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Kevin D Hyde - One of the best experts on this subject based on the ideXlab platform.
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multigene phylogenetic characterisation of Colletotrichum artocarpicola sp nov from artocarpus heterophyllus in northern thailand
Phytotaxa, 2019Co-Authors: Chitrabhanu S Bhunjun, Ruvishika S Jayawardena, Deping Wei, Naruemon Huanraluek, Pranami D Abeywickrama, Rajesh Jeewon, Jutamart Monkai, Kevin D HydeAbstract:A new species, Colletotrichum artocarpicola, on Artocarpus heterophyllus from Chiang Rai, Thailand, is introduced using both morphological and molecular approaches. Combined phylogenetic analysis of ITS, GAPDH, CHS-1, ACT and TUB2 sequence data demonstrate that Colletotrichum artocarpicola is a distinct species within the gloeosporioides species complex. The new species is illustrated and compared with related taxa, and evidence of its pathogenicity is provided.
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a new species of Colletotrichum from sonchus sp in italy
Phytotaxa, 2017Co-Authors: Ruvishika S Jayawardena, Erio Camporesi, Abdallah M Elgorban, Ali H Bahkali, Jiye Yan, Kevin D HydeAbstract:Colletotrichum sonchicola , sp. nov . from Sonchus sp. (dandelion tribe) in Forli-Cesena Province, Italy, is introduced using morphological and molecular data. Combined phylogenetic analysis of ITS, GAPDH, CHS, ACT and TUB2 sequence data demonstrate that C. sonchicola is a distinct species within the dematium species complex. The new species is illustrated and compared with related taxa. This provides the first record of a Colletotrichum species from the genus Sonchus .
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life styles of Colletotrichum species and implications for plant biosecurity
Fungal Biology Reviews, 2017Co-Authors: Dilani D De Silva, Kevin D Hyde, P W Crous, Peter K Ades, Paul J TaylorAbstract:Colletotrichum is a genus of major plant pathogens causing anthracnose diseases in many plant crops worldwide. The genus comprises a highly diverse group of pathogens that infect a wide range of plant hosts. The life styles of Colletotrichum species can be broadly categorised as necrotrophic, hemibiotrophic, latent or quiescent and endophytic; of which hemibiotrophic is the most common. The differences in life style depend on the Colletotrichum species, the host species, the physiological maturity of the host and environmental conditions. Thus, the genus Colletotrichum provides a unique opportunity for analysing different life style patterns and features underlying a diverse range of plant–pathogen interactions. This review describes the various modes of life styles of Colletotrichum species, the underlying mechanisms of infection and colonisation, and implications the life styles have for plant biosecurity. Knowledge of life styles of Colletotrichum species will enable the development of improved diagnostics and application of integrated disease control methods to mitigate the risk of incursion of exotic Colletotrichum species.
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Endophytic species of Colletotrichum associated with mango in northeastern Brazil
Fungal Diversity, 2014Co-Authors: Willie A. S. Vieira, Sami J. Michereff, Kevin D Hyde, Marcos A. Morais, Marcos P. S. CâmaraAbstract:Endophytic species of Colletotrichum associated with Mangifera indica (mango) are poorly understood. In this study, Colletotrichum species were isolated from mango in Pernambuco State, Brazil. There were significant differences in isolation frequencies of Colletotrichum species among sites and plant tissues. Mature leaf blades were colonized by most Colletotrichum isolates at the majority of sites. Partial sequences of glyceraldehyde-3-phosphate dehydrogenase (GAPDH) of 97 Colletotrichum isolates were amplified as an initial measure of genetic diversity. Phylogenetic analysis with a subset of 22 isolates were performed based on a multi-locus dataset (ACT, TUB2, CAL, CHS-1, GAPDH, ITS) followed by Apn2/MAT IGS sequence-analysis for isolates within the C. gloeosporioides species complex. Molecular analysis associated with phenotypic characteristics revealed six previously described species [ C. asianum , C. cliviae , C. dianesei (syn. C. melanocaulon ), C. fructicola , C. karstii and C. tropicale ] and one new species. This new species is introduced as C. endomangiferae . All species isolated were pathogenic on mango fruits but varied in their virulence. There was no distribution pattern of species among sites and plant tissues, although C. asianum was the most prevalent species at all sites and in all plant tissues studied. Five previously reported Colletotrichum species causing anthracnose in mango fruits in northeastern Brazil were also recovered as endophytes.
