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Mutiga SK, Orwa P, Nganga EM, Kyallo MM, Rotich F, Gichuhi E, Kimani JM, Mwongera DT, Were VM, Yanoria MJ, Murori R, Mgonja E, Ziyomo C, Wasilwa L, Bachabi F, Ndjiondjop MN, Ouedraogo I, Correll JC, Talbot NJ. Characterization of Blast Resistance in a Diverse Rice Panel from Sub-Saharan Africa. Phytopathology 2023; 113:1278-1288. [PMID: 36802875 DOI: 10.1094/phyto-10-22-0379-r] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
There is a recent unparalleled increase in demand for rice in sub-Saharan Africa, yet its production is affected by blast disease. Characterization of blast resistance in adapted African rice cultivars can provide important information to guide growers and rice breeders. We used molecular markers for known blast resistance genes (Pi genes; n = 21) to group African rice genotypes (n = 240) into similarity clusters. We then used greenhouse-based assays to challenge representative rice genotypes (n = 56) with African isolates (n = 8) of Magnaporthe oryzae which varied in virulence and genetic lineage. The markers grouped rice cultivars into five blast resistance clusters (BRC) which differed in foliar disease severity. Using stepwise regression, we found that the Pi genes associated with reduced blast severity were Pi50 and Pi65, whereas Pik-p, Piz-t, and Pik were associated with increased susceptibility. All rice genotypes in the most resistant cluster, BRC 4, possessed Pi50 and Pi65, the only genes that were significantly associated with reduced foliar blast severity. Cultivar IRAT109, which contains Piz-t, was resistant against seven African M. oryzae isolates, whereas ARICA 17 was susceptible to eight isolates. The popular Basmati 217 and Basmati 370 were among the most susceptible genotypes. These findings indicate that most tested genes were not effective against African blast pathogen collections. Pyramiding genes in the Pi2/9 multifamily blast resistance cluster on chromosome 6 and Pi65 on chromosome 11 could confer broad-spectrum resistance capabilities. To gain further insights into genomic regions associated with blast resistance, gene mapping could be conducted with resident blast pathogen collections. [Formula: see text] Copyright © 2023 The Author(s). This is an open access article distributed under the CC BY-NC-ND 4.0 International license.
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Affiliation(s)
- Samuel K Mutiga
- Biosciences for Eastern and Central Africa-International Livestock Research Institute, Nairobi, Kenya
- The University of Arkansas System-Division of Agriculture, Fayetteville, AR, U.S.A
| | | | | | - Martina M Kyallo
- Biosciences for Eastern and Central Africa-International Livestock Research Institute, Nairobi, Kenya
| | | | - Emily Gichuhi
- Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - John M Kimani
- Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - David T Mwongera
- Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | | | - Mary Jeanie Yanoria
- International Rice Research Institute (IRRI), Los Baños, Laguna, Philippines
| | | | | | - Cathrine Ziyomo
- Biosciences for Eastern and Central Africa-International Livestock Research Institute, Nairobi, Kenya
| | - Lusike Wasilwa
- Kenya Agricultural and Livestock Research Organization, Nairobi, Kenya
| | - Famata Bachabi
- Africa Rice Center (AfricaRice), Station de M'bé, Bouaké, Côte d'Ivoire
| | | | - Ibrahima Ouedraogo
- Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - James C Correll
- The University of Arkansas System-Division of Agriculture, Fayetteville, AR, U.S.A
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Nganga EM, Kyallo M, Orwa P, Rotich F, Gichuhi E, Kimani JM, Mwongera D, Waweru B, Sikuku P, Musyimi DM, Mutiga SK, Ziyomo C, Murori R, Wasilwa L, Correll JC, Talbot NJ. Foliar Diseases and the Associated Fungi in Rice Cultivated in Kenya. Plants 2022; 11:plants11091264. [PMID: 35567265 PMCID: PMC9105481 DOI: 10.3390/plants11091264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/04/2022] [Revised: 05/02/2022] [Accepted: 05/04/2022] [Indexed: 11/16/2022]
