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Nallathambi P, Umamaheswari C, Reddy B, Aarthy B, Javed M, Ravikumar P, Watpade S, Kashyap PL, Boopalakrishnan G, Kumar S, Sharma A, Kumar A. Deciphering the Genomic Landscape and Virulence Mechanisms of the Wheat Powdery Mildew Pathogen Blumeria graminis f. sp. tritici Wtn1: Insights from Integrated Genome Assembly and Conidial Transcriptomics. J Fungi (Basel) 2024; 10:267. [PMID: 38667938 PMCID: PMC11051031 DOI: 10.3390/jof10040267] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 03/16/2024] [Accepted: 03/19/2024] [Indexed: 04/28/2024] Open
Abstract
A high-quality genome sequence from an Indian isolate of Blumeria graminis f. sp. tritici Wtn1, a persistent threat in wheat farming, was obtained using a hybrid method. The assembly of over 9.24 million DNA-sequence reads resulted in 93 contigs, totaling a 140.61 Mb genome size, potentially encoding 8480 genes. Notably, more than 73.80% of the genome, spanning approximately 102.14 Mb, comprises retro-elements, LTR elements, and P elements, influencing evolution and adaptation significantly. The phylogenomic analysis placed B. graminis f. sp. tritici Wtn1 in a distinct monocot-infecting clade. A total of 583 tRNA anticodon sequences were identified from the whole genome of the native virulent strain B. graminis f. sp. tritici, which comprises distinct genome features with high counts of tRNA anticodons for leucine (70), cysteine (61), alanine (58), and arginine (45), with only two stop codons (Opal and Ochre) present and the absence of the Amber stop codon. Comparative InterProScan analysis unveiled "shared and unique" proteins in B. graminis f. sp. tritici Wtn1. Identified were 7707 protein-encoding genes, annotated to different categories such as 805 effectors, 156 CAZymes, 6102 orthologous proteins, and 3180 distinct protein families (PFAMs). Among the effectors, genes like Avra10, Avrk1, Bcg-7, BEC1005, CSEP0105, CSEP0162, BEC1016, BEC1040, and HopI1 closely linked to pathogenesis and virulence were recognized. Transcriptome analysis highlighted abundant proteins associated with RNA processing and modification, post-translational modification, protein turnover, chaperones, and signal transduction. Examining the Environmental Information Processing Pathways in B. graminis f. sp. tritici Wtn1 revealed 393 genes across 33 signal transduction pathways. The key pathways included yeast MAPK signaling (53 genes), mTOR signaling (38 genes), PI3K-Akt signaling (23 genes), and AMPK signaling (21 genes). Additionally, pathways like FoxO, Phosphatidylinositol, the two-component system, and Ras signaling showed significant gene representation, each with 15-16 genes, key SNPs, and Indels in specific chromosomes highlighting their relevance to environmental responses and pathotype evolution. The SNP and InDel analysis resulted in about 3.56 million variants, including 3.45 million SNPs, 5050 insertions, and 5651 deletions within the whole genome of B. graminis f. sp. tritici Wtn1. These comprehensive genome and transcriptome datasets serve as crucial resources for understanding the pathogenicity, virulence effectors, retro-elements, and evolutionary origins of B. graminis f. sp. tritici Wtn1, aiding in developing robust strategies for the effective management of wheat powdery mildew.
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Affiliation(s)
- Perumal Nallathambi
- ICAR-Indian Agricultural Research Institute, Regional Station, Wellington 643231, Tamil Nadu, India; (P.N.); (C.U.); (B.A.); (P.R.)
| | - Chandrasekaran Umamaheswari
- ICAR-Indian Agricultural Research Institute, Regional Station, Wellington 643231, Tamil Nadu, India; (P.N.); (C.U.); (B.A.); (P.R.)
| | - Bhaskar Reddy
- ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi 110012, Delhi, India; (M.J.); (G.B.)
| | - Balakrishnan Aarthy
- ICAR-Indian Agricultural Research Institute, Regional Station, Wellington 643231, Tamil Nadu, India; (P.N.); (C.U.); (B.A.); (P.R.)
