A ProMED-mail post
<http://www.promedmail.org>
ProMED-mail is a program of the International Society for Infectious Diseases <http://www.isid.org>

Date: October 2008
Source:  Australian Quarantine and Inspection Service (AQIS) Bulletin Sept/Oct 2008, p.7 [edited] <http://www.daff.gov.au/__data/assets/pdf_file/0009/865566/bulletin-septoct08.pdf>

In NSW, a recent consignment of wheat seed from Ethiopia was found to have fungal spores growing on it. These were identified as teliospore of _Puccinia graminis_ var _tritici_ stem rust of wheat [and suspected to be strain Ug99; see below - Mod.DHA]. This [strain of] stem rust is exotic to Australia and of high quarantine risk. It is
slowly spreading from Africa to the Middle East and is causing great concern among wheat breeders, as there are currently no genes available for resistance to its spread. Wheat is an economically important crop worth AUD 4.2 billion [USD 2.7 billion] annually in Australia, and this disease has the potential to devastate our industry. The entire consignment of wheat seed was destroyed with full agreement from the importers.

--
Communicated by:
ProMED-mail <promed@promedmail.org>

[Wheat stem rust is caused by the fungus _Puccinia graminis_ f. sp. _tritici_. Overall yield losses of up to 70 percent are reported, but some fields are totally destroyed. New races are emerging, and the most dangerous at present is strain Ug99, which has overcome the major resistance gene used in our current wheat varieties. It is
estimated that Ug99 could reduce world wheat production by 60 million tons (for more information on stem rust and Ug99, please see previous ProMED-mail posts and links listed below).

Ug99 is spreading eastwards from its origin in Uganda and is now considered to be present in much of East Africa, including Ethiopia. At this time, Ug99 has apparently not spread beyond the Middle East, and other strains of stem rust are present in Australia (an outbreak was reported recently from Western Australia, ProMED-mail post no. 20080905.2769). However, due to its origin, the rust found on the Ethiopian wheat was considered likely to be Ug99 (AQIS NSW, personal communication), and, therefore, the seed was destroyed. This quarantine interception was a narrow escape illustrating the vital role of quarantine inspections. Any wheat import consignment from a
Ug99 area must be considered of extremely high risk.

Maps
Australia:
<http://www.ga.gov.au/image_cache/GA4073.jpg>  and
<http://healthmap.org/promed/en?v=-25.7,134.5,4>
NSW:
<http://www.ozhorizons.com.au/nsw/map.htm>

Pictures of stem rust symptoms:
<http://www.cimmyt.org/english/wps/news/2005/sept/images/stem2.jpg>  and
<http://www.gov.mb.ca/agriculture/crops/diseases/images/fac15s01.jpg>

Links
Information on wheat stem rust:
<http://www.ars.usda.gov/Main/docs.htm?docid=9910>
Information on Ug99:
<http://www.agbioworld.org/newsletter_wm/index.php?caseid=archive&newsid=2686>
and
<http://www.pestalert.org/viewNewsAlert.cfm?naid=36>
Ug99 distribution and potential global impact:
<http://www.cimmyt.cgiar.org/gis/pdf/UG99postH.pdf>
Ug99 resistance breeding programmes:
<http://blog.cimmyt.org/?p=406>  and
<http://www.pabic.com.pk/25%20September,%2008%20AARI%20deve%20UG99.html>
_P. graminis_ f.sp. _tritici_ taxonomy:
<http://www.indexfungorum.org/Names/NamesRecord.asp?RecordID=455607>
Global Rust Initiative:
<http://www.globalrust.org/>
- Mod.DHA]

[see also in the archive:
Wheat stem rust, strain Ug99 - multicountry: update 20081120.3660
Stem rust, wheat - Australia: (WA) 20080905.2769
Wheat stem rust, strain Ug99 - Iran: 1st rep, alert 20080307.0925
2007
----
Wheat stem rust, strain Ug99 - Kenya: new variant 20071217.4054
Wheat stem rust, strain Ug99 - multistate: resistance screening 20071208.3957
Barley yellow dwarf virus & stem rust, cereals - Kenya 20070705.2132
Wheat stem rust, strain Ug99 - Yemen (02): government response 20070430.1399
Wheat stem rust, spread: FAO, Global Rust Initiative 20070414.1241
Wheat stem rust, strain Ug99 - Yemen: 1st report 20070117.0229
2006
----
Wheat stem rust, strain Ug99 - Pakistan: susp., 1st report 20060514.1366
Stem rust, wheat - multicountry: new strains 20060406.1039
2005
----
Wheat stem rust, Ug99, new strain - East Africa 20050928.2849
Wheat stem rust, new strain - Uganda 20050912.2698
2002
----
Wheat stem rust fungus, new virulence genes - So Afr 20020814.5049
2000
----
Wheat stem rust in resistant wheat lines - Uganda 20000702.1092
1999
----
Stem-rust fungus, mutant, wheat - Uganda 19990519.0812]

Clarification