1
|
Vines PL, Hoffmann FG, Meyer F, Allen TW, Tomaso-Peterson M. Gaeumannomyces nanograminis, sp. nov., a hyphopodiate fungus identified from diseased roots of ultradwarf bermudagrass in the United States. Mycologia 2021; 113:938-948. [PMID: 34133260 DOI: 10.1080/00275514.2021.1911192] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/21/2022]
Abstract
The genus Gaeumannomyces (Magnaporthaceae, Magnaporthales, Sordariomycetes, Ascomycota) includes root-infecting pathogens, saprobes, and endophytes. Morphological, biological, and phylogenetic analyses were employed to identify fungal isolates derived from turfgrass roots colonized with ectotrophic, dark runner hyphae. Phylogenetic trees for partial sequences of the 18S nuc rDNA, ITS1-5.8S-ITS2 nuc rDNA internal transcribed spacer, and 28S nuc rDNA regions and of the minichromosome maintenance complex 7 (MCM7), largest subunit of RNA polymerase II (RPB1), and translation elongation factor 1-alpha (TEF1) genes were obtained via maximum likelihood and Bayesian methods. Our isolates consistently formed a distinct and highly supported clade within Gaeumannomyces. Common and distinctive biological and morphological characters reinforced these findings. Additionally, we conducted pathogenicity evaluations and demonstrated the ability of this fungus to colonize roots of ultradwarf bermudagrass (Cynodon dactylon (L.) Pers. × C. transvaalensis Burtt-Davey), its native host, via ectotrophic, dark runner hyphae, causing disease symptoms including root discoloration and reduced root and shoot mass. Altogether, our discoveries enabled recognition and description of a new species, Gaeumannomyces nanograminis, associated with rotted roots of ultradwarf bermudagrass.
Collapse
Affiliation(s)
- Phillip L Vines
- Department of Plant Biology, Rutgers University, New Brunswick, New Jersey 08901
| | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology, & Plant Pathology, Mississippi State University, Mississippi State, Mississippi 39762
| | - Florencia Meyer
- Department of Biochemistry, Molecular Biology, Entomology, & Plant Pathology, Mississippi State University, Mississippi State, Mississippi 39762
| | - Thomas W Allen
- Department of Biochemistry, Molecular Biology, Entomology, & Plant Pathology, Mississippi State University, Mississippi State, Mississippi 39762
| | - Maria Tomaso-Peterson
- Department of Biochemistry, Molecular Biology, Entomology, & Plant Pathology, Mississippi State University, Mississippi State, Mississippi 39762
| |
Collapse
|
2
|
Wang M, Ren X, Wang L, Lu X, Han L, Zhang X, Feng J. A functional analysis of mitochondrial respiratory chain cytochrome bc 1 complex in Gaeumannomyces tritici by RNA silencing as a possible target of carabrone. MOLECULAR PLANT PATHOLOGY 2020; 21:1529-1544. [PMID: 32997435 PMCID: PMC7694678 DOI: 10.1111/mpp.12993] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 08/20/2020] [Accepted: 08/21/2020] [Indexed: 05/05/2023]
Abstract
Gaeumannomyces tritici, an ascomycete soilborne fungus, causes a devastating root disease in wheat. Carabrone, a botanical bicyclic sesquiterpenic lactone, is a promising fungicidal agent that can effectively control G. tritici. However, the mechanism of action of carabrone against G. tritici remains largely unclear. Here, we used immunogold for subcellular localization of carabrone and the results showed that carabrone is subcellularly localized in the mitochondria of G. tritici. We then explored the functional analysis of genes GtCytc1 , GtCytb, and GtIsp of the mitochondrial respiratory chain cytochrome bc1 complex in G. tritici by RNA silencing as a possible target of carabrone. The results showed that the silenced mutant ∆GtIsp is less sensitive to carabrone compared to ∆GtCytc1 and ∆GtCytb. Compared with the control, the activities of complex III in all the strains, except ∆GtIsp and carabrone-resistant isolate 24-HN-1, were significantly decreased following treatment with carabrone at EC20 and EC80 in vitro (40%-50% and 70%-80%, respectively). The activities of mitochondrial respiratory chain complex III and the mitochondrial respiration oxygen consumption rates in all the strains, except ∆GtIsp and 24-HN-1, were higher with respect to the control when treated with carabrone at EC20 in vivo. The rates of mitochondrial respiration of all strains, except ∆GtIsp, were significantly inhibited following treatment with carabrone at EC80 (ranging from 57% to 81%). This study reveals that the targeting of the iron-sulphur protein encoded by GtIsp is highly sensitive to carabrone and provides a direction for the research of carabrone's target.