Abstract
We conducted a survey to assess the occurrence and severity of rice blast and brown spot diseases on popular cultivars grown in the Busia, Kirinyaga, and Kisumu counties of Kenya in 2019. Working with agricultural extension workers within rice production areas, we interviewed farmers (n = 89) regarding their preferred cultivars and their awareness of blast disease, as this was the major focus of our research. We scored the symptoms of blast and brown spot and assessed the lodging, plant height, and maturity of the crops (days after planting). Furthermore, we collected leaf and neck tissues for the assessment of the prevailing fungal populations. We used specific DNA primers to screen for the prevalence of the causal pathogens of blast, Magnaporthe oryzae, and brown spot, Cochliobolus miyabeanus, on asymptomatic and symptomatic leaf samples. We also conducted fungal isolations and PCR-sequencing to identify the fungal species in these tissues. Busia and Kisumu had a higher diversity of cultivars compared to Kirinyaga. The aromatic Pishori (NIBAM 11) was preferred and widely grown for commercial purposes in Kirinyaga, where 86% of Kenyan rice is produced. NIBAM108 (IR2793-80-1) and BW196 (NIBAM 109) were moderately resistant to blast, while NIBAM110 (ITA310) and Vietnam were susceptible. All the cultivars were susceptible to brown spot except for KEH10005 (Arize Tej Gold), a commercial hybrid cultivar. We also identified diverse pathogenic and non-pathogenic fungi, with a high incidence of Nigrospora oryzae, in the rice fields of Kirinyaga. There was a marginal correlation between disease severity/incidence and the occurrence of causal pathogens. This study provides evidence of the need to strengthen pathogen surveillance through retraining agricultural extension agents and to breed for blast and brown spot resistance in popular rice cultivars in Kenya.
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Affiliation(s)
- Everlyne M. Nganga
- Department of Botany, School of Physical and Biological Sciences, Maseno University, Kisumu P.O. Box 3275-40100, Kenya; (E.M.N.); (P.S.); (D.M.M.)
| | - Martina Kyallo
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Old Naivasha Road, Nairobi P.O. Box 30709-00100, Kenya; (M.K.); (B.W.); (C.Z.)
| | - Philemon Orwa
- Department of Water and Agricultural Resource Management, School of Agriculture, University of Embu, Embu P.O. Box 6-60100, Kenya; (P.O.); (F.R.)
| | - Felix Rotich
- Department of Water and Agricultural Resource Management, School of Agriculture, University of Embu, Embu P.O. Box 6-60100, Kenya; (P.O.); (F.R.)
| | - Emily Gichuhi
- Kenya Agricultural and Livestock Research Organization, Kaptagat Road, Loresho, Nairobi P.O. Box 57811-00200, Kenya; (E.G.); (J.M.K.); (D.M.); (L.W.)
| | - John M. Kimani
- Kenya Agricultural and Livestock Research Organization, Kaptagat Road, Loresho, Nairobi P.O. Box 57811-00200, Kenya; (E.G.); (J.M.K.); (D.M.); (L.W.)
| | - David Mwongera
- Kenya Agricultural and Livestock Research Organization, Kaptagat Road, Loresho, Nairobi P.O. Box 57811-00200, Kenya; (E.G.); (J.M.K.); (D.M.); (L.W.)
| | - Bernice Waweru
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Old Naivasha Road, Nairobi P.O. Box 30709-00100, Kenya; (M.K.); (B.W.); (C.Z.)
| | - Phoebe Sikuku
- Department of Botany, School of Physical and Biological Sciences, Maseno University, Kisumu P.O. Box 3275-40100, Kenya; (E.M.N.); (P.S.); (D.M.M.)
| | - David M. Musyimi
- Department of Botany, School of Physical and Biological Sciences, Maseno University, Kisumu P.O. Box 3275-40100, Kenya; (E.M.N.); (P.S.); (D.M.M.)
| | - Samuel K. Mutiga
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Old Naivasha Road, Nairobi P.O. Box 30709-00100, Kenya; (M.K.); (B.W.); (C.Z.)
