194
of 198 accessions of T. urartu tested were resistant to leaf rust. No resistance to
Hessian fl y, greenbug, or WSMV was detected. A novel leaf rust resistance gene
from T. monococcum has been introgressed onto chromosome 5AS and is indepen-
dent of a FHB QTL also located on that chromosome arm (Fedak et al. 2006 , 2011 ).
Since there are no other leaf rust resistance genes mapped on that chromosome, this
gene must be unique (McCallum p.c.). The introgressed line designated as M321 is
shown in Fig. 8.1 as a fi eld plot. There is no obvious linkage drag associated with
this introgression. In Fig. 8.1 M321 is shown adjacent to a plot of AC Barrie show-
ing the difference in leaf rust infection. AC Barrie is a widely grown Canadian cul-
tivar of hard red spring wheat that has been recently overcome by leaf rust.
8.1.2.3 Stripe Rust Resistance
Although T. monococcum is a good source of genes for resistance to leaf rust, it has
not provided many genes for resistance to stripe rust. Adult plant stripe rust resis-
tance was detected in strain pau14087 of T. monococcum and strain pau5088 of T.
boeoticum (Chhuneja et al. 2008 ). A mapping population was created from a hybrid
between the two strains. The resistance locus in T. monococcum mapped to chromo-
some 2A and to chromosome 5A in T. boeoticum. Selected R1L were used to trans-
fer the resistance to hexaploid wheat using T. durum as a bridge. The B genome of
durum suppressed the resistance in F1 plants but this was overcome by several back-
crosses. The resistance gene from T. boeoticum was successfully transferred to
hexaploid wheat (Chhuneja et al. 2008 ). Seedlings of 75 accessions of T. boeoticum ,
12 of T. monococcum , 16 of T. urartu , 230 of durum wheat and 128 amphiploids
AAAABB were evaluated for stripe rust resistance in fi eld and greenhouse condi-
tions (Ma et al. 1997 ). Resistant reactions were observed on 10 accessions of T.
boeoticum , 19 accessions of durum, and 32 amphiploids. Suppressions of resistance
were common in the A and AB genomes and were resistance gene specifi c.
Fig. 8.1 A fi eld plot of T. monococcum -derived line M321 showing leaf rust resistance. The adjacent
plot of AC Barrie is susceptible to leaf rust
G. Fedak