Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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sown by hand in rows 1 to 2 m long, with a differential after every 10 entries.
The nurseries were sown in 10 locations and irrigation was provided where
facilities were available. In 2005, stripe [yellow] rust was recorded at low
severity levels at the Eskişehir and Samsun locations, but severity was high in
Ankara owing to irrigation and artificial inoculation. In other locations, dry
conditions were unfavourable for disease development. The study indicated
that of the 1219 entries from the winter wheat breeding programmes, 106
(27.3%) showed good levels of resistance to yellow rust, while the number of
yellow rust-resistant entries among the 584 entries from the spring wheat
breeding programmes was 355 (61%). In total, 689 (38.2%) entries were found
to have good levels of resistance. The data from the yellow rust trap nursery
indicated that Yr1, Yr3V, Yr4+, Yr5, Yr15, YrSP and YrCV. were still resistant,
while other differentials were scored susceptible, intermediate or variable. The
resistance sources identified through the activity have been distributed to all
the programmes.
Slow-rusting resistance: a strategy to enhance durability of
yellow rust resistance in bread wheat in the Central and
West Asia and North Africa (CWANA) Region
O. Abdalla, S. Yaljarouka and A. Yahyaoui
ICARDA, Aleppo, Syria
In the Central and West Asia and North Africa (CWANA) Region, bread wheat
is the most important food crop. However, both productivity and total wheat
production in CWANA are generally low, failing to meet an increasing
demand for wheat products. This is partly due to the many abiotic stresses,
mainly drought, and to biotic stresses, particularly foliar diseases, that
significantly affect wheat production in CWANA. Yellow [stripe] rust caused
by the fungus Puccinia striiformis West. f.sp. tritici is a major foliar disease of
wheat in CWANA. In the past decade, severe yellow rust epidemics occurred
in a number of countries in Central and West Asia and caused significant yield
losses (10 to 40%). Because of both its ability to form new races and its airborne
dispersal mechanism, yellow rust continues to threaten stable wheat
production in CWANA.
Genetic resistance is widely used for the control of rust diseases and is
recognized as the most economical and environmentally friendly control
measure. The past three decades witnessed notable progress in breeding for
rust resistance. However, until recently, most of the resistance used has usually