Physiological Races of <i>Puccinia graminis</i> f. sp. <i>tritici</i> in Ethiopia in 2019/2020

Kitessa Gutu; Tsegaab Tesfaye; Netsanet Bacha; Tamrat Negash; Daniel Kassa; Fikirte Yirga; Megersa Debela; Gudeta Bedada; Tesfaye Dessale; Ashenafi Gemechu; Tilahun Bayisa; Zerihun Eshetu; Zerihun Tomas; Girma Teshome; Mitiku Kebede; Bilal Temam; Misgana Mitiku; Bekele Kassa; Yitagesu Tadesse; Mequnanint Andualem; Tsehaye Brhane; Wulita Wondwosen; Nurhussen Seid; Zemedkun Alemu

doi:doi:10.11648/j.ajaf.20221002.15

Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020

Kitessa Gutu, Tsegaab Tesfaye, Netsanet Bacha, Tamrat Negash, Daniel Kassa, Fikirte Yirga, Megersa Debela, Gudeta Bedada, Tesfaye Dessale, Ashenafi Gemechu, Tilahun Bayisa, Zerihun Eshetu, Zerihun Tomas, Girma Teshome, Mitiku Kebede, Bilal Temam, Misgana Mitiku, Bekele Kassa, Yitagesu Tadesse, Mequnanint Andualem, Tsehaye Brhane, Wulita Wondwosen, Nurhussen Seid, Zemedkun Alemu

Published in American Journal of Agriculture and Forestry (Volume 10, Issue 2)

Received: 14 February 2022 Accepted: 3 March 2022 Published: 9 April 2022

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Abstract

Wheat stem rust caused by Puccinia graminis f.sp tritici is constant biotic constraint of wheat production across the world. Because of quick alteration of genetic makeup of wheat stem rust pathogen; monitoring shift in virulence within pathogen is crucial to avoid sudden occurrence of epidemics due race change. This study was to identify physiological races stem rust pathogen in Ethiopia during 2019 cropping season. Wheat stem rust samples were collected during 2019 main cropping season from major wheat growing areas of Oromia, Amhara, Tigray and Southern Nations Nationalities and Peoples regions of Ethiopia. Besides, samples were also collected from Afar region where wheat was grown by irrigation during off season. The samples where isolated on universally wheat stem rust susceptible line (McNair) for the sake of mono pustule isolation and multiplication to have sufficient spores. Each isolates where inoculated on twenty standard differential lines and each line was evaluated after fourteen days to determine the races. Eight stem rust races namely, TKKTF, TKTTF, TTTTF, TKKTT, TTKTT, TTRTF, TKPTF and TTKTF were identified from samples analyzed; TKKTF was identified from 175 (44.1%) stem rust isolates, while TTTTF was detected from 73 (18.4) samples analyzed. In addition, TKTTF was isolated from 70 (17.8%) samples; however, TTKTF, TTKTT, TTRTF, TKPTF and TKKTT were recorded from 48 (12.1%), 21 (5.3%), 4 (1%), 1 (0.25%) and 1 (0.25%) samples analyzed in the season. TTKTT races have 95% virulence spectra to stem rust resistance genes with in differential lines. Resistance genes (Sr24) that is available in most of commercial varieties worldwide became ineffective with these races. Therefore, breeding program should focus on searching for more sources of resistance to virulent races of the pathogen.

Published in	American Journal of Agriculture and Forestry (Volume 10, Issue 2)
DOI	10.11648/j.ajaf.20221002.15
Page(s)	72-76
Creative Commons	This is an Open Access article, distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution and reproduction in any medium or format, provided the original work is properly cited.
Copyright	Copyright © The Author(s), 2024. Published by Science Publishing Group

