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ARS Home » Midwest Area » St. Paul, Minnesota » Cereal Disease Lab » Research » Publications at this Location » Publication #321748

Research Project: CEREAL RUST FUNGI: GENETICS, POPULATION BIOLOGY, AND HOST-PATHOGEN INTERACTIONS

Location: Cereal Disease Lab

Title: First Report of the Ug99 race group of wheat stem rust, Puccinia graminis f. sp. tritici, in Egypt

Author
item Patpour, Mehran
item Hovmoller, Mogens
item Newcomb, Maria
item Olivera, Pablo
item Jin, Yue
item Luster, Douglas - Doug
item Hodson, David
item Nazari, Kumarse
item Shahin, Atef
item Azab, Mustafa

Submitted to: Plant Disease
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 10/19/2015
Publication Date: 3/23/2016
Citation: Patpour, M., Hovmoller, M., Newcomb, M., Olivera, P., Jin, Y., Luster, D.G., Hodson, D., Nazari, K., Shahin, A., Azab, M. 2016. First Report of the Ug99 race group of wheat stem rust, Puccinia graminis f. sp. tritici, in Egypt. Plant Disease. 100(4):863.

Interpretive Summary: Since the first detection of Ug99 (or race TTKSK) of Puccinia graminis f. sp. tritici in Uganda in 1998, it has been a priority to track further spread to other wheat growing areas. In the 2014 crop season in Egypt, the presence of virulence to Sr31 in Egypt was suspected based on preliminary field observations at several locations in Egypt: Sakha Agricultural Research Station in Kafrelsheikh, Al- Sharqyia, and Nubaria. Stem rust samples from these locations were analyzed at the Global Rust Reference Center (GRRC, Denmark) and USDA-ARS Cereal Disease Laboratory (CDL, USA). Three races in the Ug99 race group were detected, TTKST, TTKTK, and TTKSK. This is the first confirmation of races in the Ug99 race group in Egypt, thereby extending the geographical distribution of Ug99-related races. This information aids scientists in global monitoring Ug99.

Technical Abstract: Since the first detection of Ug99 (or race TTKSK) of Puccinia graminis f.sp. tritici (Pgt) in Uganda in 1998 (Pretorius et al. 2000), it has been a priority to track further spread to other wheat growing areas. To date, variants in the Ug99 race group have been detected in 12 countries, i.e., Uganda, Kenya, Ethiopia, Sudan, Tanzania, Eritrea, Rwanda, South Africa, Zimbabwe, Mozambique, Yemen and Iran. In the 2014 crop season in Egypt, the presence of virulence to Sr31 in Egypt was suspected based on preliminary field observations at the following locations: 1) Sakha Agricultural Research Station in Kafrelsheikh (?°?'S, ?°?'E), 2) Al- Sharqyia (?°?'S, ?°?'E), [please add more…], and 3) Nubaria. At Sakha wheat cv. PBW343 (carrying Sr31) were scored 30MR-S, and the monogenic line Benno Sr31/6*LMPG were scored 20MS-S at Al-Sharqyia. Three samples from each of these lines were sent to the Global Rust Reference Center (GRRC, Denmark). At Nubaria, stem rust samples were on a number of lines, and were collected and sent to the Foreign Disease-Weed Science Research Unit (MD, USA). Urediniospores of the samples were recovered on susceptible wheat cv. Morocco and McNair 701. Twenty-three and 11 single pustule isolates were derived and analyzed at GRRC and CDL, respectively using 20 North American stem rust differential lines following the race-typing procedure (Jin et al. 2008). In addition, three supplemental tester lines of Siouxland (carrying Sr24+Sr31), Sisson (carrying Sr31+Sr36), and Triumph 64 (donor of SrTmp) were included to confirm virulence/avirulence to Sr24, Sr31, Sr36, and SrTmp. The experiments were repeated two to three times. Two races in the Ug99 race group, TTKST (four isolates) from Al- Sharqyia, and TTKTK (13 isolates) from Sakha were found. Race TTKSK (2 isolates) was identified in a sample from Nubaria. This is the first confirmation of races in the Ug99 race group in Egypt, thereby extending the geographical distribution of Ug99-related races. Since Egypt may play a role as green-bridge for Pgt between East and North African countries and the wheat belts in Middle East and Mediterranean region, the rust surveillance efforts should be intensified in affected countries as well as in neighboring regions.