Collapse
Affiliation(s)
- Mei Wang
- Engineering and Research Center of Biological Pesticide of Shaanxi ProvinceNorthwest A&F UniversityYanglingChina
- College of Life SciencesYulin UniversityYulinChina
| | - Xingyu Ren
- Engineering and Research Center of Biological Pesticide of Shaanxi ProvinceNorthwest A&F UniversityYanglingChina
| | - Lanying Wang
- Engineering and Research Center of Biological Pesticide of Shaanxi ProvinceNorthwest A&F UniversityYanglingChina
- Key Laboratory of Green Prevention and Control of Tropical Plant Diseases and PestsMinistry of EducationHainan UniversityHaikouChina
| | - Xiang Lu
- Engineering and Research Center of Biological Pesticide of Shaanxi ProvinceNorthwest A&F UniversityYanglingChina
| | - Lirong Han
- Engineering and Research Center of Biological Pesticide of Shaanxi ProvinceNorthwest A&F UniversityYanglingChina
| | - Xing Zhang
- Engineering and Research Center of Biological Pesticide of Shaanxi ProvinceNorthwest A&F UniversityYanglingChina
- State Key Laboratory of Crop Stress Biology for Arid AreasNorthwest A&F UniversityYanglingChina
| | - Juntao Feng
- Engineering and Research Center of Biological Pesticide of Shaanxi ProvinceNorthwest A&F UniversityYanglingChina
- State Key Laboratory of Crop Stress Biology for Arid AreasNorthwest A&F UniversityYanglingChina
| |
Collapse
|
3
|
Stackhouse T, Martinez-Espinoza AD, Ali ME. Turfgrass Disease Diagnosis: Past, Present, and Future. PLANTS (BASEL, SWITZERLAND) 2020; 9:E1544. [PMID: 33187303 PMCID: PMC7697262 DOI: 10.3390/plants9111544] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/17/2020] [Revised: 10/30/2020] [Accepted: 11/09/2020] [Indexed: 01/15/2023]
Abstract
Turfgrass is a multibillion-dollar industry severely affected by plant pathogens including fungi, bacteria, viruses, and nematodes. Many of the diseases in turfgrass have similar signs and symptoms, making it difficult to diagnose the specific problem pathogen. Incorrect diagnosis leads to the delay of treatment and excessive use of chemicals. To effectively control these diseases, it is important to have rapid and accurate detection systems in the early stages of infection that harbor relatively low pathogen populations. There are many methods for diagnosing pathogens on turfgrass. Traditional methods include symptoms, morphology, and microscopy identification. These have been followed by nucleic acid detection and onsite detection techniques. Many of these methods allow for rapid diagnosis, some even within the field without much expertise. There are several methods that have great potential, such as high-throughput sequencing and remote sensing. Utilization of these techniques for disease diagnosis allows for faster and accurate disease diagnosis and a reduction in damage and cost of control. Understanding of each of these techniques can allow researchers to select which method is best suited for their pathogen of interest. The objective of this article is to provide an overview of the turfgrass diagnostics efforts used and highlight prospects for disease detection.