Keywords

Genes, Puccinia graminis, Races, Virulence

References

[1]	Admassu, B., Lind, V., Friedt, W. and Ordon, F. 2009. Virulence analysis of Puccinia graminis f. sp. tritici populations in Ethiopia with special consideration of Ug99. Plant Pathology 58 (2): 362 - 369.
[2]	Fetch Jr, T. G. and Dunsmore, K. M., 2004. Physiologic specialization of Puccinia graminis on wheat, barley, and oat in Canada in 2001. Canadian Journal of Plant Pathology, 26 (2), 148-155.
[3]	Hei, N. B., Tsegaab, T., Getaneh, W., Girma, T., Obsa, C., Seyoum, A., Zerihun, E., Nazari, K., Kurtulus, E., Kavaz, H. and Ozseven, I., 2020. First Report of Puccinia graminis f. sp. tritici Race TTKTT in Ethiopia. Plant Disease, 104 (3), 982.
[4]	Jin, Y., Szabo, L. J., Pretorius, Z. A., Singh, R. P., Ward, R. and Fetch Jr, T., 2008. Detection of virulence to resistance gene Sr24 within race TTKS of Puccinia graminis f. sp. tritici. Plant Disease, 92 (6), 923-926.
[5]	Lemma, A., Woldeab, G., Semahegn, Y. and Dilnesaw, Z., 2014. Survey and virulence distribution of wheat stem rust (Puccinia graminis f. sp. tritici) in the major wheat growing areas of central Ethiopia. Sci-Afric Journal of Scientific Issues, Research and Essays, 2 (10), 474-478.
[6]	Olivera Firpo, P. D., Newcomb, M., Flath, K., Sommerfeldt-Impe, N., Szabo, L. J., Carter, M., Luster, D. G. and Jin, Y., 2017. Characterization of Puccinia graminis f. sp. tritici isolates derived from an unusual wheat stem rust outbreak in Germany in 2013. Plant pathology, 66 (8): 1258-1266.
[7]	Olivera, P., Newcomb, M., Szabo, L. J., Rouse, M., Johnson, J., Gale, S., Luster, D. G., Hodson, D., Cox, J. A., Burgin, L., Hort, M., Gilligan, C. A., Patpour, m., Juatesen, A. F., Hovmoller, M. S., Woldeab, G., Hailu, E., Hundie, B., Tadese, K., Pumphrey, M., Sigh, R. P., and Jin, Y., 2015. Phenotypic and Genotypic Characterization of Race TKTTF of Puccinia graminis f. sp. tritici that Caused a Wheat Stem Rust Epidemic in Southern Ethiopia in 2013 – 14. Phythopathology 105 (7): 917–928.
[8]	Pathan, A. K. and Park, R. F. 2007. Evaluation of seedling and adult resistance to stem rust in European wheat cultivars. Euphytica 155: 87-105.
[9]	Patpour, M., Hovmøller, M. S., Hansen, J. G., Justesen, A. F., Thach, T., Algaba, J. R., Hodson, D. and Randazzo, B., 2018. Epidemics of yellow and stem rust in Southern Italy 2016-2017. In BGRI 2018. Retrieved on April, 2021 (https://www.globalrust.org).
[10]	Roelfs AP, Martens JW, 1988. An international system of nomenclature for Puccinia graminis f.sp. tritici. Phytopathology 78, 526-33.
[11]	Roelfs, A. P., R. P. Singh & E. E. Saari 1992. Rust Disesases of Wheat: Concept andMethods ofDisease Management. Mexico, D. F.: CIMMYT. 81 pages.
[12]	Stakman, E. C., D. M. Steward, W. Q. Loegering. 1962. Identification of physiologic races of Puccinia graminis var. tritici. US Dep. Agric. Agric. Res. Serv. E-617.
[13]	Stubbs RW, Prescott JM, Sarrri EE, Dubin H J, 1986. Cereal Disease Methodology Manual. CIMMYT, El Batan, Mexico, p. 51.
[14]	Woldeab G., Hailu E., and Bacha N., 2017. Protocols for Race Analysis of Wheat Stem Rust (Puccinia graminis f. sp. tritici). Ethiopian Institute of Agricultural Research, Ambo Plant Protection Research Center, Ethiopia. pp: 27.
[15]	Ayele Badebo and Bekele Hundie, 2016. Incidence and Challenges of Rust Diseases in Wheat Production. In: Containing the Menace of Wheat Rusts: Institutionalized Interventions and Impacts. Ethiopian Institute of Agricultural Research. pp: 153, Addis Abeba, Ethiopia.