- Eastern and Southern Region Office, International Rice Research Institute, ILRI Complex, Old Naivasha Road, Nairobi P.O. Box 30709-00100, Kenya;
- Correspondence:
| | - Cathrine Ziyomo
- Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Old Naivasha Road, Nairobi P.O. Box 30709-00100, Kenya; (M.K.); (B.W.); (C.Z.)
| | - Rosemary Murori
- Department of Entomology and Plant Pathology, Division of Agriculture, The University of Arkansas System, Fayetteville, AR 72701, USA;
| | - Lusike Wasilwa
- Kenya Agricultural and Livestock Research Organization, Kaptagat Road, Loresho, Nairobi P.O. Box 57811-00200, Kenya; (E.G.); (J.M.K.); (D.M.); (L.W.)
| | - James C. Correll
- Eastern and Southern Region Office, International Rice Research Institute, ILRI Complex, Old Naivasha Road, Nairobi P.O. Box 30709-00100, Kenya;
| | - Nicholas J. Talbot
- The Sainsbury Laboratory, Norwich Research Park, University of East Anglia, Norwich NR4 7UH, UK;
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Mutiga SK, Rotich F, Were VM, Kimani JM, Mwongera DT, Mgonja E, Onaga G, Konaté K, Razanaboahirana C, Bigirimana J, Ndayiragije A, Gichuhi E, Yanoria MJ, Otipa M, Wasilwa L, Ouedraogo I, Mitchell T, Wang GL, Correll JC, Talbot NJ. Integrated Strategies for Durable Rice Blast Resistance in Sub-Saharan Africa. Plant Dis 2021; 105:2749-2770. [PMID: 34253045 DOI: 10.1094/pdis-03-21-0593-fe] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
Rice is a key food security crop in Africa. The importance of rice has led to increasing country-specific, regional, and multinational efforts to develop germplasm and policy initiatives to boost production for a more food-secure continent. Currently, this critically important cereal crop is predominantly cultivated by small-scale farmers under suboptimal conditions in most parts of sub-Saharan Africa (SSA). Rice blast disease, caused by the fungus Magnaporthe oryzae, represents one of the major biotic constraints to rice production under small-scale farming systems of Africa, and developing durable disease resistance is therefore of critical importance. In this review, we provide an overview of the major advances by a multinational collaborative research effort to enhance sustainable rice production across SSA and how it is affected by advances in regional policy. As part of the multinational effort, we highlight the importance of joint international partnerships in tackling multiple crop production constraints through integrated research and outreach programs. More specifically, we highlight recent progress in establishing international networks for rice blast disease surveillance, farmer engagement, monitoring pathogen virulence spectra, and the establishment of regionally based blast resistance breeding programs. To develop blast-resistant, high yielding rice varieties for Africa, we have established a breeding pipeline that utilizes real-time data of pathogen diversity and virulence spectra, to identify major and minor blast resistance genes for introgression into locally adapted rice cultivars. In addition, the project has developed a package to support sustainable rice production through regular stakeholder engagement, training of agricultural extension officers, and establishment of plant clinics.