Collapse
Affiliation(s)
- Tammy Stackhouse
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA;
| | | | - Md Emran Ali
- Department of Plant Pathology, University of Georgia, Tifton, GA 31793, USA;
| |
Collapse
|
4
|
Marin-Felix Y, Hernández-Restrepo M, Wingfield M, Akulov A, Carnegie A, Cheewangkoon R, Gramaje D, Groenewald J, Guarnaccia V, Halleen F, Lombard L, Luangsa-ard J, Marincowitz S, Moslemi A, Mostert L, Quaedvlieg W, Schumacher R, Spies C, Thangavel R, Taylor P, Wilson A, Wingfield B, Wood A, Crous P. Genera of phytopathogenic fungi: GOPHY 2. Stud Mycol 2019; 92:47-133. [PMID: 29997401 PMCID: PMC6031069 DOI: 10.1016/j.simyco.2018.04.002] [Citation(s) in RCA: 80] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/01/2023] Open
Abstract
This paper represents the second contribution in the Genera of Phytopathogenic Fungi (GOPHY) series. The series provides morphological descriptions and information regarding the pathology, distribution, hosts and disease symptoms for the treated genera. In addition, primary and secondary DNA barcodes for the currently accepted species are included. This second paper in the GOPHY series treats 20 genera of phytopathogenic fungi and their relatives including: Allantophomopsiella, Apoharknessia, Cylindrocladiella, Diaporthe, Dichotomophthora, Gaeumannomyces, Harknessia, Huntiella, Macgarvieomyces, Metulocladosporiella, Microdochium, Oculimacula, Paraphoma, Phaeoacremonium, Phyllosticta, Proxypiricularia, Pyricularia, Stenocarpella, Utrechtiana and Wojnowiciella. This study includes the new genus Pyriculariomyces, 20 new species, five new combinations, and six typifications for older names.
Collapse
Key Words
- 26 new taxa
- Apoharknessia eucalypti Crous & M.J. Wingf.
- Cylindrocladiella addiensis L. Lombard & Crous
- Cylindrocladiella nauliensis L. Lombard & Crous
- DNA barcodes
- Diaporthe heterophyllae Guarnaccia & Crous
- Diaporthe racemosae A.R. Wood, Guarnaccia & Crous
- Dichotomophthora basellae Hern.-Restr., Cheew. & Crous
- Dichotomophthora brunnea Hern.-Restr. & Crous
- Fungal systematics
- Harknessia bourbonica Crous & M.J. Wingf.
- Harknessia corymbiae Crous & A.J. Carnegie
- Harknessia cupressi Crous & R.K. Schumach.
- Harknessia pilularis Crous & A.J. Carnegie
- Helminthosporium arundinaceum Corda
- Huntiella abstrusa A.M. Wilson, Marinc., M.J. Wingf.
- Macgarvieomyces luzulae (Ondřej) Y. Marín, Akulov & Crous
- Metulocladosporiella chiangmaiensis Y. Marín, Cheew. & Crous
- Metulocladosporiella malaysiana Y. Marín & Crous
- Metulocladosporiella musigena Y. Marín, Cheew. & Crous
- Metulocladosporiella samutensis Y. Marín, Luangsa-ard & Crous
- Microdochium novae-zelandiae Hern.-Restr., Thangavel & Crous
- Oculimacula acuformis (Nirenberg) Y. Marín & Crous
- Phaeoacremonium pravum C.F.J. Spies, L. Mostert & Halleen
- Phomopsis pseudotsugae M. Wilson
- Phyllosticta iridigena Y. Marín & Crous
- Phyllosticta persooniae Y. Marín & Crous
- Pyricularia luzulae Ondřej
- Pyricularia zingiberis Y. Nishik
- Pyriculariomyces Y. Marín, M.J. Wingf. & Crous
- Pyriculariomyces asari (Crous & M.J. Wingf.) Y. Marín, M.J. Wingf. & Crous
- Six new typifications
- Utrechtiana arundinacea (Corda) Crous, Quaedvl. & Y. Marín
- Utrechtiana constantinescui (Melnik & Shabunin) Crous & Y. Marín
Collapse
Affiliation(s)
- Y. Marin-Felix
- Westerdijk Fungal Biodiversity Institute, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, Pretoria, 0002, South Africa
| | - M. Hernández-Restrepo
- Westerdijk Fungal Biodiversity Institute, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
| | - M.J. Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, Pretoria, 0002, South Africa
| | - A. Akulov
- V.N. Karasin National University of Kharkiv, Svobody sq. 4, Kharkiv 61077, Ukraine
| | - A.J. Carnegie
- Forest Science, NSW Department of Primary Industries, Locked Bag 5123, Parramatta, New South Wales 2124, Australia
| | - R. Cheewangkoon