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Kitessa Gutu, Tsegaab Tesfaye, Netsanet Bacha, Tamrat Negash, Daniel Kassa, et al. (2022). Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020. American Journal of Agriculture and Forestry, 10(2), 72-76. https://doi.org/10.11648/j.ajaf.20221002.15

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ACS Style

Kitessa Gutu; Tsegaab Tesfaye; Netsanet Bacha; Tamrat Negash; Daniel Kassa, et al. Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020. Am. J. Agric. For. 2022, 10(2), 72-76. doi: 10.11648/j.ajaf.20221002.15

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AMA Style

Kitessa Gutu, Tsegaab Tesfaye, Netsanet Bacha, Tamrat Negash, Daniel Kassa, et al. Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020. Am J Agric For. 2022;10(2):72-76. doi: 10.11648/j.ajaf.20221002.15

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@article{10.11648/j.ajaf.20221002.15,
  author = {Kitessa Gutu and Tsegaab Tesfaye and Netsanet Bacha and Tamrat Negash and Daniel Kassa and Fikirte Yirga and Megersa Debela and Gudeta Bedada and Tesfaye Dessale and Ashenafi Gemechu and Tilahun Bayisa and Zerihun Eshetu and Zerihun Tomas and Girma Teshome and Mitiku Kebede and Bilal Temam and Misgana Mitiku and Bekele Kassa and Yitagesu Tadesse and Mequnanint Andualem and Tsehaye Brhane and Wulita Wondwosen and Nurhussen Seid and Zemedkun Alemu},
  title = {Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020},
  journal = {American Journal of Agriculture and Forestry},
  volume = {10},
  number = {2},
  pages = {72-76},
  doi = {10.11648/j.ajaf.20221002.15},
  url = {https://doi.org/10.11648/j.ajaf.20221002.15},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajaf.20221002.15},
  abstract = {Wheat stem rust caused by Puccinia graminis f.sp tritici is constant biotic constraint of wheat production across the world. Because of quick alteration of genetic makeup of wheat stem rust pathogen; monitoring shift in virulence within pathogen is crucial to avoid sudden occurrence of epidemics due race change. This study was to identify physiological races stem rust pathogen in Ethiopia during 2019 cropping season. Wheat stem rust samples were collected during 2019 main cropping season from major wheat growing areas of Oromia, Amhara, Tigray and Southern Nations Nationalities and Peoples regions of Ethiopia. Besides, samples were also collected from Afar region where wheat was grown by irrigation during off season. The samples where isolated on universally wheat stem rust susceptible line (McNair) for the sake of mono pustule isolation and multiplication to have sufficient spores. Each isolates where inoculated on twenty standard differential lines and each line was evaluated after fourteen days to determine the races. Eight stem rust races namely, TKKTF, TKTTF, TTTTF, TKKTT, TTKTT, TTRTF, TKPTF and TTKTF were identified from samples analyzed; TKKTF was identified from 175 (44.1%) stem rust isolates, while TTTTF was detected from 73 (18.4) samples analyzed. In addition, TKTTF was isolated from 70 (17.8%) samples; however, TTKTF, TTKTT, TTRTF, TKPTF and TKKTT were recorded from 48 (12.1%), 21 (5.3%), 4 (1%), 1 (0.25%) and 1 (0.25%) samples analyzed in the season. TTKTT races have 95% virulence spectra to stem rust resistance genes with in differential lines. Resistance genes (Sr24) that is available in most of commercial varieties worldwide became ineffective with these races. Therefore, breeding program should focus on searching for more sources of resistance to virulent races of the pathogen.},
 year = {2022}
}