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Affiliation(s)
- Samuel K Mutiga
- Biosciences eastern and central Africa - International Livestock Research Institute (BecA-ILRI), Nairobi, Kenya
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR 72701, U.S.A
| | - Felix Rotich
- Department of Agricultural Resource Management, University of Embu, Embu, Kenya
| | - Vincent M Were
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, U.K
| | - John M Kimani
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - David T Mwongera
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | | | - Geoffrey Onaga
- National Agricultural Research Organization, Kampala, Uganda
| | - Kadougoudiou Konaté
- Institute of Environment and Agricultural Research, Bobo-Dioulasso, Burkina Faso
| | | | | | | | - Emily Gichuhi
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | | | - Miriam Otipa
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - Lusike Wasilwa
- Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya
| | - Ibrahima Ouedraogo
- Institute of Environment and Agricultural Research, Bobo-Dioulasso, Burkina Faso
| | - Thomas Mitchell
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
| | - Guo-Liang Wang
- Department of Plant Pathology, The Ohio State University, Columbus, OH 43210, U.S.A
| | - James C Correll
- Department of Entomology and Plant Pathology, University of Arkansas, Fayetteville, AR 72701, U.S.A
| | - Nicholas J Talbot
- The Sainsbury Laboratory, University of East Anglia, Norwich NR4 7UH, U.K
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Mutiga SK, Mutuku JM, Koskei V, Gitau JK, Ng’ang’a F, Musyoka J, Chemining’wa GN, Murori R. Multiple Mycotoxins in Kenyan Rice. Toxins (Basel) 2021; 13:toxins13030203. [PMID: 33799626 PMCID: PMC7998506 DOI: 10.3390/toxins13030203] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2021] [Revised: 02/20/2021] [Accepted: 02/23/2021] [Indexed: 11/16/2022] Open
Abstract
Multiple mycotoxins were tested in milled rice samples (n = 200) from traders at different milling points within the Mwea Irrigation Scheme in Kenya. Traders provided the names of the cultivar, village where paddy was cultivated, sampling locality, miller, and month of paddy harvest between 2018 and 2019. Aflatoxin, citrinin, fumonisin, ochratoxin A, diacetoxyscirpenol, T2, HT2, and sterigmatocystin were analyzed using ultra-high-performance liquid chromatography–tandem mass spectrometry (UHPLC–MS/MS). Deoxynivalenol was tested using enzyme-linked immunosorbent assay (ELISA). Mycotoxins occurred in ranges and frequencies in the following order: sterigmatocystin (0–7 ppb; 74.5%), aflatoxin (0–993 ppb; 55.5%), citrinin (0–9 ppb; 55.5%), ochratoxin A (0–110 ppb; 30%), fumonisin (0–76 ppb; 26%), diacetoxyscirpenol (0–24 ppb; 20.5%), and combined HT2 + T2 (0–62 ppb; 14.5%), and deoxynivalenol was detected in only one sample at 510 ppb. Overall, low amounts of toxins were observed in rice with a low frequency of samples above the regulatory limits for aflatoxin, 13.5%; ochratoxin A, 6%; and HT2 + T2, 0.5%. The maximum co-contamination was for 3.5% samples with six toxins in different combinations. The rice cultivar, paddy environment, time of harvest, and millers influenced the occurrence of different mycotoxins. There is a need to establish integrated approaches for the mitigation of mycotoxin accumulation in the Kenyan rice.
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Affiliation(s)
- Samuel K. Mutiga
- Biosciences Eastern and Central Africa, International Livestock Research Institute (BecA-ILRI) Hub, P.O. BOX 30709, 00100 Nairobi, Kenya; (J.M.M.); (F.N.); (J.M.)
- Department of Entomology & Plant Pathology, University of Arkansas, Fayetteville, AR 72701, USA
- Correspondence: (S.K.M.); (R.M.)
| | - J. Musembi Mutuku
- Biosciences Eastern and Central Africa, International Livestock Research Institute (BecA-ILRI) Hub, P.O. BOX 30709, 00100 Nairobi, Kenya; (J.M.M.); (F.N.); (J.M.)
| | - Vincent Koskei
- National Irrigation Authority (NIA), P.O. Box 210, 10303 Wang’uru, Kenya;
| | - James Kamau Gitau
- Department of Plant Science and Crop Protection, University of Nairobi, P.O. BOX 29053, 00625 Nairobi, Kenya; (J.K.G.); (G.N.C.)
