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Fan K, Qi YK, Fu L, Li L, Liu XH, Qu JL, Li DW, Dong AX, Peng YJ, Wang QH. Identification and Fungicide Screening of Fungal Species Associated with Walnut Anthracnose in Shaanxi and Liaoning Provinces, China. Plant Dis 2024; 108:599-607. [PMID: 37682223 DOI: 10.1094/pdis-05-23-0967-re] [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: 09/09/2023]
Abstract
Walnut is cultivated around the world for its precious woody nut and edible oil. Recently, walnut infected by Colletotrichum spp. resulted in a great yield and quality loss. In August and September 2014, walnut fruits with anthracnose were sampled from two commercial orchards in Shaanxi and Liaoning provinces, and five representative isolates were used in this study. To identify the pathogen properly, four genes per region (internal transcribed spacer, glyceraldehyde-3-phosphate dehydrogenase, actin, and chitin synthase) were sequenced and used in phylogenetic studies. Based on multilocus phylogenetic analysis, five isolates clustered with Colletotrichum fioriniae, including its ex-type, with 100% bootstrap support. The results of multilocus phylogenetic analyses, morphology, and pathogenicity confirmed that C. fioriniae was one of the walnut anthracnose pathogens in China. All 13 fungicides tested inhibited mycelial growth and spore germination. Flusilazole, fluazinam, prochloraz, and pyraclostrobin showed the strongest suppressive effects on the mycelial growth than the others, the average EC50 values ranged from 0.09 to 0.40 μg/ml, and there was not any significant difference (P < 0.05). Pyraclostrobin, thiram, and azoxystrobin were the most effective fungicides on spore germination (P < 0.05), and the EC50 values ranged from 0.01 to 0.44 μg/ml. Pyraclostrobin, azoxystrobin, fluazinam, flusilazole, mancozeb, thiram, and prochloraz exhibited a good control effect on walnut anthracnose caused by C. fioriniae, and preventive activities were greater than curative activities. Pyraclostrobin at 250 a.i. μg/ml and fluazinam at 500 a.i. μg/ml provided the highest preventive and curative efficacy, and the values ranged from 81.3 to 82.2% and from 72.9 to 73.6%, respectively. As a consequence, mancozeb and thiram could be used at the preinfection stage, and pyraclostrobin, azoxystrobin, flusilazole, fluazinam, and prochloraz could be used at the early stage for effective prevention and control of walnut anthracnose caused by C. fioriniae. The results will provide more significant instructions for controlling the disease effectively in northern China.
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Affiliation(s)
- Kun Fan
- Shandong Institute of Pomology, Taian, Shandong 271000, China
| | - Yu-Kun Qi
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Li Fu
- Shandong Institute of Pomology, Taian, Shandong 271000, China
| | - Li Li
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Xing-Hong Liu
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Jian-Lu Qu
- Shandong Institute of Pomology, Taian, Shandong 271000, China
| | - De-Wei Li
- The Connecticut Agricultural Experiment Station Valley Laboratory, Windsor, CT 06095, U.S.A
| | - Ai-Xin Dong
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Yi-Ji Peng
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Qing-Hai Wang
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
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Theologidis I, Karamitros T, Vichou AE, Kizis D. Nanopore-Sequencing Metabarcoding for Identification of Phytopathogenic and Endophytic Fungi in Olive ( Olea europaea) Twigs. J Fungi (Basel) 2023; 9:1119. [PMID: 37998924 PMCID: PMC10672464 DOI: 10.3390/jof9111119] [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] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Revised: 11/13/2023] [Accepted: 11/16/2023] [Indexed: 11/25/2023] Open
Abstract
Metabarcoding approaches for the identification of plant disease pathogens and characterization of plant microbial populations constitute a rapidly evolving research field. Fungal plant diseases are of major phytopathological concern; thus, the development of metabarcoding approaches for the detection of phytopathogenic fungi is becoming increasingly imperative in the context of plant disease prognosis. We developed a multiplex metabarcoding method for the identification of fungal phytopathogens and endophytes in olive young shoots, using the MinION sequencing platform (Oxford Nanopore Technologies). Selected fungal-specific primers were used to amplify three different genomic DNA loci (ITS, beta-tubulin, and 28S LSU) originating from olive twigs. A multiplex metabarcoding approach was initially evaluated using healthy olive twigs, and further assessed with naturally infected olive twig samples. Bioinformatic analysis of basecalled reads was carried out using MinKNOW, BLAST+ and R programming, and results were also evaluated using the BugSeq cloud platform. Data analysis highlighted the approaches based on ITS and their combination with beta-tubulin as the most informative ones according to diversity estimations. Subsequent implementation of the method on symptomatic samples identified major olive pathogens and endophytes including genera such as Cladosporium, Didymosphaeria, Paraconiothyrium, Penicillium, Phoma, Verticillium, and others.
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Affiliation(s)
- Ioannis Theologidis
- Laboratory of Toxicological Control of Pesticides, Scientific Directorate of Pesticides' Control & Phytopharmacy, Benaki Phytopathological Institute, 8 St. Delta Street, 14561 Athens, Attica, Greece
| | - Timokratis Karamitros
- Bioinformatics and Applied Genomics Unit, Department of Microbiology, Hellenic Pasteur Institute, 127 Vasilissis Sofias Avenue, 11521 Athens, Attica, Greece
| | - Aikaterini-Eleni Vichou
- Laboratory of Mycology, Scientific Directorate of Phytopathology, Benaki Phytopathological Institute, 8 St. Delta Street, 14561 Athens, Attica, Greece
| | - Dimosthenis Kizis
- Laboratory of Mycology, Scientific Directorate of Phytopathology, Benaki Phytopathological Institute, 8 St. Delta Street, 14561 Athens, Attica, Greece
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Zhang L, Yin YQ, Zhao LL, Xie YQ, Han J, Zhang Y. Two new species of Colletotrichum (Glomerellaceae, Glomerellales) causing walnut anthracnose in Beijing. MycoKeys 2023; 99:131-152. [PMID: 37719302 PMCID: PMC10502704 DOI: 10.3897/mycokeys.99.106812] [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] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2023] [Accepted: 08/05/2023] [Indexed: 09/19/2023] Open
Abstract
Colletotrichum species are plant pathogens, saprobes and endophytes on various plant hosts. It is regarded as one of the 10 most important genera of plant pathogens in the world. Walnut anthracnose is one of the most severe diseases affecting walnut productivity and quality in China. In this study, 162 isolates were obtained from 30 fruits and 65 leaf samples of walnut collected in Beijing, China. Based on morphological characteristics and DNA sequence analyses of the concatenated loci, namely internal transcribed spacer (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), chitin synthase 1 (CHS-1) and beta-tubulin (TUB2), these isolates were identified as two novel species of Colletotrichum, i.e. C.juglandicola and C.peakense. Koch's postulates indicated that both C.juglandicola and C.peakense could cause anthracnose in walnut.