| | - Mohammed Javed
- ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi 110012, Delhi, India; (M.J.); (G.B.)
| | - Priya Ravikumar
- ICAR-Indian Agricultural Research Institute, Regional Station, Wellington 643231, Tamil Nadu, India; (P.N.); (C.U.); (B.A.); (P.R.)
| | - Santosh Watpade
- ICAR-Indian Agricultural Research Institute, Regional Station, Shimla 171004, Himachal Pradesh, India;
| | - Prem Lal Kashyap
- ICAR-Indian Institute of Wheat and Barley Research, Karnal 132001, Haryana, India; (P.L.K.); (S.K.); (A.S.)
| | | | - Sudheer Kumar
- ICAR-Indian Institute of Wheat and Barley Research, Karnal 132001, Haryana, India; (P.L.K.); (S.K.); (A.S.)
| | - Anju Sharma
- ICAR-Indian Institute of Wheat and Barley Research, Karnal 132001, Haryana, India; (P.L.K.); (S.K.); (A.S.)
| | - Aundy Kumar
- ICAR-Indian Agricultural Research Institute, Pusa Campus, New Delhi 110012, Delhi, India; (M.J.); (G.B.)
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Darshan K, Aggarwal R, Bashyal BM, Singh J, Saharan MS, Gurjar MS, Solanke AU. Characterization and development of transcriptome-derived novel EST-SSR markers to assess genetic diversity in Chaetomium globosum. 3 Biotech 2023; 13:379. [PMID: 37900266 PMCID: PMC10600081 DOI: 10.1007/s13205-023-03794-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2022] [Accepted: 09/25/2023] [Indexed: 10/31/2023] Open
Abstract
Chaetomium globosum Kunze, an internationally recognized biocontrol fungus. It mycoparasitizes various plant pathogens and produce antifungal metabolites to suppress the growth of pathogenic fungi. Lack of detailed genome level diversity studies has delimited the development and utilization of potential C. globosum strains. The present study was taken to reveal the distribution, identification, and characterization of expressed sequence tag-simple sequence repeats (EST-SSRs) in C. globosum. RNA-Seq experiment was performed for C. globosum potential isolate Cg2 (AY429049) using Illumina HiSeq 2500. Reference-guided de novo assembly yielded 45,582 transcripts containing 27,957 unigenes. We generated a new set of 8485 EST-SSR markers distributed in 5908 unigene sequences with one SSR locus distribution density per 6.1 kb. Six distinct classes of SSR repeat motifs were identified. The most abundant were mononucleotide repeats (51.67%), followed by tri-nucleotides (36.61%). Out of 5034 EST-SSR primers, 50 primer pairs were selected and validated for the polymorphic study of 15 C. globosum isolates. Twenty-two SSR markers showed average genetic polymorphism among C. globosum isolates. The number of alleles (Na) per marker ranges from 2 to 4, with a total of 74 alleles detected for 22 markers with a mean polymorphism information content (PIC) value of 0.4. UPGMA hierarchical clustering analysis generated three main clusters of C. globosum isolates and exhibited a lower similarity index range from 0.59 to 0.85. Thus, the newly developed EST-SSR markers could replace traditional methods for determining diversity. The study will also enhance the genomic research in C. globosum to explore its biocontrol potential against phytopathogens. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-023-03794-7.
