Ug99 is a lineage of wheat stem rust (Puccinia graminis f. sp. tritici), which is present in wheat fields in several countries in Africa and the Middle East and is predicted to spread rapidly through these regions and possibly further afield, potentially causing a wheat production disaster that would affect food security worldwide.[1] In 2005 the noted green revolution pioneer Norman Borlaug brought great attention to the problem, and most subsequent efforts can be traced to his advocacy.[2] It can cause up to 100% crop losses and is virulent against many resistance genes which have previously protected wheat against stem rust.
Although Ug99-resistant varieties of wheat do exist,[2] a screen of 200,000 wheat varieties used in 22 African and Asian countries found that only 5-10% of the area of wheat grown in these countries consisted of varieties with adequate resistance.[1]
The original race of Ug99, which is designated as 'TTKSK' under the North American nomenclature system, was first detected in Uganda in 1998[3] and first characterised in 1999[3] (hence the name Ug99) and has since been detected in Kenya, Ethiopia, Eritrea, Sudan, Yemen, Iran, Tanzania, Mozambique, Zimbabwe, South Africa,[4] and Egypt. There are now 15 known races of Ug99.[5] They are all closely related and are believed to have evolved from a common ancestor, but differ in their virulence/avirulence profiles and the countries in which they have been detected.[1]
^ abcCite error: The named reference Singh11 was invoked but never defined (see the help page).
^ abGross, Michael (2013). "Pests on the move". Current Biology. 23 (19). Cell Press: R855–R857. Bibcode:2013CBio...23.R855G. doi:10.1016/j.cub.2013.09.034. ISSN 0960-9822. PMID 24251330. S2CID 15559913.
^ ab
• Pretorius, Z. A.; Singh, R. P.; Wagoire, W. W.; Payne, T. S. (2000). "Detection of Virulence to Wheat Stem Rust Resistance Gene Sr31 in Puccinia graminis. f. sp. tritici in Uganda". Plant Disease. 84 (2). American Phytopathological Society: 203. doi:10.1094/pdis.2000.84.2.203b. ISSN 0191-2917. PMID 30841334. S2CID 73469939.
• Singh, Ravi P.; Hodson, David P.; Huerta-Espino, Julio; Jin, Yue; Bhavani, Sridhar; Njau, Peter; Herrera-Foessel, Sybil; Singh, Pawan K.; Singh, Sukhwinder; Govindan, Velu (8 September 2011). "The Emergence of Ug99 Races of the Stem Rust Fungus is a Threat to World Wheat Production". Annual Review of Phytopathology. 49 (1). Annual Reviews: 465–481. doi:10.1146/annurev-phyto-072910-095423. ISSN 0066-4286. PMID 21568701. S2CID 24770327.
• Singh, Ravi P.; Hodson, David P.; Huerta-Espino, Julio; Jin, Yue; Njau, Peter; Wanyera, Ruth; Herrera-Foessel, Sybil A.; Ward, Richard W. (2008). "Will Stem Rust Destroy the World's Wheat Crop?". Advances in Agronomy. Vol. 98. Elsevier. pp. 271–309/xiii+422. doi:10.1016/s0065-2113(08)00205-8. ISBN 9780123743558. ISSN 0065-2113. S2CID 55174564.
^Hodson, D. P.; Grønbech-Hansen, J.; Lassen, P.; Alemayehu, Y.; Arista, J.; Sonder, K.; Kosina, P.; Moncada, P.; Nazari, K.; Park, R. F.; Pretorius, Z. A.; Szabo, L. J.; Fetch, T.; Jin, Y. "Tracking the Wheat Rust Pathogens" (PDF). 2012 Borlaug Global Rust Initiative Technical Workshop Proceedings. Borlaug Global Rust Initiative. Archived (PDF) from the original on October 5, 2019. Retrieved 28 November 2012.
^"Pathotype Tracker – Where is Ug99?". The International Maize and Wheat Improvement Center.
Ug99 is a lineage of wheat stem rust (Puccinia graminis f. sp. tritici), which is present in wheat fields in several countries in Africa and the Middle...
wheat strains show no resistance. The race was named TTKSK (e.g. isolate Ug99). An epidemic of stem rust on wheat caused by race TTKSK spread across Africa...
f. sp. tritici and carries Sr52 which offers some resistance against the Ug99 subrace of P.g.f.sp.t.. The genetic basis for this immunity is being introgressed...
convened an international expert panel in Kenya on the emerging threat of Ug99 in east Africa. The working group produced a report, "Sounding the Alarm...
intensive farming". Archived from the original on 3 May 2007. "Wheat Stem Rust – UG99 (Race TTKSK)". FAO. Archived from the original on 7 January 2014. Retrieved...
coloured by its spores. A virulent form of the wheat disease, stem rust, strain Ug99, spread from Africa across to the Arabian Peninsula by 2007. In field trials...
humanity's third-most-produced cereal. Extant fungal infections such as Ug99 (a kind of stem rust) can cause 100% crop losses in most modern varieties...
availability especially if there are no contingency plans in place. For example, Ug99, a lineage of wheat stem rust, which can cause up to 100% crop losses, is...
epidemic of stem rust, which is destructive to wheat and is caused by race Ug99, has in 2007 spread across Africa and into Asia. Beginning in the 20th century...
detailing the threat to global wheat supplies posed by the stem rust variant Ug99. The report sounded the alarm to risks facing wheat supplies in Kenya, Ethiopia...
David P.; Huerta-Espino, Julio; et al. (2011-09-08). "The Emergence of Ug99 Races of the Stem Rust Fungus is a Threat to World Wheat Production". Annual...
continent's harvest. As such the Puccinia graminis f. sp. tritici (Pgt) strain Ug99 is a tremendous forward looking concern and Plant Health Australia, Grains...
threatens the Ethiopian harvest every year and recently that especially means Ug99. Resultantly there has been significant uptake of resistant wheat varieties...
migration and strategies to mitigate the threat to wheat production from rzace Ug99 (TTKS) of stem rust pathogen". CABI Reviews. 2006. CABI Publishing. doi:10...
situation in Lebanon. During this time she put together definitive evidence that Ug99 had not yet reached the country. In 2020, she was recognised in the BBC's...
to consider a response to the threat the global food supply posed by the Ug99 strain of wheat rust. The BGRI was renamed the Borlaug Global Rust initiative...
Zadoks, J.C. (2014). "Epidemiological analysis of the damage potential of Pgt-Ug99 in Central, North East Africa; Iran and Punjab (India)". Indian Phytopathology...
for his essential leadership efforts to contain and reduce the impact of Ug99, a devastating new race of the stem rust pathogen that poses a serious threat...
original on 16 August 2017. Retrieved 15 January 2014. "The Red Menace: UG99 Threatens Afghan Wheat Production, Mail Fights Back". US Embassy Kabul. 3...
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