Meeting the Challenge of Yellow Rust in Cereal Crops - ICARDA

infection of the pathogen for four years. To map the resistance gene(s) in the
genotype and transfer it into common wheat, a cross was made between
PI 480148 and susceptible common wheat genotype Avocet Susceptible.
Resistant F 3 plants with 42 chromosomes were selected through Feulgenstaining
of root tip cells and testing with Pst races. When tested with Pst-100,
the most predominant race in the USA for the last six years, 157 F 4 plants from
a single F 3 hexaploid plant segregated into a 3:1 ratio for resistance vs
susceptible plants, which identified a single dominant gene from PI 480148.
Using the F 3:4 population and the resistance gene-analogue polymorphism
(RGAP) and simple sequence repeat (SSR) markers, the gene was mapped to
the long arm of chromosome 2B. An RGAP marker and an SSR marker
(Xwmc441) were closely linked to the resistance gene with a genetic distance of
2.7 and 5.6 cM, respectively. The effective resistance of the gene to an
Australian isolate virulent to Yr5, which is located on 2BL and resistant to all
Pst races in the USA so far, indicated that the gene is different from Yr5 and
should be a new and useful gene for resistance to stripe rust. Resistant
common wheat lines with plant types similar to Avocet Susceptible were
selected for use in breeding programmes to develop common wheat cultivars
with the resistance gene.
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Evaluation of germplasm for resistance to yellow rust in
Ankara in the period 2000–2008
K. Akan, Z. Mert, L. Çetin and F. Düşünceli
Central Research Institute for Field Crops, Ankara, Turkey
Yellow rust caused by Puccinia striiformis f.sp. tritici is an important fungal
disease of wheat. The disease caused significant economic losses in the
Cukurova region in 1995. Losses were estimated at 500 000 t. Use of genetic
resistance and development of resistant cultivars are very important to control
the disease. In this respect, we evaluated the resistance of adult plants of
genotypes from breeding programme against yellow rust under artificial
inoculation in Ankara conditions during the period 2000–2008. The experiment
was conducted at the Central Research Institute for Field Crops (CRIFC) in
Ikizce-Haymana and Yenimahalle sites in Ankara, Turkey. Each genotype was
planted as a single row 1-m long. The trial was sown in October each year. The
experiment was conducted under natural conditions, supplemented by mist
irrigation. Cvs Little Club, Michigan Amber, Türkmen, Gerek 79, Seri 82 and
Gün 91 were sown around the experimental field. In addition, Little Club was
sown after every 10 entries and used as control and susceptible check in the