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Affiliation(s)
- K. Darshan
- Division of Plant Pathology, Fungal Molecular Biology Laboratory, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
- Forest Protection Division, ICFRE-Tropical Forest Research Institute, Jabalpur, Madhya Pradesh 482021 India
| | - Rashmi Aggarwal
- Division of Plant Pathology, Fungal Molecular Biology Laboratory, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Bishnu Maya Bashyal
- Division of Plant Pathology, Fungal Molecular Biology Laboratory, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Jagmohan Singh
- Division of Plant Pathology, Fungal Molecular Biology Laboratory, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - M. S. Saharan
- Division of Plant Pathology, Fungal Molecular Biology Laboratory, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - M. S. Gurjar
- Division of Plant Pathology, Fungal Molecular Biology Laboratory, ICAR-Indian Agricultural Research Institute, New Delhi, 110012 India
| | - Amolkumar U. Solanke
- ICAR-National Institute for Plant Biotechnology, ICAR-IARI, New Delhi, 110012 India
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Dreiseitl A. Rare Virulences and Great Pathotype Diversity of a Central European Blumeria hordei Population. J Fungi (Basel) 2023; 9:1045. [PMID: 37998851 PMCID: PMC10672294 DOI: 10.3390/jof9111045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2023] [Revised: 10/20/2023] [Accepted: 10/23/2023] [Indexed: 11/25/2023] Open
Abstract
Barley is an important crop grown on almost 49 Mha worldwide in 2021 and is particularly significant in Europe where powdery mildew is the most frequent disease on susceptible varieties. The most suitable way to protect crops is by exploiting genetic resistance. However, the causal agent Blumeria hordei is an extremely adaptable pathogen. The aims of this research were to increase our knowledge of the rapidly changing pathogen population and detect rare virulences. Random samples of the pathogen were obtained from the air by means of a mobile spore sampler. Spores were collected by driving across the Czech Republic in 2019, 2021 and 2023, and 299 isolates were analyzed on 121 host varieties. No infection occurred on 35 differentials, rare virulence was recorded on 31 varieties and a higher virulence frequency was found on 55 differentials. A core set of differentials along with four additional varieties distinguishes 295 pathotypes (Simple Index = 0.987) and the virulence complexity of isolates varied from 4 to 19 with an average of 10.39. The detection of new virulences, the increasing frequency of previously rare virulences and high pathotype diversity as well as high virulence complexity confirm that using nonspecific durable resistance is crucial for successfully breeding commercial varieties.
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Affiliation(s)
- Antonín Dreiseitl
- Department of Integrated Plant Protection, Agrotest Fyto Ltd., 767 01 Kroměříž, Czech Republic
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Seethapathy P, Sankaralingam S, Pandita D, Pandita A, Loganathan K, Wani SH, El-Ansary DO, Sharma H, Casini R, Mahmoud EA, Elansary HO. Genetic Diversity Analysis based on the Virulence, Physiology and Regional Variability in Different Isolates of Powdery Mildew in Pea. J Fungi (Basel) 2022; 8:jof8080798. [PMID: 36012787 PMCID: PMC9409743 DOI: 10.3390/jof8080798] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 07/24/2022] [Accepted: 07/27/2022] [Indexed: 12/02/2022] Open
Abstract
Powdery mildew is an omnipresent disease that reduces the yield and quality of pea crops (Pisum sativum L.). To examine the powdery mildew pathogen’s morphological, molecular, and genetic diversity, we collected samples of powdery mildew-affected pea crops from ten distinct locations in the Nilgiris district of Tamil Nadu, India. The pathogen Erysiphe pisi was identified morphologically based on anamorphic characters. Molecular identification of E. pisi isolates was befitted by targeting the internal transcribed spacer (ITS) region of rDNA and specific primers of powdery mildew fungi. The genetic variation between ten different E. pisi isolates collected from topographically distinct mountainous areas was studied using random amplified polymorphic (RAPD). Based on its morphological characteristics, the powdery mildew fungus presented high similarities to E. pisi. Molecular characterization of the ITS rDNA of E. pisi produced 650 bp nucleotides, PMITS (powdery mildew-internal transcribed region) primers produced 700 bp nucleotides, and an Erysiphe specific ITS primer pair amplified and synthesized 560 bp nucleotides. According to the findings, the collected E. pisi strains exhibited a low level of genetic diversity and only a slight differential in virulence on the host. In the study, E. pisi isolates from Anumapuram, Emerald Valley, Indira Nagar, and Thuneri showed a greater disease incidence in the natural field conditions and shared the same genetic lineage with other isolates in UPGMA hierarchical cluster analysis based on RAPD markers. There was no evidence of a link between the occurrence of the disease and these grouped populations.