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Affiliation(s)
- Lin Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaBeijing Forestry UniversityBeijingChina
| | - Yue-Qi Yin
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaBeijing Forestry UniversityBeijingChina
| | - Li-Li Zhao
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaBeijing Forestry UniversityBeijingChina
| | - Yu-Qing Xie
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaBeijing Forestry UniversityBeijingChina
| | - Jing Han
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaBeijing Forestry UniversityBeijingChina
| | - Ying Zhang
- School of Ecology and Nature Conservation, Beijing Forestry University, Beijing 100083, ChinaBeijing Forestry UniversityBeijingChina
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Wang L, Zhu T. Strong Opponent of Walnut Anthracnose- Bacillus velezensis and Its Transcriptome Analysis. Microorganisms 2023; 11:1885. [PMID: 37630445 PMCID: PMC10456653 DOI: 10.3390/microorganisms11081885] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2023] [Revised: 07/23/2023] [Accepted: 07/24/2023] [Indexed: 08/27/2023] Open
Abstract
Walnut is a significant economic tree species worldwide. Walnut anthracnose, caused by the pathogen Colletotrichum gloeosporioides, greatly reduces walnut production and economic benefits. Our study showed that Bacillus velezensis effectively halted the growth of C. gloeosporioides, inducing noticeable abnormalities such as hyphal breakage and distortion, thereby curtailing the pathogen's virulence. A 50-100 times dilution of B. velezensis fermentation broth, applied every two to three days, served as an efficient protective layer for walnut leaves and fruits against C. gloeosporioides infection. Transcriptomic analysis of B. velezensis unveiled its dynamic response against C. gloeosporioides. On the second day, B. velezensis upregulated a significant number of differentially expressed genes related to the synthesis of metabolic products, amino acid biosynthesis, and motility. On the fourth day, continuous synthesis of metabolic products and amino acids, along with differential expression of spore-related genes, was observed. By the sixth day, the focus shifted towards environmental adaptation and carbon source utilization. Throughout the process, B. velezensis likely employed strategies such as the release of metabolic products, increased chemotaxis, and nutrient competition to exert its antagonistic effect on C. gloeosporioides. Fluorescence quantitative results showed that 15 primer pairs were up-regulated and 15 were down-regulated, with a 100% similarity rate to transcriptome sequencing results, confirming their authenticity. These findings provided a foundation for the widespread application of B. velezensis as a biocontrol agent in agriculture and forestry.
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Affiliation(s)
| | - Tianhui Zhu
- College of Forestry, Sichuan Agricultural University, Yaan 625000, China
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Belair M, Pensec F, Jany JL, Le Floch G, Picot A. Profiling Walnut Fungal Pathobiome Associated with Walnut Dieback Using Community-Targeted DNA Metabarcoding. Plants (Basel) 2023; 12:2383. [PMID: 37376008 DOI: 10.3390/plants12122383] [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] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/03/2023] [Revised: 06/06/2023] [Accepted: 06/12/2023] [Indexed: 06/29/2023]
Abstract
Walnut dieback can be caused by several fungal pathogenic species, which are associated with symptoms ranging from branch dieback to fruit necrosis and blight, challenging the one pathogen-one disease concept. Therefore, an accurate and extensive description of the walnut fungal pathobiome is crucial. To this end, DNA metabarcoding represents a powerful approach provided that bioinformatic pipelines are evaluated to avoid misinterpretation. In this context, this study aimed to determine (i) the performance of five primer pairs targeting the ITS region in amplifying genera of interest and estimating their relative abundance based on mock communities and (ii) the degree of taxonomic resolution using phylogenetic trees. Furthermore, our pipelines were also applied to DNA sequences from symptomatic walnut husks and twigs. Overall, our results showed that the ITS2 region was a better barcode than ITS1 and ITS, resulting in significantly higher sensitivity and/or similarity of composition values. The ITS3/ITS4_KYO1 primer set allowed to cover a wider range of fungal diversity, compared to the other primer sets also targeting the ITS2 region, namely, GTAA and GTAAm. Adding an extraction step to the ITS2 sequence influenced both positively and negatively the taxonomic resolution at the genus and species level, depending on the primer pair considered. Taken together, these results suggested that Kyo set without ITS2 extraction was the best pipeline to assess the broadest fungal diversity, with a more accurate taxonomic assignment, in walnut organs with dieback symptoms.
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Affiliation(s)
- Marie Belair
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, University Brest, F-29280 Plouzané, France
| | - Flora Pensec
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, University Brest, F-29280 Plouzané, France
| | - Jean-Luc Jany
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, University Brest, F-29280 Plouzané, France
| | - Gaétan Le Floch
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, University Brest, F-29280 Plouzané, France
| | - Adeline Picot
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, INRAE, University Brest, F-29280 Plouzané, France
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Peng K, Pan Y, Tan T, Zeng X, Lin M, Jiang S, Zhao Z, Tian F, Zhao X. Characterization and fungicide sensitivity of Colletotrichum godetiae causing sweet cherry fruit anthracnose in Guizhou, China. Front Microbiol 2022; 13:923181. [PMID: 36312935 PMCID: PMC9611538 DOI: 10.3389/fmicb.2022.923181] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2022] [Accepted: 08/12/2022] [Indexed: 11/17/2022] Open
Abstract
Sweet cherry is an important fruit crop with high economic and ornamental value in China. However, cherry fruit anthracnose, caused by Colletotrichum species, greatly impacts cherry yield and quality. Here, we surveyed cherry anthracnose in Guizhou, China from 2019–2020. Necrotic sweet cherry fruits were collected from different areas in Guizhou and examined. A total of 116 Colletotrichum strains were isolated from these symptomatic fruits. Based on the morphological characteristics of the isolates and phylogenetic analyses of concatenate internal transcribed spacer (ITS) region and ACT, CHS-1, GAPDH, TUB2, and HIS3 genes, the pathogen responsible for causing sweet cherry anthracnose was identified as Colletotrichum godetiae. Pathogenicity tests were conducted by inoculating healthy sweet cherry fruits with spore suspensions of the fungal pathogen, and Koch’s postulates were confirmed by pathogen re-isolation and identification. The Q-1 isolate showed different sensitivities to 13 fungicides, exhibiting seven different modes of action, and its EC50 values ranged from 0.04 to 91.26 μg ml−1. According to that, the sensitivity of 20 isolates from different samples to ten fungicides with better performance, were measured. The results showed that 6 of the 10 fungicides (difenoconazole, propiconazole, prochloraz-manganese, pyraclostrobin, trifloxystrobin-tebuconazole, and difenoconazole-azoxystrobin) all showed higher sensitive to the 20\u00B0C. godetiae isolates, and no resistance groups appeared. Its EC50 values ranged from 0.013 to 1.563 μg ml−1. In summary, this is the first report demonstrating that C. godetiae causes sweet cherry anthracnose and the results of this study provide insights into how sweet cherry anthracnose could be effectively controlled in China.
