Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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trial. Yellow rust uredospores collected the previous year in Haymana were
preserved in liquid nitrogen until a spore suspension was prepared with mineral
oil (Soltrol 170). Uniform epidemics resulted from the artificial inoculations.
Thus, disease severity of susceptible genotypes reached 90S to 100S at scoring
time. Disease severity was first scored in June. A minimum of two readings
were done and the highest score was used for selection of the genotypes. At
adult plant stage, infection type (IT) of each entry was evaluated and
percentage leaf area affected (disease severity) was also scored using the
modified Cobb’s scale. Then Coefficients of Infection (CI) were calculated by
combining IT and disease severity. In total, 204 bread and 48 durum winter
wheat genotypes were resistant to yellow rust. For spring wheat genotypes, 77
bread and 19 durum entries were resistant to yellow rust. Additionally, we
found that 176 winter bread wheat genotypes were resistant to both yellow and
leaf rust, 57 winter bread wheat genotypes were resistant to both bunt and
yellow rust, and 80 winter bread wheat genotypes were resistant to both loose
smut and yellow rust. Based on these results, we can use these genotypes as
resistant germplasm for registration or crossing programmes.
Determination of yellow rust resistance in some
International Winter Wheat Improvement Programme
(IWWIP) nurseries in central Anatolia
Z. Mert, 1 K. Akan, 1 L. Çetin, 1 F. Düşünceli, 1 A. Morgunov, 2 M. Keser 3 and B. Akın 2
1. Central Research Institute for Field Crops, Yenimahalle, Ankara, Turkey;
2. CIMMYT Office, Ankara, Turkey. 3. ICARDA Office, Ankara, Turkey
Yellow rust caused by Puccinia striiformis f.sp. tritici is one of the important
diseases on cereal crops worldwide, causing yield and quality loss in wheat
under epidemic conditions. Genetic resistance is the most economical and
environmentally safe control measure, so use of genetic resistance and
development of resistant cultivars are very important to control the disease. The
International Winter Wheat Improvement Programme (IWWIP) main objective
is to develop winter and facultative wheat germplasm for the Central and West
Asia region. IWWIP also facilitates winter wheat germplasm exchange for the
global breeding community. The purpose of the study was to determine the
resistance at the adult plant stage of some genotypes from IWWIP against
yellow rust under artificial epidemic conditions in Ankara in the 2007/08
growing season. The experiment was conducted at the Research Station of the
Central Research Institute for Field Crops (CRIFC) in Haymana, Ankara. A
total of 2156 wheat cultivar and lines were used in 15 nurseries. Each wheat
cultivar or line was sown by hand in a row 1-m long in October 2007. Cv. Little