- Department of Plant Pathology, Faculty of Agriculture, Chiang Mai University, Chiang Mai 50200, Thailand
| | - D. Gramaje
- Instituto de Ciencias de la Vid y del Vino, Consejo Superior de Investigaciones Científicas, Universidad de la Rioja, Gobierno de La Rioja, 26071 Logroño, La Rioja, Spain
| | - J.Z. Groenewald
- Westerdijk Fungal Biodiversity Institute, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
| | - V. Guarnaccia
- Westerdijk Fungal Biodiversity Institute, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
| | - F. Halleen
- Department of Plant Pathology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
- Plant Protection Division, ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa
| | - L. Lombard
- Westerdijk Fungal Biodiversity Institute, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
| | - J. Luangsa-ard
- Microbe Interaction and Ecology Laboratory, Biodiversity and Biotechnological Resource Research Unit (BBR), BIOTEC, NSTDA 113, Thailand Science Park Phahonyothin Rd., Khlong Nueng, Khlong Luang, Pathum Thani 12120, Thailand
| | - S. Marincowitz
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, Pretoria, 0002, South Africa
| | - A. Moslemi
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne 3010, Melbourne, Victoria, Australia
| | - L. Mostert
- Department of Plant Pathology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
| | - W. Quaedvlieg
- Naktuinbouw, Sotaweg 22, 2371 GD Roelofarendsveen, the Netherlands
| | | | - C.F.J. Spies
- Department of Plant Pathology, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
- Plant Protection Division, ARC Infruitec-Nietvoorbij, Private Bag X5026, Stellenbosch 7599, South Africa
| | - R. Thangavel
- Plant Health and Environment Laboratory, Ministry for Primary Industries, P.O. Box 2095, Auckland 1140, New Zealand
| | - P.W.J. Taylor
- Faculty of Veterinary and Agricultural Sciences, University of Melbourne 3010, Melbourne, Victoria, Australia
| | - A.M. Wilson
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, Pretoria, 0002, South Africa
| | - B.D. Wingfield
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, Pretoria, 0002, South Africa
| | - A.R. Wood
- ARC – Plant Protection Research Institute, Private Bag X5017, Stellenbosch 7599, South Africa
| | - P.W. Crous
- Westerdijk Fungal Biodiversity Institute, P.O. Box 85167, 3508 AD Utrecht, The Netherlands
- Department of Biochemistry, Genetics and Microbiology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, P. Bag X20, Pretoria 0028, Pretoria, 0002, South Africa
- Wageningen University and Research Centre (WUR), Laboratory of Phytopathology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| |
Collapse
|
5
|
Wang M, Wang L, Han L, Zhang X, Feng J. The effect of carabrone on mitochondrial respiratory chain complexes inGaeumannomyces graminis. J Appl Microbiol 2017; 123:1100-1110. [DOI: 10.1111/jam.13554] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2016] [Revised: 07/07/2017] [Accepted: 07/27/2017] [Indexed: 01/01/2023]
Affiliation(s)
- M. Wang
- Research and Development Center of Biorational Pesticide; Northwest A&F University; Yangling 712100 Shaanxi China
| | - L. Wang
- Research and Development Center of Biorational Pesticide; Northwest A&F University; Yangling 712100 Shaanxi China
| | - L. Han
- Research and Development Center of Biorational Pesticide; Northwest A&F University; Yangling 712100 Shaanxi China
| | - X. Zhang
- Research and Development Center of Biorational Pesticide; Northwest A&F University; Yangling 712100 Shaanxi China
- Engineering and Research Center of Biological Pesticide of Shaanxi Province; Yangling 712100 Shaanxi China
| | - J. Feng
- Research and Development Center of Biorational Pesticide; Northwest A&F University; Yangling 712100 Shaanxi China
- Engineering and Research Center of Biological Pesticide of Shaanxi Province; Yangling 712100 Shaanxi China
| |
Collapse
|
6
|
Abstract