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Wang S, Tan Y, Li S, Zhu T. Structural and Dynamic Analysis of Leaf-Associated Fungal Community of Walnut Leaves Infected by Leaf Spot Disease Based Illumina High-Throughput Sequencing Technology. Pol J Microbiol 2022; 71:429-441. [PMID: 36185023 PMCID: PMC9608163 DOI: 10.33073/pjm-2022-038] [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] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2022] [Accepted: 07/25/2022] [Indexed: 11/24/2022] Open
Abstract
Leaf-associated microbiota is vital in plant-environment interactions and is the basis for micro-ecological regulation. However, there are no studies on the direct differences in microbial community composition between disease-susceptible and healthy walnut leaves. This study collected five samples of healthy and infected leaves (all leaves with abnormal spots were considered diseased leaves) from May to October 2018. Differences in fungal diversity (Chao1 index, Shannon index, and Simpson index) and community structure were observed by sequencing and analyzing diseased and healthy leaf microbial communities by Illumina HiSeq sequencing technology. The main fungal phyla of walnut leaf-associated were Ascomycota, Basidiomycota, and Glomeromycota. Diversity indices (Shannon and Chao1 index values) of healthy leaves differed significantly in the late stages of disease onset. The results showed that the fungal species that differed considerably between the healthy and infected groups differed, and the fungal species that differed significantly between the healthy and infected groups changed with the development of the leaf disease. Critical control time points were determined by analyzing the population dynamics of pathogenic fungi. Leaf-associated microorganisms are abundant and diverse, and fungal identification and diversity studies are helpful for developing more appropriate walnut management strategies.
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Affiliation(s)
- Shiwei Wang
- College of Forestry, Sichuan Agricultural University, Chengdu, China
| | - Yu Tan
- College of Forestry, Sichuan Agricultural University, Chengdu, China,Chengdu Botanical Garden, Chengdu, China
| | - Shujiang Li
- College of Forestry, Sichuan Agricultural University, Chengdu, China,National Forestry and Grassland Administration Key Laboratory of Forest Resources Conservation and Ecological Safety on the Upper Reaches of the Yangtze River, Chengdu, China
| | - Tianhui Zhu
- College of Forestry, Sichuan Agricultural University, Chengdu, China, T. Zhu, College of Forestry, Sichuan Agricultural University , Chengdu, China # Shiwei Wang and Yu Tan contribute equally to this work and are co-first authors.
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Aragona M, Haegi A, Valente MT, Riccioni L, Orzali L, Vitale S, Luongo L, Infantino A. New-Generation Sequencing Technology in Diagnosis of Fungal Plant Pathogens: A Dream Comes True? J Fungi (Basel) 2022; 8:737. [PMID: 35887492 DOI: 10.3390/jof8070737] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2022] [Revised: 07/01/2022] [Accepted: 07/11/2022] [Indexed: 02/01/2023] Open
Abstract
The fast and continued progress of high-throughput sequencing (HTS) and the drastic reduction of its costs have boosted new and unpredictable developments in the field of plant pathology. The cost of whole-genome sequencing, which, until few years ago, was prohibitive for many projects, is now so affordable that a new branch, phylogenomics, is being developed. Fungal taxonomy is being deeply influenced by genome comparison, too. It is now easier to discover new genes as potential targets for an accurate diagnosis of new or emerging pathogens, notably those of quarantine concern. Similarly, with the development of metabarcoding and metagenomics techniques, it is now possible to unravel complex diseases or answer crucial questions, such as "What's in my soil?", to a good approximation, including fungi, bacteria, nematodes, etc. The new technologies allow to redraw the approach for disease control strategies considering the pathogens within their environment and deciphering the complex interactions between microorganisms and the cultivated crops. This kind of analysis usually generates big data that need sophisticated bioinformatic tools (machine learning, artificial intelligence) for their management. Herein, examples of the use of new technologies for research in fungal diversity and diagnosis of some fungal pathogens are reported.
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Yang X, Wu L, Fu L, Fu P, Zhu J, Zhao Y, Liu J, Li P. Metabolomics Study on the Resistance of Walnut Peel to Colletotrichum gloeosporioides under Prochloraz Treatment. J CHEM-NY 2022; 2022:1-7. [DOI: 10.1155/2022/7613285] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Anthracnose, caused by Colletotrichum gloeosporioides, is highly harmful for walnut production in the world. To better control this disease, the inhibitory effects of 3 fungicides against Colletotrichum gloeosporioides were determined, and the results showed that prochloraz had better inhibitory activity. Through comparative metabolomics analysis, 311 metabolites might be associated with the walnut peel response to Colletotrichum gloeosporioides under prochloraz treatment. Furthermore, we supposed that the phenylpropanoid pathway might be induced by prochloraz to resist Colletotrichum gloeosporioides infection. In conclusion, the upregulated metabolites in the phenylpropanoid pathway might be related to synthesize lignin to further form a cell wall against Colletotrichum gloeosporioides infection.