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Affiliation(s)
- Parthasarathy Seethapathy
- Department of Plant Pathology, Amrita School of Agricultural Sciences, Amrita Vishwa Vidyapeetham, Coimbatore 642109, India
- Correspondence: (P.S.); (D.P.)
| | - Subbiah Sankaralingam
- PG and Research Department of Botany, Saraswathi Narayanan College, Madurai 625022, India;
| | - Deepu Pandita
- Government Department of School Education, Jammu 180001, India
- Correspondence: (P.S.); (D.P.)
| | - Anu Pandita
- Vatsalya Clinic, Krishna Nagar, New Delhi 110051, India;
| | | | - Shabir Hussain Wani
- Mountain Research Centre for Field Crops, Sher-e-Kashmir University of Agricultural Sciences and Technology of Kashmir, Khudwani Anantnag 192101, Jammu and Kashmir, India;
| | - Diaa O. El-Ansary
- Precision Agriculture Laboratory, Department of Pomology, Faculty of Agriculture (El-Shatby), Alexandria University, Alexandria 21545, Egypt;
| | - Hanoor Sharma
- Microbiology and Immunology Department, Wright State University, Dayton, OH 45435, USA;
| | - Ryan Casini
- College of Public Health, University of California, Berkeley, 2121 Berkeley Way, Berkeley, CA 94704, USA;
| | - Eman A. Mahmoud
- Department of Food Industries, Faculty of Agriculture, Damietta University, Damietta 34511, Egypt;
| | - Hosam O. Elansary
- Plant Production Department, College of Food & Agriculture Sciences, King Saud University, Riyadh 11451, Saudi Arabia;
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Sotiropoulos AG, Arango-Isaza E, Ban T, Barbieri C, Bourras S, Cowger C, Czembor PC, Ben-David R, Dinoor A, Ellwood SR, Graf J, Hatta K, Helguera M, Sánchez-Martín J, McDonald BA, Morgounov AI, Müller MC, Shamanin V, Shimizu KK, Yoshihira T, Zbinden H, Keller B, Wicker T. Global genomic analyses of wheat powdery mildew reveal association of pathogen spread with historical human migration and trade. Nat Commun 2022; 13:4315. [PMID: 35882860 PMCID: PMC9315327 DOI: 10.1038/s41467-022-31975-0] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2021] [Accepted: 07/13/2022] [Indexed: 12/25/2022] Open
Abstract
The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, we study its spread and evolution by analyzing a global sample of 172 mildew genomes. Our analyses show that B.g. tritici emerged in the Fertile Crescent during wheat domestication. After it spread throughout Eurasia, colonization brought it to America, where it hybridized with unknown grass mildew species. Recent trade brought USA strains to Japan, and European strains to China. In both places, they hybridized with local ancestral strains. Thus, although mildew spreads by wind regionally, our results indicate that humans drove its global spread throughout history and that mildew rapidly evolved through hybridization. The fungus Blumeria graminis f. sp. tritici causes wheat powdery mildew disease. Here, Sotiropoulos et al. analyze a global sample of 172 mildew genomes, providing evidence that humans drove global spread of the pathogen throughout history and that mildew rapidly evolved through hybridization with local fungal strains.