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TY  - JOUR
T1  - Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020
AU  - Kitessa Gutu
AU  - Tsegaab Tesfaye
AU  - Netsanet Bacha
AU  - Tamrat Negash
AU  - Daniel Kassa
AU  - Fikirte Yirga
AU  - Megersa Debela
AU  - Gudeta Bedada
AU  - Tesfaye Dessale
AU  - Ashenafi Gemechu
AU  - Tilahun Bayisa
AU  - Zerihun Eshetu
AU  - Zerihun Tomas
AU  - Girma Teshome
AU  - Mitiku Kebede
AU  - Bilal Temam
AU  - Misgana Mitiku
AU  - Bekele Kassa
AU  - Yitagesu Tadesse
AU  - Mequnanint Andualem
AU  - Tsehaye Brhane
AU  - Wulita Wondwosen
AU  - Nurhussen Seid
AU  - Zemedkun Alemu
Y1  - 2022/04/09
PY  - 2022
N1  - https://doi.org/10.11648/j.ajaf.20221002.15
DO  - 10.11648/j.ajaf.20221002.15
T2  - American Journal of Agriculture and Forestry
JF  - American Journal of Agriculture and Forestry
JO  - American Journal of Agriculture and Forestry
SP  - 72
EP  - 76
PB  - Science Publishing Group
SN  - 2330-8591
UR  - https://doi.org/10.11648/j.ajaf.20221002.15
AB  - Wheat stem rust caused by Puccinia graminis f.sp tritici is constant biotic constraint of wheat production across the world. Because of quick alteration of genetic makeup of wheat stem rust pathogen; monitoring shift in virulence within pathogen is crucial to avoid sudden occurrence of epidemics due race change. This study was to identify physiological races stem rust pathogen in Ethiopia during 2019 cropping season. Wheat stem rust samples were collected during 2019 main cropping season from major wheat growing areas of Oromia, Amhara, Tigray and Southern Nations Nationalities and Peoples regions of Ethiopia. Besides, samples were also collected from Afar region where wheat was grown by irrigation during off season. The samples where isolated on universally wheat stem rust susceptible line (McNair) for the sake of mono pustule isolation and multiplication to have sufficient spores. Each isolates where inoculated on twenty standard differential lines and each line was evaluated after fourteen days to determine the races. Eight stem rust races namely, TKKTF, TKTTF, TTTTF, TKKTT, TTKTT, TTRTF, TKPTF and TTKTF were identified from samples analyzed; TKKTF was identified from 175 (44.1%) stem rust isolates, while TTTTF was detected from 73 (18.4) samples analyzed. In addition, TKTTF was isolated from 70 (17.8%) samples; however, TTKTF, TTKTT, TTRTF, TKPTF and TKKTT were recorded from 48 (12.1%), 21 (5.3%), 4 (1%), 1 (0.25%) and 1 (0.25%) samples analyzed in the season. TTKTT races have 95% virulence spectra to stem rust resistance genes with in differential lines. Resistance genes (Sr24) that is available in most of commercial varieties worldwide became ineffective with these races. Therefore, breeding program should focus on searching for more sources of resistance to virulent races of the pathogen.
VL  - 10
IS  - 2
ER  -

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Author Information

Kitessa Gutu

Ethiopian Institute of Agricultural Research, Ambo Agricultural Research Center, Ambo, Ethiopia
Tsegaab Tesfaye

Ethiopian Institute of Agricultural Research, Ambo Agricultural Research Center, Ambo, Ethiopia
Netsanet Bacha

Ethiopian Institute of Agricultural Research, Ambo Agricultural Research Center, Ambo, Ethiopia
Tamrat Negash

Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Assela, Ethiopia
Daniel Kassa

Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Assela, Ethiopia
Fikirte Yirga

Ethiopian Institute of Agricultural Research, Kulumsa Agricultural Research Center, Assela, Ethiopia
Megersa Debela

Oromia Agricultural Research Institute, Bako Agricultural Research Center, Bako, Ethiopia
Gudeta Bedada

Oromia Agricultural Research Institute, Bako Agricultural Research Center, Bako, Ethiopia
Tesfaye Dessale

Amhara Region Agricultural Research Institute, Sirinka Agricultural Research Center, Wollo, Ethiopia
Ashenafi Gemechu

Ethiopian Institute of Agricultural Research, Debre Zeit Agricultural Research Center, Bishoftu, Ethiopia
Tilahun Bayisa

Oromia Agricultural Research Institute, Sinana Agricultural Research Center, Bale Robe, Ethiopia
Zerihun Eshetu

Oromia Agricultural Research Institute, Sinana Agricultural Research Center, Bale Robe, Ethiopia
Zerihun Tomas

Southern Agricultural Research Institute, Areka Agricultural Research Center, Areka, Ethiopia
Girma Teshome