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Wang Y, Xu X, Cai F, Huang F, Chen W, Wang Q. First Report of Colletotrichum nymphaeae Causing Walnut Anthracnose in China. Plant Dis 2022; 106:2991. [PMID: 35357180 DOI: 10.1094/pdis-02-22-0297-pdn] [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] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
Walnut (Juglans regia L.) is a high quality woody nut and edible oil tree with a planting area of about 5,000,000 hectare in China. Walnut anthracnose is a serious disease, infecting approximately 50% of the fruits and causing a great yield losses (Wang et al. 2016). In 2019 to 2020, walnut fruits with anthracnose symptoms were collected from walnut orchards in province of Hubei, Sichuan procinve and Chongqing municipality, China. Symptoms on fruits were circular or subcircular or irregular shaped, with brown to black water soaked and sunken lesions. The black lesions enlarged and amalgamated into large necrotic areas. The older spots in the center became blackish with acervuli causing the complete mummification of the fruit, and orange conidial masses appeared under wet conditions. Necrotic tissues of the fruits were sterilized in 75% ethanol solution for 30 s, then sterilized in 4% sodium hypochlorite for 1min, and washed 3 times with sterile distilled water. The tissues were put on potato dextrose agar (PDA) and incubated at 25℃. Pure cultures were obtained by single-spore culturing method and the isolate HBBK4-4 was deposited into the China's Forestry Culture Collection Center (CFCC 57388). On PDA, the colonies were cottony, white to pale gray with aerial mycelium on the upper side and pink with black spots on the reverse. The mycelial growth rate was 9.6 mm/day at 25°C. Conidia were 1-celled, colorless, smooth-walled, straight, cylindrical to cylindrical-clavate with acute ends, 12.5 to 18.2 × 3.9 to 5.4 μm (mean 15.3 ± 3.7 × 4.9 ± 0.6 μm, n = 40). Most conidia germinated and developed one pleurogenous, 1-celled appressorium. Appressoria were single, medium brown, smooth-walled, ovate to ellipsoid, 5.4 to 7.8 × 5.4 to 7.8 μm (mean 6.7 ± 0.6 × 6.3 ± 0.5 μm, n = 30). These morphological characteristics were in concordance with published descriptions of Collectotrichum acutatum species complex. To further confirm the identity, internal transcribed spacer (ITS), beta-tubulin (TUB2), chitin synthase 1 (CHS-I) and glyceraldehyde-3-phosphate dehydrogenase (GAPDH) genes were amplified and sequenced (Damm et al. 2012). The ITS (OM189549) and TUB2 (OM273642) sequences of isolate HBBK4-4 showed 100% similarity, and GAPDH (OM249791) and CHS-1 (OM273641) sequences showed 98.7% and 99.6% similarity with C. nymphaeae CBS100064 respectively. A maximum likelihood phylogenetic tree was generated based on combining all sequenced loci in MEGA5. 18 isolates including HBBK4-4 fell in the C. nymphaeae clade with 96% bootstrap support. To verify Koch's postulates, six isolates were used for pathogenicity test, and 20 healthy fruits and 15 fully expanded leaves for each isolate were inoculated with 5-mm-diameter mycelial plugs. Controls consisted of detached premature fruits inoculated with a PDA plug without the fungus. Six days after inoculation, all fruits and leaves developed anthracnose symptoms similar to those observed in the field, while the controls remained healthy. The pathogenicity tests were repeated twice with the same results. The morphology of the reisolated fungi was consistent with the inoculated one, fulfilling Koch's postulates. The isolate HBBK4-4 was identified as C. nymphaeae, based on the description by Damm et al. (2012). The species C. nymphaeae has been previously reported to cause severe anthracnose on walnut in France (Da Lio et al., 2018), Brazil (Savian et al., 2019) and Italy (Luongo et al., 2022). To our knowledge, this is the first report of C. nymphaeae as a pathogen of walnut anthracnose in China. The result provided crucial information for epidemiologic studies and management of this disease.
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Affiliation(s)
- Yixun Wang
- Hubei Academy of Forestry, forest protection, wuhan, hubei, China;
| | - Xiaowen Xu
- Hubei Academy of Forestry, forest protection, wuhan, China;
| | - Fang Cai
- Hubei Academy of Forestry, wuhan, China;
| | | | - Wansheng Chen
- Forestry Bureau of Baokang County, xiangyang, China;
| | - Qizhu Wang
- Forestry Bureau of Baokang County, xiangyang, China;
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Carneiro GA, Baric S. Colletotrichum fioriniae and Colletotrichum godetiae Causing Postharvest Bitter Rot of Apple in South Tyrol (Northern Italy). Plant Dis 2021; 105:3118-3126. [PMID: 33656363 DOI: 10.1094/pdis-11-20-2482-re] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [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: 06/12/2023]
Abstract
South Tyrol (northern Italy) harbors one of the largest interconnected apple farming areas in Europe, contributing approximately 10% to the apple production of the European Union. Despite the availability of sophisticated storage facilities, postharvest diseases occur, one of which is bitter rot of apple. In Europe, this postharvest disease is mainly caused by the Colletotrichum acutatum species complex. This study aimed to characterize the Colletotrichum spp. isolated from decayed apple fruit collected in 2018 and 2019 in South Tyrol. The characterization of Colletotrichum spp. was accomplished based on multilocus DNA sequences of four different genomic regions-actin (ACT), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), histone H3 (HIS3), and the internal transcribed spacer (ITS) region-as well as morphological and pathogenicity assessment. A phylogenetic analysis based on multilocus DNA sequences showed that the isolates obtained from apples with symptoms of bitter rot belonged to the species Colletotrichum godetiae and Colletotrichum fioriniae, which are part of the Colletotrichum acutatum species complex. A third species isolated from apples belonging to the same species complex, Colletotrichum salicis, was described in this area. Moreover, the Colletotrichum isolates found in this study proved to be virulent on Cripps Pink, Golden Delicious, and Roho 3615/Evelina. To the best of our knowledge, C. godetiae and C. fioriniae have so far never been mentioned as postharvest pathogens of apple in Italy, although the reanalysis of samples collected in the past indicates that these pathogens have been occurring in Italy for at least a decade. So far, bitter rot seems to play a minor role as a postharvest disease in South Tyrol, but it was disproportionately represented on a few scab-resistant apple cultivars, which are increasingly planted in organically managed orchards. Considering that the expansion of organic apple production and the conversion to new potentially Colletotrichum-susceptible cultivars will continue, the present study represents an important contribution toward a better understanding of bitter rot in this geographic area.[Formula: see text] Copyright © 2021 The Author(s). This is an open access article distributed under the CC BY 4.0 International license.