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Affiliation(s)
| | - Epifanía Arango-Isaza
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland
| | - Tomohiro Ban
- Kihara Institute for Biological Research, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Chiara Barbieri
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Department of Linguistic and Cultural Evolution, Max Planck Institute for Evolutionary Anthropology, Leipzig, 04103, Germany
| | - Salim Bourras
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.,Department of Forest Mycology and Plant Pathology, Swedish University of Agricultural Sciences, Uppsala, Sweden
| | - Christina Cowger
- USDA-ARS Department of Plant Pathology, North Carolina State University, Raleigh, NC, USA
| | - Paweł C Czembor
- Plant Breeding and Acclimatization Institute - National Research Institute, Radzików, 05-870 Błonie, Poland
| | - Roi Ben-David
- Department of Vegetables and Field crops, Institute of Plant Sciences, ARO-Volcani Center, Rishon LeZion, 7528809, Israel
| | - Amos Dinoor
- Department of Plant Pathology and Microbiology, The Robert H. Smith Faculty of Agriculture, Food & Environment, The Hebrew University of Jerusalem, Rehovot, Israel
| | - Simon R Ellwood
- Centre for Crop and Disease Management, School of Molecular and Life Sciences, Curtin University, Bentley, WA, 6102, Australia
| | - Johannes Graf
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Koichi Hatta
- Hokkaido Agricultural Research Center Field Crop Research and Development, National Agricultural Research Organization, Sapporo, Hokkaido, Japan
| | - Marcelo Helguera
- Centro de Investigaciones Agropecuarias (CIAP), INTA, Córdoba, Argentina
| | - Javier Sánchez-Martín
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Bruce A McDonald
- Plant Pathology, Institute of Integrative Biology, ETH Zurich, Zurich, Switzerland
| | - Alexey I Morgounov
- Food and Agriculture Organization of the United Nations, Riyadh, Saudi Arabia
| | - Marion C Müller
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | | | - Kentaro K Shimizu
- Department of Evolutionary Biology and Environmental Studies, University of Zurich, Zurich, Switzerland.,Kihara Institute for Biological Research, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Taiki Yoshihira
- Department of Sustainable Agriculture, Rakuno Gakuen University, Ebetsu, Hokkaido, Japan
| | - Helen Zbinden
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Beat Keller
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland
| | - Thomas Wicker
- Department of Plant and Microbial Biology, University of Zurich, Zurich, Switzerland.
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Virulence Structure and Genetic Diversity of Blumeria graminis f. sp. avenae from Different Regions of Europe. PLANTS 2022; 11:plants11101358. [PMID: 35631783 PMCID: PMC9145444 DOI: 10.3390/plants11101358] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/22/2022] [Revised: 05/14/2022] [Accepted: 05/18/2022] [Indexed: 11/17/2022]
Abstract
The structure and dynamics of changes in pathogen populations can be analysed by assessing the level of virulence and genetic diversity. The aim of the present study was to determine the diversity of Blumeria graminis f. sp. avenae populations. Diversity and virulence of B. graminis f. sp. avenae was assessed based on 80 single-spore isolates collected in different European countries such as Poland (40 isolates), Germany (10), Finland (10), Czech Republic (10) and Ireland (10) using ISSR (Inter-Simple Sequence Repeats) and SCoT (Start Codon Targeted) markers. This work demonstrated differences in virulence of B. graminis f. sp. avenae isolates sampled from different countries. Molecular analysis showed that both systems were useful for assessing genetic diversity, but ISSR markers were superior and generated more polymorphic products, as well as higher PIC and RP values. UPMGA and PCoA divided the isolates into groups corresponding with their geographical origin. In conclusion, the low level of genetic differentiation of the analysed isolates has suggested that the evolution of B. graminis f. sp. Avenae population is slow, and thus the evolutionary potential of the pathogen is low. This work paves the way for future studies on B. graminis f. sp. Avenae population structure and dynamics based on genetic variability.
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Zwyrtková J, Blavet N, Doležalová A, Cápal P, Said M, Molnár I, Vrána J, Doležel J, Hřibová E. Draft Sequencing Crested Wheatgrass Chromosomes Identified Evolutionary Structural Changes and Genes and Facilitated the Development of SSR Markers. Int J Mol Sci 2022; 23:ijms23063191. [PMID: 35328613 PMCID: PMC8948999 DOI: 10.3390/ijms23063191] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2022] [Revised: 03/13/2022] [Accepted: 03/14/2022] [Indexed: 02/01/2023] Open
Abstract
Crested wheatgrass (Agropyron cristatum), a wild relative of wheat, is an attractive source of genes and alleles for their improvement. Its wider use is hampered by limited knowledge of its complex genome. In this work, individual chromosomes were purified by flow sorting, and DNA shotgun sequencing was performed. The annotation of chromosome-specific sequences characterized the DNA-repeat content and led to the identification of genic sequences. Among them, genic sequences homologous to genes conferring plant disease resistance and involved in plant tolerance to biotic and abiotic stress were identified. Genes belonging to the important groups for breeders involved in different functional categories were found. The analysis of the DNA-repeat content identified a new LTR element, Agrocen, which is enriched in centromeric regions. The colocalization of the element with the centromeric histone H3 variant CENH3 suggested its functional role in the grass centromere. Finally, 159 polymorphic simple-sequence-repeat (SSR) markers were identified, with 72 of them being chromosome- or chromosome-arm-specific, 16 mapping to more than one chromosome, and 71 mapping to all the Agropyron chromosomes. The markers were used to characterize orthologous relationships between A. cristatum and common wheat that will facilitate the introgression breeding of wheat using A. cristatum.