Oromia Agricultural Research Institute, Bore Agricultural Research Center, Bore, Ethiopia
Mitiku Kebede

Southern Agricultural Research Institute, Werabe Agricultural Research Center, Werabe, Ethiopia
Bilal Temam

Southern Agricultural Research Institute, Werabe Agricultural Research Center, Werabe, Ethiopia
Misgana Mitiku

Southern Agricultural Research Institute, Werabe Agricultural Research Center, Werabe, Ethiopia
Bekele Kassa

Ethiopian Institute of Agricultural Research, Holetta Agricultural Research Center, Holeta, Ethiopia
Yitagesu Tadesse

Ethiopian Institute of Agricultural Research, Holetta Agricultural Research Center, Holeta, Ethiopia
Mequnanint Andualem

Amhara Region Agricultural Research Institute, Adet Agricultural Research Center, Adet, Ethiopia
Tsehaye Brhane

Tigray Agricultural Research Institute, Alamata Agricultural Research Center, Alamata, Ethiopia
Wulita Wondwosen

Amhara Region Agricultural Research Institute, Debrebirhan Agricultural Research Center, Debrebirhan, Ethiopia
Nurhussen Seid

Ethiopian Institute of Agricultural Research, Worer Agricultural Research Center, Worer, Ethiopia
Zemedkun Alemu

Ethiopian Institute of Agricultural Research, Worer Agricultural Research Center, Worer, Ethiopia

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APA Style

Kitessa Gutu, Tsegaab Tesfaye, Netsanet Bacha, Tamrat Negash, Daniel Kassa, et al. (2022). Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020. American Journal of Agriculture and Forestry, 10(2), 72-76. https://doi.org/10.11648/j.ajaf.20221002.15

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ACS Style

Kitessa Gutu; Tsegaab Tesfaye; Netsanet Bacha; Tamrat Negash; Daniel Kassa, et al. Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020. Am. J. Agric. For. 2022, 10(2), 72-76. doi: 10.11648/j.ajaf.20221002.15

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AMA Style

Kitessa Gutu, Tsegaab Tesfaye, Netsanet Bacha, Tamrat Negash, Daniel Kassa, et al. Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020. Am J Agric For. 2022;10(2):72-76. doi: 10.11648/j.ajaf.20221002.15

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@article{10.11648/j.ajaf.20221002.15,
  author = {Kitessa Gutu and Tsegaab Tesfaye and Netsanet Bacha and Tamrat Negash and Daniel Kassa and Fikirte Yirga and Megersa Debela and Gudeta Bedada and Tesfaye Dessale and Ashenafi Gemechu and Tilahun Bayisa and Zerihun Eshetu and Zerihun Tomas and Girma Teshome and Mitiku Kebede and Bilal Temam and Misgana Mitiku and Bekele Kassa and Yitagesu Tadesse and Mequnanint Andualem and Tsehaye Brhane and Wulita Wondwosen and Nurhussen Seid and Zemedkun Alemu},
  title = {Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020},
  journal = {American Journal of Agriculture and Forestry},
  volume = {10},
  number = {2},
  pages = {72-76},
  doi = {10.11648/j.ajaf.20221002.15},
  url = {https://doi.org/10.11648/j.ajaf.20221002.15},
  eprint = {https://article.sciencepublishinggroup.com/pdf/10.11648.j.ajaf.20221002.15},
  abstract = {Wheat stem rust caused by Puccinia graminis f.sp tritici is constant biotic constraint of wheat production across the world. Because of quick alteration of genetic makeup of wheat stem rust pathogen; monitoring shift in virulence within pathogen is crucial to avoid sudden occurrence of epidemics due race change. This study was to identify physiological races stem rust pathogen in Ethiopia during 2019 cropping season. Wheat stem rust samples were collected during 2019 main cropping season from major wheat growing areas of Oromia, Amhara, Tigray and Southern Nations Nationalities and Peoples regions of Ethiopia. Besides, samples were also collected from Afar region where wheat was grown by irrigation during off season. The samples where isolated on universally wheat stem rust susceptible line (McNair) for the sake of mono pustule isolation and multiplication to have sufficient spores. Each isolates where inoculated on twenty standard differential lines and each line was evaluated after fourteen days to determine the races. Eight stem rust races namely, TKKTF, TKTTF, TTTTF, TKKTT, TTKTT, TTRTF, TKPTF and TTKTF were identified from samples analyzed; TKKTF was identified from 175 (44.1%) stem rust isolates, while TTTTF was detected from 73 (18.4) samples analyzed. In addition, TKTTF was isolated from 70 (17.8%) samples; however, TTKTF, TTKTT, TTRTF, TKPTF and TKKTT were recorded from 48 (12.1%), 21 (5.3%), 4 (1%), 1 (0.25%) and 1 (0.25%) samples analyzed in the season. TTKTT races have 95% virulence spectra to stem rust resistance genes with in differential lines. Resistance genes (Sr24) that is available in most of commercial varieties worldwide became ineffective with these races. Therefore, breeding program should focus on searching for more sources of resistance to virulent races of the pathogen.},
 year = {2022}
}