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Affiliation(s)
- Greice Amaral Carneiro
- Faculty of Science and Technology, Free University of Bozen-Bolzano, 39100 Bozen-Bolzano, Italy
| | - Sanja Baric
- Faculty of Science and Technology, Free University of Bozen-Bolzano, 39100 Bozen-Bolzano, Italy
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Choub V, Ajuna HB, Won SJ, Moon JH, Choi SI, Maung CEH, Kim CW, Ahn YS. Antifungal Activity of Bacillus velezensis CE 100 against Anthracnose Disease ( Colletotrichum gloeosporioides) and Growth Promotion of Walnut ( Juglans regia L.) Trees. Int J Mol Sci 2021; 22:ijms221910438. [PMID: 34638782 PMCID: PMC8508943 DOI: 10.3390/ijms221910438] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [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: 08/22/2021] [Revised: 09/24/2021] [Accepted: 09/24/2021] [Indexed: 11/16/2022] Open
Abstract
Walnut anthracnose caused by Colletotrichum gloeosporioides is a deleterious disease that severely affects the production of walnut (Juglans regia L.). The aim of this study was to assess the antifungal and growth promotion activities of Bacillus velezensis CE 100 as an alternative to chemical use in walnut production. The crude enzyme from B. velezensis CE 100 exhibited chitinase, protease, and β-l,3-glucanase activity and degraded the cell wall of C. gloeosporioides, causing the inhibition of spore germination and mycelial growth by 99.3% and 33.6% at 100 µL/mL, respectively. The field application of B. velezensis CE 100 culture broth resulted in a 1.3-fold and 6.9-fold decrease in anthracnose disease severity compared to the conventional and control groups, respectively. Moreover, B. velezensis CE 100 produced indole-3-acetic acid (up to 1.4 µg/mL) and exhibited the potential for ammonium production and phosphate solubilization to enhance the availability of essential nutrients. Thus, field inoculation of B. velezensis CE 100 improved walnut root development, increased nutrient uptake, enhanced chlorophyll content, and consequently improved total biomass by 1.5-fold and 2.0-fold compared to the conventional and control groups, respectively. These results demonstrate that B. velezensis CE 100 is an effective biocontrol agent against anthracnose disease and a potential plant growth-promoting bacteria in walnut tree production.
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Affiliation(s)
- Vantha Choub
- Department of Forest Resources, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.C.); (H.B.A.); (S.-J.W.); (J.-H.M.); (S.-I.C.)
| | - Henry B. Ajuna
- Department of Forest Resources, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.C.); (H.B.A.); (S.-J.W.); (J.-H.M.); (S.-I.C.)
| | - Sang-Jae Won
- Department of Forest Resources, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.C.); (H.B.A.); (S.-J.W.); (J.-H.M.); (S.-I.C.)
| | - Jae-Hyun Moon
- Department of Forest Resources, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.C.); (H.B.A.); (S.-J.W.); (J.-H.M.); (S.-I.C.)
| | - Su-In Choi
- Department of Forest Resources, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.C.); (H.B.A.); (S.-J.W.); (J.-H.M.); (S.-I.C.)
| | - Chaw Ei Htwe Maung
- Division of Agricultural and Biological Chemistry, Institute of Environmentally Friendly Agriculture, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea;
| | - Chul-Woo Kim
- Division of Special-purpose Trees, National Institute of Forest Science, Suwon 16631, Korea;
| | - Young Sang Ahn
- Department of Forest Resources, College of Agriculture and Life Sciences, Chonnam National University, Gwangju 61186, Korea; (V.C.); (H.B.A.); (S.-J.W.); (J.-H.M.); (S.-I.C.)
- Correspondence: ; Tel.: +82-62-530-2081; Fax: +82-62-530-2089
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Tso HH, Galindo-González L, Strelkov SE. Current and Future Pathotyping Platforms for Plasmodiophora brassicae in Canada. Plants (Basel) 2021; 10:1446. [PMID: 34371649 DOI: 10.3390/plants10071446] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/03/2021] [Revised: 07/06/2021] [Accepted: 07/12/2021] [Indexed: 11/17/2022]
Abstract
Clubroot, caused by Plasmodiophora brassicae, is one of the most detrimental threats to crucifers worldwide and has emerged as an important disease of canola (Brassica napus) in Canada. At present, pathotypes are distinguished phenotypically by their virulence patterns on host differential sets, including the systems of Williams, Somé et al., the European Clubroot Differential set, and most recently the Canadian Clubroot Differential set and the Sinitic Clubroot Differential set. Although these are frequently used because of their simplicity of application, they are time-consuming, labor-intensive, and can lack sensitivity. Early, preventative pathotype detection is imperative to maximize productivity and promote sustainable crop production. The decreased turnaround time and increased sensitivity and specificity of genotypic pathotyping will be valuable for the development of integrated clubroot management plans, and interest in molecular techniques to complement phenotypic methods is increasing. This review provides a synopsis of current and future molecular pathotyping platforms for P. brassicae and aims to provide information on techniques that may be most suitable for the development of rapid, reliable, and cost-effective pathotyping assays.
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Laura L, Galli M, Garaguso I, Petrucci M, Vitale S. First report of Colletotrichum fioriniae and C. nymphaeae as Causal Agents of anthracnose on walnut in Italy. Plant Dis 2021; 106:327. [PMID: 34261354 DOI: 10.1094/pdis-05-21-1062-pdn] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/13/2023]
Abstract
English walnut (Juglans regia L.) is species grown either for high quality wood or fruit production. In Italy walnut cultivation occupies an area of about 4600 ha (FAOSTAT, http://www.fao.org/faostat, 2020). In 2019-2020, walnut fruits (cv Lara) with anthracnose symptoms were collected from walnut orchards in Province of Venice (Northern Italy). Affected fruits showed necrotic and circular lesions with acervuli in the center causing the complete mummification of the fruit as described by Da Lio et al., 2018. Orange conidial masses appeared under wet conditions. The fungus was isolated from necrotic tissues and conidial masses were put on potato dextrose agar (PDA) medium. Plates were incubated at 25°C for 5 to 7 days. The colonies were white to pink on the upper side and pink with black spots on the reverse. Acervuli formed and produced conidial masses on PDA after 6 days. Culture and conidial morphology were in concordance with published descriptions of C. acutatum sensu lato (Damm et al., 2012). To confirm the identity, internal transcribed spacers (ITS), (glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT) and beta-tubulin (TUB2) genes were amplified and sequenced using the primer pairs ITS1/ITS4 (White at al. 1990), GDF1/GDR1 (Guerber et al., 2003), ACT512F/ACT783R and BT2Fd/BT4R primers (Da Lio et al., 2018). The isolates belonged to two different species of Colletotrichum acutatum complex: C. fioriniae (Marcelino & Gouli) and C. nymphaeae (Pass). Sequences of two representative isolates C. fioriniae CREADC-F2317 and C. nymphaeae CREADC-F2372 were deposited in GenBank with accession numbers MZ153170 and MZ191794 (ITS), MZ203522 and MZ224013 (GAPDH), MZ203521 and MZ224012 (ACT), and MZ203523 and MZ224014 (TUB2). For all the genes, isolates had a 100% similarity to multiple C. fioriniae and C. nymphaeae accessions, respectively. Maximum likelihood trees based on concatenated sequences of the four genes were constructed using MEGA 6.0 (Tamura et al., 2013). The phylogenetic analysis grouped the isolates in the C. fioriniae and nymphaeae clusters respectively. The two isolates CREADC-F2317 and CREADC-F2372 were used to confirm pathogenicity on walnut fruits. Fruits of cv Lara were surface disinfected by dipping in 3% NaOCl for 1 min, rinsed in sterile distilled water, and arranged in sterile humid chambers. Fruits were wounded with a sterile needle then inoculated with 20 μl of 106 conidia/ml suspensions of each isolate (one wound per fruit). Fruit treated with sterile distilled water served as a control. Inoculations were conducted on three fruits per replicate and three replicates per treatment arranged in a complete block randomized design. After 7 days incubation at 25 ± 1°C, all the inoculated fruits showed typical anthracnose symptoms and lesions with cream to salmon pink acervuli, whereas the controls remaied healthy. The species C. nymphaeae and C. fioriniae were reisolated from the rotted fruit. Pathogenicity tests were repeated twice with the same results. The morphology of the reisolated fungi was consistent with the inoculated one, fulfilling Koch's postulates. The species C. fioriniae and C. nymphaeae have been described affecting numerous species worldwide (Damm et al., 2012). C. fioriniae and C. nymphaeae have been previously reported to cause severe anthracnose on walnut, C. fioriniae in France (Da Lio et al., 2018) and Hungary (Varjas et al., 2019) and C. nymphaeae in France (Da Lio et al., 2018) and Brazil (Savian et al., 2019). To our knowledge, this is the first report of C. fioriniae and C. nymphaeae as causal agents of walnut anthracnose in Italy.
