Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

350
Evaluation of bread and durum
wheat lines and genotypes for
rusts under Menemen conditions
of Turkey
R. Ünsal , H. Geren and Đ. Sevim
Aegean Agricultural Research Institute, Izmir, Turkey
Abstract
Wheat rusts are very important on the Aegean Coast. The climate of the region
is often conducive to epidemics. Varieties possessing various resistance genes
for rust have helped prevent epidemics. The major means of protection against
the disease is development and utilization of genetically resistant wheat
varieties. Every year in the period 2003–2007 more than 15 000 bread wheat
and durum wheat accessions used in two regional breeding programmes
implemented in the Aegean Agricultural Research Institute have been screened
for resistance to rusts. Studies have shown that stripe [yellow] rust (Puccinia
striiformis f.sp. tritici) resistance genes Yr2, Yr6, Yr7, Yr9, Yr11, Yr12, Yr18 and
YrA are not effective in the Aegean area. For leaf rust (Puccinia triticina) the
only effective genes were Lr29, Lr36 and Lr37.
Introduction
The fact that Mendel’s laws are valid for resistance to plant diseases was first
demonstrated in wheat in 1905 (Biffen, 1905). Studies conducted in the last
century on the genetics of rust disease, which has the most important place
among wheat diseases, revealed that the most effective method for disease
control is to grow resistant varieties (Wiese, 1977). The fact that rust spores can
be carried by wind long distances in a very short time and the pathogen being
very dynamic makes the continuing search for resistance genes necessary
(Stubbs et al., 1986).
Along the Aegean coastline, leaf diseases and irregular rainfall come first
among the factors restricting productivity. Although it was widely advertised
both verbally and in print that a new species of yellow rust had been found in
the Aegean Region in 1995, extensive loss occurred in 1997 due to that yellow
rust race because the farmers in Söke plain insisted on growing the Serial 82
cultivar that was known to be susceptible. Studies to determine yellow rust