Doubled haploid populations of CD87/Katepwa, Cranbrook/Halberd, and
Sunco/Tasman were assessed for seedling response to stem rust and stripe
rust. The CD87/Katepwa population was also screened as adult plants in the
field against stripe rust. The respective parents differed in presence or
absence of various stem rust and stripe rust resistance genes. At least 4
resistance loci controlled adult plant resistance to stripe rust in the
CD87/Katepwa population, and based on quantitative trait loci mapping
results, two of these were contributed by CD87. Pedigree information indicated
that these regions correspond to durable adult plant stripe rust resistance
genes Yr18 and Yr29.
Yr29 was mapped to the distal region of chromosome 1BL.
The third gene, contributed by Katepwa, YrKat, was
located in chromosome arm 2DS. Sr30 mapped distal to
markers abg3 and P36/M61-170 in chromosome arm 5DL. Genes
Yr7 and Pbc (completely linked
with durable stem rust resistance gene Sr2) showed close
associations with markers in chromosome arms 2BL and 3BS, respectively. A
distally located genomic region in chromosome 6AS also affected the expression
of Pbc. The temperature-sensitive stripe rust resistance
gene, YrCK, carried by Sunco showed monogenic
inheritance and was located in chromosome arm 2DS. Several markers showed
complete association with Triticum timopheevi derived
stem rust resistance gene Sr36. Microsatellite markers
stm773 and gwm271A were validated on a set of wheat genotypes and were found
to be diagnostic for the detection of Sr36.
TheSr36-linked Xstm773 allele
showed better amplification than the Sr36-linked
Xgwm271A allele. These markers could be used for marker
assisted identification of Sr36 in breeding populations.
Stripe rust resistance gene Yr34 (synonym Yr48) is located within a distal translocation of Triticum monococcum chromosome 5AmL into common wheat