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Affiliation(s)
- Luongo Laura
- Cra-Plant Pathology Research, Via C.G. Bertero,22, Rome, Italy, Italy, 00156
- Italy;
| | | | | | | | - Salvatore Vitale
- Consiglio nazionale per la ricerca e la sperimentazione in agricoltura - Centro di Ricerca per la Patologia Vegetale (CRA-PAV), Via C. G. Bertero 22, Roma, Italy, 00156;
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Boufleur TR, Ciampi‐Guillardi M, Tikami Í, Rogério F, Thon MR, Sukno SA, Massola Júnior NS, Baroncelli R. Soybean anthracnose caused by Colletotrichum species: Current status and future prospects. Mol Plant Pathol 2021; 22:393-409. [PMID: 33609073 PMCID: PMC7938629 DOI: 10.1111/mpp.13036] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/04/2020] [Revised: 01/07/2021] [Accepted: 01/07/2021] [Indexed: 05/03/2023]
Abstract
Soybean (Glycine max) is one of the most important cultivated plants worldwide as a source of protein-rich foods and animal feeds. Anthracnose, caused by different lineages of the hemibiotrophic fungus Colletotrichum, is one of the main limiting factors to soybean production. Losses due to anthracnose have been neglected, but their impact may threaten up to 50% of the grain production. TAXONOMY While C. truncatum is considered the main species associated with soybean anthracnose, recently other species have been reported as pathogenic on this host. Until now, it has not been clear whether the association of new Colletotrichum species with the disease is related to emerging species or whether it is due to the undergoing changes in the taxonomy of the genus. DISEASE SYMPTOMS Typical anthracnose symptoms are pre- and postemergence damping-off; dark, depressed, and irregular spots on cotyledons, stems, petioles, and pods; and necrotic laminar veins on leaves that can result in premature defoliation. Symptoms may evolve to pod rot, immature opening of pods, and premature germination of grains. CHALLENGES As accurate species identification of the causal agent is decisive for disease control and prevention, in this work we review the taxonomic designation of Colletotrichum isolated from soybean to understand which lineages are pathogenic on this host. We also present a comprehensive literature review of soybean anthracnose, focusing on distribution, symptomatology, epidemiology, disease management, identification, and diagnosis. We consider the knowledge emerging from population studies and comparative genomics of Colletotrichum spp. associated with soybean providing future perspectives in the identification of molecular factors involved in the pathogenicity process. USEFUL WEBSITE Updates on Colletotrichum can be found at http://www.colletotrichum.org/. All available Colletotrichum genomes on GenBank can be viewed at http://www.colletotrichum.org/genomics/.
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Affiliation(s)
- Thais R. Boufleur
- Department of Plant Pathology and NematologyUniversity of São Paulo (USP), Luiz de Queiroz College of Agriculture (ESALQ)Piracicaba, São PauloBrazil
- Instituto Hispano‐Luso de Investigaciones Agrarias (CIALE)Universidad de SalamancaSalamancaSpain
| | - Maisa Ciampi‐Guillardi
- Department of Plant Pathology and NematologyUniversity of São Paulo (USP), Luiz de Queiroz College of Agriculture (ESALQ)Piracicaba, São PauloBrazil
| | - Ísis Tikami
- Department of Plant Pathology and NematologyUniversity of São Paulo (USP), Luiz de Queiroz College of Agriculture (ESALQ)Piracicaba, São PauloBrazil
| | - Flávia Rogério
- Department of Plant Pathology and NematologyUniversity of São Paulo (USP), Luiz de Queiroz College of Agriculture (ESALQ)Piracicaba, São PauloBrazil
| | - Michael R. Thon
- Instituto Hispano‐Luso de Investigaciones Agrarias (CIALE)Universidad de SalamancaSalamancaSpain
| | - Serenella A. Sukno
- Instituto Hispano‐Luso de Investigaciones Agrarias (CIALE)Universidad de SalamancaSalamancaSpain
| | - Nelson S. Massola Júnior
- Department of Plant Pathology and NematologyUniversity of São Paulo (USP), Luiz de Queiroz College of Agriculture (ESALQ)Piracicaba, São PauloBrazil
| | - Riccardo Baroncelli
- Instituto Hispano‐Luso de Investigaciones Agrarias (CIALE)Universidad de SalamancaSalamancaSpain
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Feng S, Fang H, Liu X, Dong Y, Wang Q, Yang KQ. Genome-wide identification and characterization of long non-coding RNAs conferring resistance to Colletotrichum gloeosporioides in walnut (Juglans regia). BMC Genomics 2021; 22:15. [PMID: 33407106 PMCID: PMC7789297 DOI: 10.1186/s12864-020-07310-6] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2020] [Accepted: 12/07/2020] [Indexed: 01/24/2023] Open
Abstract
BACKGROUND Walnut anthracnose caused by Colletotrichum gloeosporioides (Penz.) Penz. and Sacc. is an important walnut production problem in China. Although the long non-coding RNAs (lncRNAs) are important for plant disease resistance, the molecular mechanisms underlying resistance to C. gloeosporioides in walnut remain poorly understood. RESULTS The anthracnose-resistant F26 fruits from the B26 clone and the anthracnose-susceptible F423 fruits from the 4-23 clone of walnut were used as the test materials. Specifically, we performed a comparative transcriptome analysis of F26 and F423 fruit bracts to identify differentially expressed LncRNAs (DELs) at five time-points (tissues at 0 hpi, pathological tissues at 24 hpi, 48 hpi, 72 hpi, and distal uninoculated tissues at 120 hpi). Compared with F423, a total of 14,525 DELs were identified, including 10,645 upregulated lncRNAs and 3846 downregulated lncRNAs in F26. The number of upregulated lncRNAs in F26 compared to in F423 was significantly higher at the early stages of C. gloeosporioides infection. A total of 5 modules related to disease resistance were screened by WGCNA and the target genes of lncRNAs were obtained. Bioinformatic analysis showed that the target genes of upregulated lncRNAs were enriched in immune-related processes during the infection of C. gloeosporioides, such as activation of innate immune response, defense response to bacterium, incompatible interaction and immune system process, and enriched in plant hormone signal transduction, phenylpropanoid biosynthesis and other pathways. And 124 known target genes for 96 hub lncRNAs were predicted, including 10 known resistance genes. The expression of 5 lncRNAs and 5 target genes was confirmed by qPCR, which was consistent with the RNA-seq data. CONCLUSIONS The results of this study provide the basis for future functional characterizations of lncRNAs regarding the C. gloeosporioides resistance of walnut fruit bracts.