| | - Fredrick Ng’ang’a
- Biosciences Eastern and Central Africa, International Livestock Research Institute (BecA-ILRI) Hub, P.O. BOX 30709, 00100 Nairobi, Kenya; (J.M.M.); (F.N.); (J.M.)
| | - Joyce Musyoka
- Biosciences Eastern and Central Africa, International Livestock Research Institute (BecA-ILRI) Hub, P.O. BOX 30709, 00100 Nairobi, Kenya; (J.M.M.); (F.N.); (J.M.)
| | - George N. Chemining’wa
- Department of Plant Science and Crop Protection, University of Nairobi, P.O. BOX 29053, 00625 Nairobi, Kenya; (J.K.G.); (G.N.C.)
| | - Rosemary Murori
- International Rice Research Institute, Eastern and Southern African Region Office, P.O. BOX 30709, 00100 Nairobi, Kenya
- Correspondence: (S.K.M.); (R.M.)
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Mgonja EM, Park CH, Kang H, Balimponya EG, Opiyo S, Bellizzi M, Mutiga SK, Rotich F, Ganeshan VD, Mabagala R, Sneller C, Correll J, Zhou B, Talbot NJ, Mitchell TK, Wang GL. Genotyping-by-Sequencing-Based Genetic Analysis of African Rice Cultivars and Association Mapping of Blast Resistance Genes Against Magnaporthe oryzae Populations in Africa. Phytopathology 2017; 107:1039-1046. [PMID: 28719243 DOI: 10.1094/phyto-12-16-0421-r] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/07/2023]
Abstract
Understanding the genetic diversity of rice germplasm is important for the sustainable use of genetic materials in rice breeding and production. Africa is rich in rice genetic resources that can be utilized to boost rice productivity on the continent. A major constraint to rice production in Africa is rice blast, caused by the hemibiotrophic fungal pathogen Magnaporthe oryzae. In this report, we present the results of a genotyping-by-sequencing (GBS)-based diversity analysis of 190 African rice cultivars and an association mapping of blast resistance (R) genes and quantitative trait loci (QTLs). The 190 African cultivars were clustered into three groups based on the 184K single nucleotide polymorphisms generated by GBS. We inoculated the rice cultivars with six African M. oryzae isolates. Association mapping identified 25 genomic regions associated with blast resistance (RABRs) in the rice genome. Moreover, PCR analysis indicated that RABR_23 is associated with the Pi-ta gene on chromosome 12. Our study demonstrates that the combination of GBS-based genetic diversity population analysis and association mapping is effective in identifying rice blast R genes/QTLs that contribute to resistance against African populations of M. oryzae. The identified markers linked to the RABRs and 14 highly resistant cultivars in this study will be useful for rice breeding in Africa.