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Cieplak M, Terlecka K, Ociepa T, Zimowska B, Okoń S. Virulence Structure of Blumeria graminis f. sp. avenae Populations in Poland across 2014-2015. THE PLANT PATHOLOGY JOURNAL 2021; 37:115-123. [PMID: 33866754 PMCID: PMC8053843 DOI: 10.5423/ppj.oa.10.2020.0193] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/15/2020] [Revised: 01/19/2021] [Accepted: 01/25/2021] [Indexed: 06/12/2023]
Abstract
The purpose of this study was to determine the virulence structure of oat powdery mildew (Blumeria graminis f. sp. avenae, Bga) populations in Poland collected in 2014 and 2015. Powdery mildew isolates were collected from 18 locations in Poland. In total, nine lines and cultivars of oat, with different mildew resistance genes, were used to assess virulence of 180 isolates. The results showed that a significant proportion of the Bga isolates found in Poland were virulent to differentials with Pm1, Pm3, Pm6, and Pm3 + Pm8 genes. In contrast Pm4, Pm5, Pm2, and Pm7 genes were classified as resistant to all pathogen isolates used in the experiment. Based on obtained results we can state that there are differences in virulence pattern and diversity parameters between sites and years, but clear trends are not deducible.
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Affiliation(s)
- Magdalena Cieplak
- Institiute of Plant Genetics, Breeding and Biotechnology, University of Life Science, Akademicka 15 Str, 20-950 Lublin,
Poland
| | - Katarzyna Terlecka
- Institiute of Plant Genetics, Breeding and Biotechnology, University of Life Science, Akademicka 15 Str, 20-950 Lublin,
Poland
| | - Tomasz Ociepa
- Institiute of Plant Genetics, Breeding and Biotechnology, University of Life Science, Akademicka 15 Str, 20-950 Lublin,
Poland
| | - Beata Zimowska
- Department of Plant Protection, University of Life Sciences, Leszczyńskiego 7 Str, 20-069 Lublin,
Poland
| | - Sylwia Okoń
- Institiute of Plant Genetics, Breeding and Biotechnology, University of Life Science, Akademicka 15 Str, 20-950 Lublin,
Poland
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Gent DH, Claassen BJ, Gadoury DM, Grünwald NJ, Knaus BJ, Radišek S, Weldon W, Wiseman MS, Wolfenbarger SN. Population Diversity and Structure of Podosphaera macularis in the Pacific Northwestern United States and Other Populations. PHYTOPATHOLOGY 2020; 110:1105-1116. [PMID: 32091314 DOI: 10.1094/phyto-12-19-0448-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/10/2023]
Abstract
Powdery mildew, caused by Podosphaera macularis, is one of the most important diseases of hop. The disease was first reported in the Pacific Northwestern United States, the primary hop-growing region in this country, in the mid-1990s. More recently, the disease has reemerged in newly planted hopyards of the eastern United States, as hop production has expanded to meet demands of local craft brewers. The spread of strains virulent on previously resistant cultivars, the paucity of available fungicides, and the potential introduction of the MAT1-2 mating type to the western United States, all threaten sustainability of hop production. We sequenced the transcriptome of 104 isolates of P. macularis collected throughout the western United States, eastern United States, and Europe to quantify genetic diversity of pathogen populations and elucidate the possible origins of pathogen populations in the western United States. Discriminant analysis of principal components grouped isolates within three to five geographic populations, dependent on stringency of grouping criteria. Isolates from the western United States were phenotyped and categorized into one of three pathogenic races based on disease symptoms generated on differential cultivars. Western U.S. populations were clonal, irrespective of pathogenic race, and grouped with isolates originating from Europe. Isolates originating from wild hop plants in the eastern United States were genetically differentiated from all other populations, whereas isolates from cultivated hop plants in the eastern United States mostly grouped with isolates originating from the west, consistent with origins from nursery sources. Mating types of isolates originating from cultivated western and eastern U.S. hop plants were entirely MAT1-1. In contrast, a 1:1 ratio of MAT1-1 and MAT1-2 was observed with isolates sampled from wild plants or Europe. Within the western United States a set of highly differentiated loci were identified in P. macularis isolates associated with virulence to the powdery mildew R-gene R6. The weight of genetic and phenotypic evidence suggests a European origin of the P. macularis populations in the western United States, followed by spread of the pathogen from the western United States to re-emergent production regions in the eastern United States. Furthermore, R6 compatibility appears to have been selected from an extant isolate within the western United States. Greater emphasis on sanitation measures during propagation and quarantine policies should be considered to limit further spread of novel genotypes of the pathogen, both between and within production areas.