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Affiliation(s)
- Shan Feng
- College of Forestry, Shandong Agricultural University, Tai'an, 271018, Shandong Province, China
| | - Hongcheng Fang
- College of Forestry, Shandong Agricultural University, Tai'an, 271018, Shandong Province, China
- State Forestry and Grassland Administration Key Laboratory of Silviculture in the Downstream Areas of the Yellow River, Tai'an, 271018, Shandong Province, China
- Shandong Taishan Forest Ecosystem Research Station, Tai'an, 271018, Shandong Province, China
| | - Xia Liu
- College of Forestry, Shandong Agricultural University, Tai'an, 271018, Shandong Province, China
- Department of Science and Technology, Qingdao Agricultural University, Qingdao, 266109, Shandong Province, China
| | - Yuhui Dong
- College of Forestry, Shandong Agricultural University, Tai'an, 271018, Shandong Province, China
| | - Qingpeng Wang
- College of Forestry, Shandong Agricultural University, Tai'an, 271018, Shandong Province, China
| | - Ke Qiang Yang
- College of Forestry, Shandong Agricultural University, Tai'an, 271018, Shandong Province, China.
- State Forestry and Grassland Administration Key Laboratory of Silviculture in the Downstream Areas of the Yellow River, Tai'an, 271018, Shandong Province, China.
- Shandong Taishan Forest Ecosystem Research Station, Tai'an, 271018, Shandong Province, China.
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Cobo-Díaz JF, Baroncelli R, Le Floch G, Picot A. A novel metabarcoding approach to investigate Fusarium species composition in soil and plant samples. FEMS Microbiol Ecol 2020; 95:5513441. [PMID: 31183494 DOI: 10.1093/femsec/fiz084] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2019] [Accepted: 06/07/2019] [Indexed: 11/13/2022] Open
Abstract
The genus Fusarium contains more than 300 species, most of which are plant pathogens. Appropriate molecular tools for accurately and rapidly describing temporal and spatial shifts in Fusarium communities would be useful for the development of control strategies. Here, we present a new Fusarium-specific primer pair targeting the translation elongation factor 1-α (EF1α) gene with amplicons of ~430 bp, suitable for MiSeq metabarcoding sequencing. Mock Fusarium communities were used to evaluate its resolution and to optimize read filtering and downstream analyses. The use of the DADA2 pipeline coupled with operational taxonomic unit (OTU) picking at 98% similarity cut-off significantly increased the accuracy of read filtering. Building a phylogenetic tree using a manually curated database as a reference allowed taxonomic assignment at the species or species-complex level. This methodology was tested on soil and maize residue samples collected from crop fields. Up to 18 Fusarium OTUs, belonging to 17 species and 8 species complexes, were obtained, with F. oxysporum being the most abundant species in soil samples, while F. graminearum and F. avenaceum were the most abundant in maize residues. We demonstrated the high performance of this workflow which could be further used for profiling Fusarium species composition and dynamics during the cultivation cycle.
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Affiliation(s)
- José F Cobo-Díaz
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Université de Brest, EA 3882, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Riccardo Baroncelli
- Instituto Hispano-Luso de Investigaciones Agrarias (CIALE), University of Salamanca, Calle del Duero 12, 37185 Villamayor (Salamanca), Spain
| | - Gaétan Le Floch
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Université de Brest, EA 3882, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Adeline Picot
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, IBSAM, ESIAB, Université de Brest, EA 3882, Technopôle Brest-Iroise, 29280 Plouzané, France
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Wang QH, Fan K, Li DW, Han CM, Qu YY, Qi YK, Wu XQ. Identification, Virulence and Fungicide Sensitivity of Colletotrichum gloeosporioides s.s. Responsible for Walnut Anthracnose Disease in China. Plant Dis 2020; 104:1358-1368. [PMID: 32196416 DOI: 10.1094/pdis-12-19-2569-re] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [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: 05/27/2023]
Abstract
Walnut (Juglans regia L.) is an economically important woody nut and edible oil tree all over the world. However, walnut production is limited by walnut anthracnose, which is a disastrous disease that causes significant yield losses. Studying the etiology of anthracnose on walnut and the pathogens' virulence and sensitivities to fungicides would be beneficial for effective control. This study was conducted to identify the pathogen of walnut anthracnose and reveal the population diversity of pathogens through virulence, sensitivities to fungicides, and genetic variation. A total of 13 single-spore Colletotrichum isolates were collected from walnut anthracnose-diseased fruits and leaves from 13 walnut commercial orchards in Henan, Hubei, Shandong, and Shaanxi provinces in China. The isolates were identified as Colletotrichum gloeosporioides sensu stricto (s.s.) according to multilocus phylogenetic analyses (internal transcribed spacer, actin, glyceraldehyde-3-phosphate dehydrogenase, and chitin synthase), morphological as well as cultural characters, and pathogenicity. When the same walnut tissue was inoculated with different isolates, the disease lesion size was different. The results showed that the virulence of all isolates was considerably different, and the differences were not correlated with geographic origins. The virulence to walnut leaves and fruits inoculated with the same isolate was significantly different. Based on the virulence to walnut leaves and fruits, the 13 isolates were divided into three groups. Virulence of 69.2% of the isolates to walnut fruits was higher than that to leaves; 15.4% of isolates had no difference in pathogenicity, and the virulence to walnut leaves was higher for 15.4% of isolates. Tebuconazole, difenoconazole, flusilazole, and carbendazim inhibited the growth of fungal mycelia, and the concentration for 50% of maximal effect (EC50) values were 0.4 to 20.5, 0.6 to 2.6, 0.2 to 1.6, and 0.002 to 0.2 µg/ml, respectively, with average values of 6.5 ± 6.9, 1.5 ± 0.6, 0.9 ± 0.4, and 0.1 ± 0.05 µg/ml, respectively. All isolates were more sensitive to difenoconazole, flusilazole, and carbendazim than tebuconazole (P < 0.01). Isolate sensitivities to the same fungicide were different. Isolates SL-31 and TS-09 were the least sensitive to carbendazim and tebuconazole, respectively, and the resistance ratios were 87.3 and 51.6, respectively. Sensitivities to difenoconazole and flusilazole were largely consistent among all isolates, and the resistance ratios were from 1 to 4.6 and from 1 to 7, respectively. Therefore, difenoconazole and flusilazole could be chosen for disease control. The differences of pathogenicity and fungicide sensitivity were not correlated with geographic regions. These results indicated that there was high intraspecific diversity of populations in C. gloeosporioides s.s. that caused walnut anthracnose. For effective management, the targeted control strategy should be implemented based on the different geographic regions.