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Affiliation(s)
- Emmanuel M Mgonja
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Chan Ho Park
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Houxiang Kang
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Elias G Balimponya
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Stephen Opiyo
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Maria Bellizzi
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Samuel K Mutiga
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Felix Rotich
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Veena Devi Ganeshan
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Robert Mabagala
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Clay Sneller
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Jim Correll
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Bo Zhou
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Nicholas J Talbot
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Thomas K Mitchell
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
| | - Guo-Liang Wang
- First, second, fifth, sixth, ninth, fifteenth, and sixteenth authors: Department of Plant Pathology, The Ohio State University, Columbus; fourth and eleventh authors: Department of Horticulture and Crop science, The Ohio State University, Columbus; third author: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing, China; tenth author: Department of Crop Science and Production, Sokoine University of Agriculture, Morogoro, Tanzania; seventh, eighth, and twelfth author: Department of Plant Pathology, University of Arkansas, Fayetteville; seventh author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, ILRI Complex, Nairobi, Kenya; thirteenth author: International Rice Research Institute, Los Banos, Philippines; and fourteenth author, School of Biosciences, University of Exeter, UK
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Mutiga SK, Rotich F, Ganeshan VD, Mwongera DT, Mgonja EM, Were VM, Harvey JW, Zhou B, Wasilwa L, Feng C, Ouédraogo I, Wang GL, Mitchell TK, Talbot NJ, Correll JC. Assessment of the Virulence Spectrum and Its Association with Genetic Diversity in Magnaporthe oryzae Populations from Sub-Saharan Africa. Phytopathology 2017; 107:852-863. [PMID: 28368237 DOI: 10.1094/phyto-08-16-0319-r] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
A collection of 122 isolates of Magnaporthe oryzae, from nine sub-Saharan African countries, was assessed for virulence diversity and genetic relatedness. The virulence spectrum was assessed by pathotype analysis with a panel of 43 rice genotypes consisting of differential lines carrying 24 blast resistance genes (R-genes), contemporary African rice cultivars, and susceptible checks. The virulence spectrum among isolates ranged from 5 to 80%. Five isolates were avirulent to the entire rice panel, while two isolates were virulent to ∼75% of the panel. Overall, cultivar 75-1-127, the Pi9 R-gene donor, was resistant to all isolates (100%), followed by four African rice cultivars (AR105, NERICA 15, 96%; NERICA 4, 91%; and F6-36, 90%). Genetic relatedness of isolates was assessed by single nucleotide polymorphisms derived from genotyping-by-sequencing and by vegetative compatibility tests. Phylogenetic analysis of SNPs of a subset of isolates (n = 78) revealed seven distinct clades that differed in virulence. Principal component analysis showed isolates from East Africa were genetically distinct from those from West Africa. Vegetative compatibility tests of a subset of isolates (n = 65) showed no common groups among countries. This study shows that blast disease could be controlled by pyramiding of Pi9 together with other promising R-genes into rice cultivars that are adapted to East and West African regions.
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Affiliation(s)
- S K Mutiga
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - F Rotich
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - V Devi Ganeshan
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - D T Mwongera
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - E M Mgonja
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - V M Were
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - J W Harvey
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - B Zhou
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - L Wasilwa
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - C Feng
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - I Ouédraogo
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - G-L Wang
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - T K Mitchell
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - N J Talbot
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
| | - J C Correll
- First, second, tenth, and fifteenth authors: Department of Plant Pathology, University of Arkansas-Fayetteville; first and seventh: Biosciences eastern and central Africa-International Livestock Research Institute (BecA-ILRI) Hub, Nairobi, Kenya; third, fifth, twelfth, and thirteenth authors: Department of Plant Pathology, The Ohio State University-Columbus; fourth, sixth, and fourteenth authors: Biosciences department, Exeter University, UK; seventh author: Feed the Future Innovation Lab for the Reduction of Post-Harvest Loss, Kansas State University, Manhattan, Kansas; eighth author: International Rice Research Institute (IRRI), Philippines; ninth author: Kenya Agricultural and Livestock Research Organization (KALRO), Nairobi, Kenya; and eleventh author: Institute of Environment and Agricultural Research, Ouagadougou, Burkina Faso
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Mutiga SK, Hoffmann V, Harvey JW, Milgroom MG, Nelson RJ. Assessment of Aflatoxin and Fumonisin Contamination of Maize in Western Kenya. Phytopathology 2015; 105:1250-1261. [PMID: 25894319 DOI: 10.1094/phyto-10-14-0269-r] [Citation(s) in RCA: 47] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
We conducted a survey of aflatoxin and fumonisin in maize in western Kenya. In a regional survey of aflatoxin conducted in 2009 across three agroecological zones within three administrative regions, milled maize samples were collected from 985 patrons of 26 hammer mills. Aflatoxin contamination was detected in 49% of samples and was above the regulatory (10 ppb) in 15% of the samples overall; 65% of samples from a drought-prone area were over the limit. In a detailed survey in Bungoma County, we investigated aflatoxin and fumonisin contamination in four popular maize varieties at harvest and after 2 and 4 months of storage. We collected whole-grain samples from farmers' storage sheds and milled samples from patrons of local mills. Mean aflatoxin contamination was identical for storage sheds and mills at 2.3 ppb. In all, 41% of the samples from mills had detectable aflatoxin, with 4% over the regulatory limit, whereas 87% had detectable fumonisin, with 50% over the regulatory limit (1 ppm). Mean contamination levels did not change during storage. Maize varieties differed in fumonisin contamination, with the most popular varieties vulnerable to both mycotoxins and weevils, which are potential factors in exacerbating mycotoxin contamination. Mycotoxin surveillance is important not just in areas known previously for aflatoxin contamination and acute poisoning but also is needed in all maize-producing regions.
