment was carried out in Karaj and Zargan in the 2005/06 cropping
season. All 56 genotypes together with a susceptible landrace (Bolani) were
sown in two 1-m long rows 30 cm apart, under artificial inoculation with race
134E134A+ in Karaj and race 166E134A+SK+ on the Zargan experimental field
station. The first pathotype has shown virulence on plants with Yr2, Yr6, Yr7,
Yr9 and YrA, and the second pathotype has recently become dominant in
central Iran (Fars province), with virulence on plants with genes Yr2, Yr6, Yr7,
Yr9, YrA, YrSD and Yr27(SK). A susceptible wheat landrace, Bolani, was
planted as spreader around the field experiment and among the rows. The
response of plants was evaluated using a modified Cobb’s Scale, at flag leaf
appearance. In the field, 52 genotypes were resistant to pathotype 134E134A+.
Only 18 genotypes showed resistance to both pathotypes. The remaining lines
and cultivars were scored moderately susceptible to susceptible. These
resistant lines will be either released as new cultivars or used as sources of
resistance in the national wheat breeding programmes.
Microsatellite-based detection of stripe [yellow] rust
resistance gene Yr24 in cv. Arrivato
S. Bhavani, 1 R.A. Hare 2 and H. S. Bariana 1
1. University of Sydney Plant Breeding Institute, Cobbitty, Camden, Australia;
2. New South Wales Department of Primary Industries, Agricultural Research
Institute, Calala Lane, Tamworth, Australia
The durum cv. Arrivato exhibits high levels of stripe [yellow] rust resistance.
Genetic analysis based on 198 F 3 families derived from a cross involving
Arrivato and the susceptible parent Bansi indicated digenic segregation for
stripe rust response in the seedling stage. Single-gene segregating populations,