Sydney, Australia
July 30, 2008
Source: The University of Sydney,
Plant Breeding Institute Cobbitty,
Cereal Rust Laboratory
2007-2008 CEREAL RUST SURVEY -
ANNUAL REPORT
SUMMARY
The 2007-08 survey ended on
March 31 2008. A total of 435 samples were received from
collaborators around Australia. With the exception of stripe
rust in eastern Australia, the overall incidence of cereal
rusts across the national cereal growing regions during the
2007 cropping cycle was low due to dry conditions in certain
areas and the cultivation of rust resistant varieties. Only
one new pathotype (wheat stripe rust) was detected.
Wheat stem rust: A total of 24 samples were received,
few, if any, originated from commercial wheat crops. Only 3
pathotypes were isolated, viz. 34-1,2,7 +Sr38 (most
frequent), 34-1,2,7 +Sr38 +Norin 40, and 98-1,2,3,5,6.
Wheat leaf rust: Only 18 samples of leaf rusted wheat
were received, from which pathotypes 104-
1,2,3,(6),(7),9,11; 104-1,2,3,(6),(7),11 +Lr37; 76-3,5,9,10
+Lr37; and 10-1,3,9,10,12 were isolated. The latter two
pathotypes, first detected in Australia in 2004 and 2005,
respectively, are believed to have been introduced to
Australia from an unknown source.
Wheat stripe rust: Unexpected severe rusting on
certain triticale cultivars, notably Jackie, was
subsequently shown to be the result of a new pathotype
designated 134 E16 A+ J+, and given the common name ‘Jackie
pathotype’. The inclusion of a triticale in the differential
set provided evidence for the widespread distribution of
this pathotype in eastern Australia. In the first year of
its detection, this pathotype assumed 25% of isolates among
a collection of 338 rust samples received during the season.
The pathotype with virulence for Yr17 that was first
detected late in the 2006 season increased in frequency in
2007 to 13% of isolates. The distribution of these new
pathotypes includes all eastern states with the exception of
Queensland where the ‘WA Yr17 pathotype’ was not detected.
Oat crown rust: From the 24 samples received, 10 of
which were from wild oats, four pathotypes were identified:
0001-0, 0000-2, 0107-4,6,10, and 0307-4,6,10 +Nugene. As in
previous years, pts 0001-0 and 0000-2 were isolated from
eastern and Western Australia, while the latter two
pathotypes were only isolated from northern NSW.
Oat stem rust: Low sample numbers was a feature in
2007, with the majority originating from South Australia and
Western Australia. Virulence for Pga was not detected,
although this may have reflected low sample numbers.
Barley leaf rust: Only 14 samples were received, from
which three pathotypes were recorded: 5453P- and 5453P+
(from northern NSW, Vic, SA and WA) and 220P+ (from SA
only).
Barley stem rust: Four samples of stem rusted barley
were forwarded from Qld and northern NSW,
however, only one yielded a viable isolate which was
identified as the “scabrum” rust with added virulence for
Sr21.
Barley grass stripe rust: BGYR remained at low levels
in eastern Australia during 2007.
Triticale and rye rusts: There were no reports of stem rust
or leaf rust in commercial triticale and rye crops during
the 2007 cropping cycle. There were, however, many reports
of stripe rust in triticale, associated with the new
triticale attacking pathotype.
Full report:
http://www.agric.usyd.edu.au:8888/pbi/pdf_files/cereal_rust_survey_2007_08.pdf
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Cereal Rust Report
Season 2008 |
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Stripe rust pathotypes
detected early in season 2008
Mild early winter conditions in
eastern Australia and the early
detection of stripe rust in
commercial fields has
resulted in an unusually high
number of stripe rust samples
submitted to the PBI Cereal Rust
Laboratory. The first
sample was received in mid May
from off-type plants in a field
of Tobruk triticale at Young,
southern NSW. The
pathotype was shown to be 134
E16 A+ J+, ie the ‘Jackie’
pathotype (for details see
Cereal Rust Report Volume 6,
Number 2, June 2008).
Full
report
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