Take-all disease of Poaceae is caused by Gaeumannomyces graminis (Magnaporthaceae). Four varieties are recognised in G. graminis based on ascospore size, hyphopodial morphology and host preference. The aim of the present study was to clarify boundaries among species and varieties in Gaeumannomyces by combining morphology and multi-locus phylogenetic analyses based on partial gene sequences of ITS, LSU, tef1 and rpb1. Two new genera, Falciphoriella and Gaeumannomycella were subsequently introduced in Magnaporthaceae. The resulting phylogeny revealed several cryptic species previously overlooked within Gaeumannomyces. Isolates of Gaeumannomyces were distributed in four main clades, from which 19 species could be delimited, 12 of which were new to science. Our results show that the former varieties Gaeumannomyces graminis var. avenae and Gaeumannomyces graminis var. tritici represent species phylogenetically distinct from G. graminis, for which the new combinations G. avenae and G. tritici are introduced. Based on molecular data, morphology and host preferences, Gaeumannomyces graminis var. maydis is proposed as a synonym of G. radicicola. Furthermore, an epitype for Gaeumannomyces graminis var. avenae was designated to help stabilise the application of that name.
Collapse
Affiliation(s)
- M. Hernández-Restrepo
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa
| | - J.Z. Groenewald
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
| | - M.L. Elliott
- University of Florida – IFAS, Fort Lauderdale Research and Education Center, 3205 College Avenue, Fort Lauderdale (Davie), FL 33314, USA
| | - G. Canning
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
| | - V.E. McMillan
- Department of Plant Biology and Crop Science, Rothamsted Research, Harpenden, Herts AL5 2JQ, UK
| | - P.W. Crous
- CBS-KNAW Fungal Biodiversity Centre, Uppsalalaan 8, 3584 CT Utrecht, The Netherlands
- Department of Microbiology and Plant Pathology, Forestry and Agricultural Biotechnology Institute (FABI), University of Pretoria, Pretoria 0002, South Africa
- Microbiology, Department of Biology, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands
- Wageningen University and Research Centre (WUR), Laboratory of Phytopathology, Droevendaalsesteeg 1, 6708 PB Wageningen, The Netherlands
| |
Collapse
|
7
|
Kwak YS, Bakker PAHM, Glandorf DCM, Rice JT, Paulitz TC, Weller DM. Isolation, characterization, and sensitivity to 2,4-diacetylphloroglucinol of isolates of Phialophora spp. from Washington wheat fields. PHYTOPATHOLOGY 2010; 100:404-414. [PMID: 20373960 DOI: 10.1094/phyto-100-5-0404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
Dark pigmented fungi of the Gaeumannomyces-Phialophora complex were isolated from the roots of wheat grown in fields in eastern Washington State. These fungi were identified as Phialophora spp. on the basis of morphological and genetic characteristics. The isolates produced lobed hyphopodia on wheat coleoptiles, phialides, and hyaline phialospores. Sequence comparison of internal transcribed spacer regions indicated that the Phialophora isolates were clearly separated from other Gaeumannomyces spp. Primers AV1 and AV3 amplified 1.3-kb portions of an avenacinase-like gene in the Phialophora isolates. Phylogenetic trees of the avenacinase-like gene in the Phialophora spp. also clearly separated them from other Gaeumannomyces spp. The Phialophora isolates were moderately virulent on wheat and barley and produced confined black lesions on the roots of wild oat and two oat cultivars. Among isolates tested for their sensitivity to 2,4-diacetylphloroglucinol (2,4-DAPG), the 90% effective dose values were 11.9 to 48.2 microg ml(-1). A representative Phialophora isolate reduced the severity of take-all on wheat caused by two different isolates of Gaeumannomyces graminis var. tritici. To our knowledge, this study provides the first report of an avenacinase-like gene in Phialophora spp. and demonstrated that the fungus is significantly less sensitive to 2,4-DAPG than G. graminis var. tritici.
