Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

Reaction of some international
wheat genotypes to yellow rust
at the adult-plant stage in Iran
A. Malihipour, 1 M. Torabi, 1 M.S. Ahmadian-Moghaddam 2 and A. Tarinejad 3
1. Cereal Pathology Unit, Cereal Research Department, Seed and Plant Improvement
Institute (SPII), Karaj, Islamic Republic of Iran
2. Mazandaran Agricultural Research Centre, Sari, Islamic Republic of Iran
3. Moghan Agricultural Research Centre, Parsabad, Islamic Republic of Iran
Abstract
In the present investigation, reactions of 140 bread and durum wheat
genotypes provided by ICARDA were assessed for yellow rust reaction at
three locations in Iran (Karaj, Sari and Moghan). Wheat entries were evaluated
under field conditions with artificial epidemic conditions to identify adult
plant resistance. The genotypes were planted in November 2000, at 10–15 g of
seed in two 1-m long rows spaced 30 cm apart. A susceptible cultivar (Bolani)
was planted among the experimental entries. Artificial inoculations of the
nurseries were done 4–5 times in a period of two months, starting at tillering
stage and using the relevant race for each location. The infection type (IT) of
each entry was evaluated when the disease developed well on the susceptible
check. The percentage leaf area affected was scored using Cobb’s modified
scale and at the same time coefficients of infection (CI) were calculated. A
heavy epidemic of the disease was established in the nurseries at all locations.
Based on data collected, most of entries were resistant to yellow rust in one or
more locations, and 132 entries were resistant at all locations. The results of
this research were sent to ICARDA for final analysis and to inform the
breeding programmes of the region.
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Introduction
Yellow [stripe] rust, caused by Puccinia striiformis f.sp. tritici, is one of the most
important diseases of wheat in the world. Yellow rust is principally a disease
of wheat grown in cooler climates (2–15°C), which are generally associated
with higher elevations, northern latitudes or cooler years. Losses can be severe
(50%) due to shrivelled grain and damaged tillers. In extreme situations, stripe
rust causes 100% loss.