Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

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pathogen population being persistent across years and exposed to limited
selection, i.e. presence of plenty of host plants with few or no Yr-genes.
We observed Central Asian isolates that were closely related to isolates
from the Mediterranean area and South Africa, and another group of isolates
had fingerprints that were almost similar to those of isolates from Europe and
NE Africa. This could suggest that spores of the yellow rust fungus potentially
may move across very large distances within a relatively short time, a fact that
highlights the need for multinational disease and pathogen surveys.
Breeding for durable stripe [yellow] rust resistance using
conventional and marker assisted selection in wheat
H.S. Bariana
University of Sydney Plant Breeding Institute, Cobbitty, Australia.
Wheat cultivation around the world has been severely affected for over a
decade by stripe [yellow] rust. Puccinia striiformis f.sp. tritici appears to have
acquired the ability to infect wheat at relatively higher temperatures. This
attribute has resulted in increased levels of this disease in geographical regions
that were traditionally thought to be at low risk for stripe rust. Although
combinations of major genes will not provide the sought-after durability, it
would increase genetic diversity. Pyramiding of three or more adult plant
resistance (APR) genes would ensure potential durability of resistance. This
investigation describes the identification, characterization and deployment of
stripe rust genes in new cultivars. Breeding strategies to achieve gene
combinations through marker assisted selection is also discussed. Practical
examples from the Australian wheat breeding experience are presented.