Collapse
Affiliation(s)
- Youn-Sig Kwak
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA
| | | | | | | | | | | |
Collapse
|
8
|
Kwak YS, Bakker PAHM, Glandorf DCM, Rice JT, Paulitz TC, Weller DM. Diversity, virulence, and 2,4-diacetylphloroglucinol sensitivity of Gaeumannomyces graminis var. tritici isolates from Washington state. PHYTOPATHOLOGY 2009; 99:472-479. [PMID: 19351242 DOI: 10.1094/phyto-99-5-0472] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
We determined whether isolates of the take-all pathogen Gaeumannomyces graminis var. tritici become less sensitive to 2,4-diacetylphloroglucinol (2,4-DAPG) during wheat monoculture as a result of exposure to the antibiotic over multiple growing seasons. Isolates of G. graminis var. tritici were baited from roots of native grasses collected from noncropped fields and from roots of wheat from fields with different cropping histories near Lind, Ritzville, Pullman, and Almota, WA. Isolates were characterized by using morphological traits, G. graminis variety-specific polymerase chain reaction and pathogenicity tests. The sensitivity of G. graminis var. tritici isolates to 2,4-DAPG was determined by measuring radial growth of each isolate. The 90% effective dose value was 3.1 to 4.4 microg ml(-1) for 2,4-DAPG-sensitive isolates, 4.5 to 6.1 microg ml(-1) for moderately sensitive isolates, and 6.2 to 11.1 microg ml(-1) for less sensitive isolates. Sensitivity of G. graminis var. tritici isolates to 2,4-DAPG was normally distributed in all fields and was not correlated with geographic origin or cropping history of the field. There was no correlation between virulence on wheat and geographical origin, or virulence and sensitivity to 2,4-DAPG. These results indicate that G. graminis var. tritici does not become less sensitive to 2,4-DAPG during extended wheat monoculture.
Collapse
Affiliation(s)
- Youn-Sig Kwak
- Department of Plant Pathology, Washington State University, Pullman, WA 99164-6430, USA
| | | | | | | | | | | |
Collapse
|
9
|
Tredway LP. Genetic Relationships Among Magnaporthe poae Isolates from Turfgrass Hosts and Relative Susceptibility of 'Penncross' and 'Penn A-4' Creeping Bentgrass. PLANT DISEASE 2006; 90:1531-1538. [PMID: 30780972 DOI: 10.1094/pd-90-1531] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Isolates of Magnaporthe poae from turfgrass hosts were analyzed for mating type, genetic relatedness according to ITS sequences, reaction to a previously developed species-specific poly-merase chain reaction (PCR) assay, and virulence on two creeping bentgrass cultivars in growth chamber experiments. Analysis of internal transcribed spacer (ITS) sequences revealed three clades, designated A, B, and C. Clade A contained isolates of both mating types from creeping bentgrass, annual bluegrass, and Kentucky bluegrass. Clade B contained only mating type 'A' isolates from annual bluegrass, whereas Clade C contained only mating type 'a' isolates from creeping bentgrass. The M. poae PCR assay failed to positively identify several North Carolina isolates from annual bluegrass and creeping bentgrass. M. poae isolates from Kentucky blue-grass were most virulent toward creeping bentgrass in growth chamber experiments. Although isolates of M. poae are not host specific, certain ITS clades may have a limited host or geographical range. The improved creeping bentgrass cv. Penn A-4 was more susceptible to summer patch than cv. Penncross. Additional research is needed to develop methods for accurate diagnosis of summer patch and other patch diseases in creeping bentgrass and to determine how creeping bentgrass cultivars vary in their susceptibility to these root pathogens.