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Affiliation(s)
- David H Gent
- U.S. Department of Agriculture-Agricultural Research Service, Forage Seed and Cereal Research Unit, Corvallis, OR 97331, U.S.A
| | - Briana J Claassen
- Oregon State University, Department of Botany and Plant Pathology, Corvallis, OR 97331, U.S.A
| | - David M Gadoury
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, U.S.A
| | - Niklaus J Grünwald
- U.S. Department of Agriculture-Agricultural Research Service, Horticultural Crops Research Unit, Corvallis, OR 97330, U.S.A
| | - Brian J Knaus
- Oregon State University, Department of Botany and Plant Pathology, Corvallis, OR 97331, U.S.A
| | | | - William Weldon
- Plant Pathology and Plant-Microbe Biology Section, Cornell University, New York State Agricultural Experiment Station, Geneva, NY 14456, U.S.A
| | - Michele S Wiseman
- Oregon State University, Department of Botany and Plant Pathology, Corvallis, OR 97331, U.S.A
| | - Sierra N Wolfenbarger
- Oregon State University, Department of Botany and Plant Pathology, Corvallis, OR 97331, U.S.A
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Dreiseitl A, Zavřelová M. Identification of barley powdery mildew resistances in gene bank accessions and the use of gene diversity for verifying seed purity and authenticity. PLoS One 2018; 13:e0208719. [PMID: 30532221 PMCID: PMC6285996 DOI: 10.1371/journal.pone.0208719] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2018] [Accepted: 11/22/2018] [Indexed: 11/18/2022] Open
Abstract
Human activities including those in crop gene banks are subject to errors, especially during seed multiplication and maintenance of seed germination. Therefore, the most serious problem of gene banks is authenticity of the accessions and their genotypic purity. There are many methods for determining the identity of varieties, but comparisons between current data and past records are not easy since the latter are often missing. Breeding barley resistant to powdery mildew caused by Blumeria graminis f. sp. hordei (Bgh) was traditionally based on incorporating major genes into new varieties and the results have been published. Our goal was to identify resistance genes to powdery mildew in accessions of the Czech spring barley core collection and compare these data with earlier information to establish the authenticity of the accessions. Two hundred and twenty-three accessions of the collection including 665 single plant progenies were tested. Sixty-four selected reference isolates of Bgh representing the world diversity of the pathogen were used for resistance tests. Twenty-two known resistance genes were postulated either separately or in combinations. In the collection, 151 homogeneous accessions were found, but the resistances of nine of them were inconsistent with published data and in 12 accessions their authenticity is doubtful. The remaining 72 accessions were heterogeneous and comprised 176 resistance genotypes, 54 of which were probably mechanical admixtures of other varieties. There are several pathogens of cereals, e.g. rusts and mildews, against which many resistance genes in host crops have also been exploited. Knowledge of these resistances can assist in maintaining pure and genuine stocks in gene banks. Seed purity and the authenticity of accessions can subsequently be checked with more advanced methods.
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Affiliation(s)
- Antonín Dreiseitl
- Department of Integrated Plant Protection, Agrotest Fyto Ltd., Kroměříž, Czech Republic
| | - Marta Zavřelová
- Department of Plant Genetics and Breeding, Agrotest Fyto Ltd., Kroměříž, Czech Republic
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