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TY  - JOUR
T1  - Physiological Races of Puccinia graminis f. sp. tritici in Ethiopia in 2019/2020
AU  - Kitessa Gutu
AU  - Tsegaab Tesfaye
AU  - Netsanet Bacha
AU  - Tamrat Negash
AU  - Daniel Kassa
AU  - Fikirte Yirga
AU  - Megersa Debela
AU  - Gudeta Bedada
AU  - Tesfaye Dessale
AU  - Ashenafi Gemechu
AU  - Tilahun Bayisa
AU  - Zerihun Eshetu
AU  - Zerihun Tomas
AU  - Girma Teshome
AU  - Mitiku Kebede
AU  - Bilal Temam
AU  - Misgana Mitiku
AU  - Bekele Kassa
AU  - Yitagesu Tadesse
AU  - Mequnanint Andualem
AU  - Tsehaye Brhane
AU  - Wulita Wondwosen
AU  - Nurhussen Seid
AU  - Zemedkun Alemu
Y1  - 2022/04/09
PY  - 2022
N1  - https://doi.org/10.11648/j.ajaf.20221002.15
DO  - 10.11648/j.ajaf.20221002.15
T2  - American Journal of Agriculture and Forestry
JF  - American Journal of Agriculture and Forestry
JO  - American Journal of Agriculture and Forestry
SP  - 72
EP  - 76
PB  - Science Publishing Group
SN  - 2330-8591
UR  - https://doi.org/10.11648/j.ajaf.20221002.15
AB  - Wheat stem rust caused by Puccinia graminis f.sp tritici is constant biotic constraint of wheat production across the world. Because of quick alteration of genetic makeup of wheat stem rust pathogen; monitoring shift in virulence within pathogen is crucial to avoid sudden occurrence of epidemics due race change. This study was to identify physiological races stem rust pathogen in Ethiopia during 2019 cropping season. Wheat stem rust samples were collected during 2019 main cropping season from major wheat growing areas of Oromia, Amhara, Tigray and Southern Nations Nationalities and Peoples regions of Ethiopia. Besides, samples were also collected from Afar region where wheat was grown by irrigation during off season. The samples where isolated on universally wheat stem rust susceptible line (McNair) for the sake of mono pustule isolation and multiplication to have sufficient spores. Each isolates where inoculated on twenty standard differential lines and each line was evaluated after fourteen days to determine the races. Eight stem rust races namely, TKKTF, TKTTF, TTTTF, TKKTT, TTKTT, TTRTF, TKPTF and TTKTF were identified from samples analyzed; TKKTF was identified from 175 (44.1%) stem rust isolates, while TTTTF was detected from 73 (18.4) samples analyzed. In addition, TKTTF was isolated from 70 (17.8%) samples; however, TTKTF, TTKTT, TTRTF, TKPTF and TKKTT were recorded from 48 (12.1%), 21 (5.3%), 4 (1%), 1 (0.25%) and 1 (0.25%) samples analyzed in the season. TTKTT races have 95% virulence spectra to stem rust resistance genes with in differential lines. Resistance genes (Sr24) that is available in most of commercial varieties worldwide became ineffective with these races. Therefore, breeding program should focus on searching for more sources of resistance to virulent races of the pathogen.
VL  - 10
IS  - 2
ER  -

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