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Affiliation(s)
- Qing-Hai Wang
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
| | - Kun Fan
- Shandong Institute of Pomology, Taian, Shandong 271000, China
| | - De-Wei Li
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
- The Connecticut Agricultural Experiment Station Valley Laboratory, Windsor, CT 06095, U.S.A
| | - Chuan-Ming Han
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Yong-Yun Qu
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Yu-Kun Qi
- Shandong Provincial Academy of Forestry, Jinan, Shandong 250014, China
| | - Xiao-Qin Wu
- Co-Innovation Center for Sustainable Forestry in Southern China, College of Forestry, Nanjing Forestry University, Nanjing, Jiangsu 210037, China
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Chen S, Hu M, Schnabel G, Yang D, Yan X, Yuan H. Paralogous CYP51 Genes of Colletotrichum spp. Mediate Differential Sensitivity to Sterol Demethylation Inhibitors. Phytopathology 2020; 110:615-625. [PMID: 31799899 DOI: 10.1094/phyto-10-19-0385-r] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [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: 06/10/2023]
Abstract
Colletotrichum spp. isolates contain two paralogous CYP51 genes that encode sterol 14-demethylase enzymes; however, their role in sensitivity to demethylation inhibitor (DMI) fungicides is yet to be determined. In this study, each of the two genes from Colletotrichum fioriniae and C. nymphaeae was able to rescue the function of CYP51 in the yeast Saccharomyces cerevisiae, demonstrating their independent function. Deletion of CYP51A led to increased sensitivity to propiconazole, diniconazole, prothioconazole, cyproconazole, epoxiconazole, flutriafol, prochloraz, and difenoconazole in C. fioriniae, and to the same fungicides and tebuconazole in C. nymphaeae, with the exception of prochloraz. Deletion of CYP51B in C. fioriniae and CYP51B in C. nymphaeae made mutants increasingly sensitive to five of nine DMI fungicides tested. The results suggest species-specific, differential binding of DMI fungicides onto the two CYP51 enzymes. Pairing DMIs with different effects on CYP51A and -B deletion mutants resulted in synergistic effects, as determined in mycelial growth inhibition experiments. Deletion mutants showed no fitness penalty in terms of mycelial growth, sporulation, and virulence. Our study elucidates the effect of CYP51A and CYP51B of Colletotrichum spp. on DMI sensitivity, suggesting that using a mixture of DMIs may improve the efficacy for anthracnose management.
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Affiliation(s)
- Shuning Chen
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Mengjun Hu
- Department of Plant Science and Landscape Architecture, University of Maryland, College Park, MD 20742
| | - Guido Schnabel
- Department of Plant and Environmental Sciences, Clemson University, Clemson, SC 29634
| | - Daibin Yang
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Xiaojing Yan
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
| | - Huizhu Yuan
- Key Laboratory of Integrated Pest Management in Crops, Ministry of Agriculture, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China
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Pecchia S, Caggiano B, Da Lio D, Cafà G, Le Floch G, Baroncelli R. Molecular Detection of the Seed-Borne Pathogen Colletotrichum lupini Targeting the Hyper-Variable IGS Region of the Ribosomal Cluster. Plants (Basel) 2019; 8:E222. [PMID: 31337095 PMCID: PMC6681257 DOI: 10.3390/plants8070222] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2019] [Revised: 07/07/2019] [Accepted: 07/12/2019] [Indexed: 11/22/2022]
Abstract
Lupins anthracnose is a destructive seed and airborne disease caused by Colletotrichum lupini, affecting stems and pods. Primary seed infections as low as 0.01-0.1% can cause very severe yield losses. One of the most effective management strategies is the development of a robust and sensitive seed detection assay to screen seed lots before planting. PCR-based detection systems exhibit higher levels of sensitivity than conventional techniques, but when applied to seed tests they require the extraction of PCR-quality DNA from target organisms in backgrounds of saprophytic organisms and inhibitory seed-derived compounds. To overcome these limitations, a new detection protocol for C. lupini based on a biological enrichment step followed by a PCR assay was developed. Several enrichment protocols were compared with Yeast Malt Broth amended with ampicillin, streptomycin, and lactic acid were the most efficient. A species-specific C. lupini primer pair was developed based on rDNA IGS sequences. The specificity was evaluated against 17 strains of C. lupini, 23 different Colletotrichum species, and 21 different organisms isolated from seeds of Lupinus albus cv. Multitalia, L. luteus cv. Mister, and L. angustifolius cv. Tango. The protocol described here enabled the detection of C. lupini in samples artificially infected with less than 1/10,000 infected seed.
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Affiliation(s)
- Susanna Pecchia
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy.
| | - Benedetta Caggiano
- Department of Agriculture, Food and Environment, University of Pisa, Via del Borghetto 80, 56124 Pisa, Italy
| | - Daniele Da Lio
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, EA 3882, IBSAM, ESIAB, Université de Brest, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Giovanni Cafà
- CABI Europe-UK, Bakeham Lane, Egham, Surrey TW20 9TY, UK
| | - Gaetan Le Floch
- Laboratoire Universitaire de Biodiversité et Ecologie Microbienne, EA 3882, IBSAM, ESIAB, Université de Brest, Technopôle Brest-Iroise, 29280 Plouzané, France
| | - Riccardo Baroncelli
- Instituto Hispano-Luso de Investigaciones Agrarias (CIALE), University of Salamanca, Calle del Duero 12, 37185 Villamayor (Salamanca), Spain.
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