Collapse
Affiliation(s)
- L P Tredway
- Department of Plant Pathology, North Carolina State University, Raleigh 27695
| |
Collapse
|
10
|
Thomas SL, Bonello P, Lipps PE, Boehm MJ. Avenacin Production in Creeping Bentgrass (Agrostis stolonifera) and Its Influence on the Host Range of Gaeumannomyces graminis. PLANT DISEASE 2006; 90:33-38. [PMID: 30786471 DOI: 10.1094/pd-90-0033] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Avenacinase activity has been shown to be a key factor determining the host range of Gaeumannomyces graminis on oats (Avena sativa). G. graminis var. avenae produces avenacinase, which detoxifies the oat root saponin avenacin, enabling it to infect oats. G. graminis var. tritici does not produce avenacinase and is unable to infect oats. G. graminis var. avenae is also reported to incite take-all patch on creeping bentgrass (Agrostis stolonifera). It is unknown whether creeping bentgrass produces avenacin and if the avenacin-avenacinase interaction influences G. graminis pathogenicity on creeping bentgrass. The root extracts of six creeping bentgrass cultivars were analyzed by fluorimetry, thin-layer chromatography, and high performance liquid chromatography for avenacin content. Avenacin was not detected in any creeping bentgrass cultivars, and pathogenicity assays confirmed that both G. graminis var. avenae and G. graminis var. tritici can infect creeping bentgrass and wheat (Triticum aestivum), but only G. graminis var. avenae incited disease on oats. These results are consistent with the root analyses and confirm that avenacinase activity is not required for creeping bentgrass infection by G. graminis.
Collapse
Affiliation(s)
- S L Thomas
- Department of Plant Pathology, The Ohio State University, Columbus 43210
| | - P Bonello
- Department of Plant Pathology, The Ohio State University, Columbus 43210
| | - P E Lipps
- Department of Plant Pathology, Ohio Agricultural Research and Development Center, The Ohio State University, Wooster 44691
| | - M J Boehm
- Department of Plant Pathology, The Ohio State University, Columbus
| |
Collapse
|
11
|
Kaminski JE, Dernoeden PH, O'Neill NR, Wetzel HC. A PCR-Based Method for the Detection of Ophiosphaerella agrostis in Creeping Bentgrass. PLANT DISEASE 2005; 89:980-985. [PMID: 30786632 DOI: 10.1094/pd-89-0980] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Dead spot is a relatively new disease of creeping bentgrass and hybrid bermudagrass that is incited by Ophiosphaerella agrostis. Initial symptoms are difficult to diagnose and clinicians generally rely on the presence of pseudothecia within infected tissue or isolation of O. agrostis on an artificial medium. The main goal of this study was to develop a polymerase chain reaction-based technique capable of quickly identifying O. agrostis within infected creeping bentgrass tissues. Oligonucleotide primers specific for O. agrostis were developed based on the internal transcribed spacer (ITS) rDNA regions (ITS1 and ITS2) of three previously sequenced isolates of O. agrostis. The 22-bp primers amplified a 445- or 446-bp region of 80 O. agrostis isolates collected from creeping bentgrass and bermudagrass in 11 states. Primers did not amplify DNA from other common turfgrass pathogens, including three closely related species of Ophiosphaerella. Selective amplification of O. agrostis was successful from field-infected creeping bent-grass samples and primers did not amplify the DNA of noninfected, field-grown creeping bent-grass or hybrid bermudagrass plants. Amplification of purified O. agrostis DNA was successful at quantities between 50 ng and 5 pg. The entire process, including DNA isolation, amplification, and amplicon visualization, may be completed within 4 h. These results indicate the specificity of these primers for assisting in the accurate and timely identification of O. agrostis and the diagnosis of dead spot in both bentgrass and bermudagrass hosts.