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Affiliation(s)
- S K Mutiga
- First, fourth, and fifth authors: School of Integrative Plant Science, Section of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853; second author: International Food Policy Research Institute, 2033 K Street NW, Washington DC 20006; and third author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi 00100, Kenya
| | - V Hoffmann
- First, fourth, and fifth authors: School of Integrative Plant Science, Section of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853; second author: International Food Policy Research Institute, 2033 K Street NW, Washington DC 20006; and third author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi 00100, Kenya
| | - J W Harvey
- First, fourth, and fifth authors: School of Integrative Plant Science, Section of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853; second author: International Food Policy Research Institute, 2033 K Street NW, Washington DC 20006; and third author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi 00100, Kenya
| | - M G Milgroom
- First, fourth, and fifth authors: School of Integrative Plant Science, Section of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853; second author: International Food Policy Research Institute, 2033 K Street NW, Washington DC 20006; and third author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi 00100, Kenya
| | - R J Nelson
- First, fourth, and fifth authors: School of Integrative Plant Science, Section of Plant Pathology and Plant-Microbe Biology, Cornell University, Ithaca, NY 14853; second author: International Food Policy Research Institute, 2033 K Street NW, Washington DC 20006; and third author: Biosciences Eastern and Central Africa-International Livestock Research Institute (BecA-ILRI) Hub, P.O. Box 30709, Nairobi 00100, Kenya
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Mutiga SK, Were V, Hoffmann V, Harvey JW, Milgroom MG, Nelson RJ. Extent and drivers of mycotoxin contamination: inferences from a survey of kenyan maize mills. Phytopathology 2014; 104:1221-1231. [PMID: 24835222 DOI: 10.1094/phyto-01-14-0006-r] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The prevalence of aflatoxin and fumonisin was investigated in maize intended for immediate human consumption in eastern Kenya at a time in 2010 when an aflatoxin outbreak was recognized. Samples were collected from people who brought their maize for processing at local commercial mills. Sites were selected using a geographical information system overlay of agroecological zones and Kenya's administrative districts. Interviews and collection of maize flour samples was conducted from 1,500 people who processed maize at 143 mills in 10 administrative districts. Mycotoxins were analyzed using enzyme-linked immunosorbent assays for aflatoxin and fumonisin, leading to detection at levels above the respective maximum tolerable limits in 39 and 37% of the samples, respectively. Samples with aflatoxin contamination above the legal limit ranged between 22 and 60% across the districts. A higher occurrence of aflatoxin was associated with smaller maize farms, lower grain yield, and monocropping systems, while a larger magnitude of the toxin was observed in the subhumid agroecological zone, in samples with more broken kernels, and, curiously, less maize ear damage at harvest. Analysis of paired grain samples (visually sorted and unsorted) showed that sorting reduced fumonisin by 65%, from above to below the legal limit of 1,000 ppb. Sorting did not, however, reduce aflatoxin levels. Although the aflatoxin problem is widely acknowledged, the high prevalence of fumonisin has not previously been reported. There is need for surveillance of the two mycotoxins and establishment of intervention strategies to reach vulnerable small-scale farmers.
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