Collapse
Affiliation(s)
- John E Kaminski
- Department of Natural Resource Sciences and Landscape Architecture, University of Maryland, College Park 20742
| | - Peter H Dernoeden
- Department of Natural Resource Sciences and Landscape Architecture, University of Maryland, College Park 20742
| | - Nichole R O'Neill
- United States Department of Agriculture-Agricultural Research Service, Beltsville, MD 20705
| | | |
Collapse
|
12
|
Lebreton L, Lucas P, Dugas F, Guillerm AY, Schoeny A, Sarniguet A. Changes in population structure of the soilborne fungus Gaeumannomyces graminis var. tritici during continuous wheat cropping. Environ Microbiol 2004; 6:1174-85. [PMID: 15479250 DOI: 10.1111/j.1462-2920.2004.00637.x] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
A method was developed to assess the genetic structure of Gaeumannomyces graminis var. tritici (Ggt) populations and test the hypothesis of an association between disease level in the field with changes in pathogen populations. A long-term wheat monoculture experiment, established since 1994, generated different take-all epidemics with varying the number of wheat crop successions in the 1999-2000 cropping season. Genetic polymorphism in Ggt populations was investigated over natural, local epidemics. Four populations of 30 isolates were isolated from necrotic wheat roots in a first, third, fourth, and sixth wheat crop in the same year. Each Ggt isolate was characterized with RAPD (Random Amplification Polymorphism DNA) markers and AFLP (Amplified Fragment Length Polymorphism) fingerprinting. Seventeen multilocus genotypes based on the combination of RAPD and AFLP markers were identified among all these populations. The 120 isolates were divided into two main groups, G1 and G2, according to bootstrap values higher than 86%, except for an unique isolate from the third wheat crop. Within each group, populations ranged between 93 and 100% similarity. Both groups included isolates collected from the first, third, fourth or sixth wheat crop. However, G1 group profiles dominated amongst isolates sampled in the first and the sixth wheat crops, whereas G2 group profiles largely dominated amongst isolates collected from the third and fourth wheat crops. Aggressiveness of group G2 (38%) was significantly greater than that of G1 (29.5%). These results suggest that changes in Ggt population structure occur during continuous wheat cropping. The distinction of two Ggt groups provides a simple basis for further spatio-temporal analysis of Ggt population during polyetic take-all decline.
Collapse
Affiliation(s)
- Lionel Lebreton
- INRA UMR Biologie des Organismes et des Populations appliquée à la Protection des Plantes, Domaine de la Motte, BP 35327, F-35653 Le Rheu Cedex, France.
| | | | | | | | | | | |
Collapse
|
13
|
Freeman J, Ward E. Gaeumannomyces graminis, the take-all fungus and its relatives. MOLECULAR PLANT PATHOLOGY 2004; 5:235-252. [PMID: 20565593 DOI: 10.1111/j.1364-3703.2004.00226.x] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/29/2023]
Abstract
SUMMARY Take-all, caused by the fungus Gaeumannomyces graminis var. tritici, is the most important root disease of wheat worldwide. Many years of intensive research, reflected by the large volume of literature on take-all, has led to a considerable degree of understanding of many aspects of the disease. However, effective and economic control of the disease remains difficult. The application of molecular techniques to study G. graminis and related fungi has resulted in some significant advances, particularly in the development of improved methods for identification and in elucidating the role of the enzyme avenacinase as a pathogenicity determinant in the closely related oat take-all fungus (G. graminis var. avenae). Some progress in identifying other factors that may be involved in determining host range and pathogenicity has been made, despite the difficulties of performing genetic analyses and the lack of a reliable transformation system.
Collapse
Affiliation(s)
- Jacqueline Freeman
- Wheat Pathogenesis Programme, Plant-Pathogen Interactions Division, Rothamsted Research, Harpenden, Herts. AL5 2JQ, UK
| | | |
Collapse
|
14
|
Herdina, Neate S, Jabaji-Hare S, Ophel-Keller K. Persistence of DNA of Gaeumannomyces graminis var. tritici in soil as measured by a DNA-based assay. FEMS Microbiol Ecol 2004; 47:143-52. [DOI: 10.1016/s0168-6496(03)00255-1] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022] Open
|