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what are the common anthracnose pathogens of tropical fruits
Fungal Diversity, 2013Co-Authors: Dimuthu S Manamgoda, Dhanushka Udayanga, Xingzhong Liu, Ekachai Chukeatirote, Kevin D HydeAbstract:Species of Colletotrichum are associated with anthracnose of a wide range of host plants including cultivated and wild tropical fruits. The genetic and ecological diversity of species associated with wild fruits are poorly explored, as compared to those associated with pre and postharvest diseases of cultivated fruits. In the present study, isolates of Colletotrichum were obtained from commercially available cultivated fruits, wild fruits (from native trees in natural habitats) and a few herbaceous hosts collected in northern Thailand. These isolates were initially characterized based on analysis of complete sequences of nuclear ribosomal internal transcribed spacer (ITS), into the genetically defined species complexes of Colletotrichum gloeosporioides, C. acutatum, C. boninense and C. truncatum. The isolates were primarily identified in the C. gloeosporioides species complex, based on a strongly supported clade within the ITS gene tree and were further characterized using multi-gene phylogenetic analyses and morphology. Phylogenetic analyses of ITS, partial sequences of actin (ACT), calmodulin (CAL), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), glutamine synthetase (GS) and β-tubulin (TUB2) genetic markers were performed individually and in combination. Colletotrichum gloeosporioides sensu stricto was identified from lime (Citrus aurantifolia) and rose apple (Syzygium samarangense). Colletotrichum fructicola was isolated from dragon fruit (Hylocerous undatus) and jujube (Ziziphus sp.). Colletotrichum endophytica was found only from an unknown wild fruit. We observed a considerable genetic and host diversity of species occurring on tropical fruits within the clade previously known as Colletotrichum siamense sensu lato. The clade consists of isolates identified as pre and postharvest pathogens on a wide range of fruits, including coffee (Coffea arabica), custard apple (Annona reticulata), Cerbera sp., figs (Ficus racemosa) mango (Mangifera indica), neem (Azadirachta indica) and papaya (Carica papaya) and was the dominant group of species among most wild fruits studied. With the exception of one isolate from banana, which grouped in the C. siamense clade, all the other isolates were identified as Colletotrichum musae. A new species, Colletotrichum syzygicola, associated with Syzygium samarangense in Thailand, is introduced with descriptions and illustrations. This study highlights the need to re-assess the evolutionary relationships of Colletotrichum species occurring on cultivated and wild fruits with emphasis on their ecology and cryptic diversification including sampling at regional and global scales.
David E Wedge - One of the best experts on this subject based on the ideXlab platform.
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antifungal compounds from turmeric and nutmeg with activity against plant pathogens
Fitoterapia, 2014Co-Authors: Mohamed M Radwan, David E Wedge, Nurhayat Tabanca, Amer H Tarawneh, Stephen J CutlerAbstract:The antifungal activity of twenty-two common spices was evaluated against plant pathogens using direct-bioautography coupled Colletotrichum bioassays. Turmeric, nutmeg, ginger, clove, oregano, cinnamon, anise, fennel, basil, black cumin, and black pepper showed antifungal activity against the plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides. Among the active extracts, turmeric and nutmeg were the most active and were chosen for further investigation. The bioassay-guided fractionation led to the isolation of three compounds from turmeric (1-3) and three compounds from nutmeg (4-6). Their chemical structures were elucidated by spectroscopic analysis including HR-MS, 1D, and 2D NMR as curcumin (1), demethoxycurcumin (2) and bisdemethoxy-curcumin (3), erythro-(7R,8R)-Δ(8')-4,7-dihydroxy-3,3',5'-trimethoxy-8-O-4'-neolignan (4), erythro-(7R,8R)-Δ8'-7-acetoxy-3,4,3',5'-tetra-methoxy-8-O-4'-neolignan (5), and 5-hydroxy-eugenol (6). The isolated compounds were subsequently evaluated using a 96-well microbioassay against plant pathogens. At 30 μM, compounds 2 and 3 possessed the most antifungal activity against Phomopsis obscurans and Phomopsis viticola, respectively.
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characterization of volatile constituents of haplopappus greenei and studies on the antifungal activity against phytopathogens
Journal of Agricultural and Food Chemistry, 2006Co-Authors: Betul Demirci, K H C Baser, Nurhayat Tabanca, David E WedgeAbstract:Essential oil of Haplopappus greenei A. Gray was obtained by hydrodistillation of aerial parts, which were subsequently analyzed by gas chromatography and gas chromatography−mass spectrometry. Major components were identified as carvacrol (8.7%), β-pinene (7.6%), trans-pinocarveol (6.2%), and caryophyllene oxide (5.8%), respectively. In total, 104 components representing 84.9% of the investigated essential oil were characterized. Furthermore, the essential oil was evaluated for antimalarial, antimicrobial, and antifungal activities. However, only antifungal activity was observed against the strawberry anthracnose-causing fungal plant pathogens Colletotrichum acutatum, Colletotrichum fragariae, and Colletotrichum gloeosporioides using the direct overlay bioautography assay. Major essential oil components were also evaluated for antifungal activity; the carvacrol standard demonstrated nonselective activity against the three Colletotrichum species and the other compounds were inactive. Keywords: Haplopappus ...
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phytotoxic and fungitoxic activities of the essential oil of kenaf hibiscus cannabinus l leaves and its composition
Journal of Agricultural and Food Chemistry, 2001Co-Authors: Mozaina Kobaisy, Mario R Tellez, Charles L Webber, Franck E Dayan, Kevin K Schrader, David E WedgeAbstract:The chemical composition of the essential oil of kenaf (Hibiscus cannabinus) was examined by GC-MS. Fifty-eight components were characterized from H. cannabinus with (E)-phytol (28.16%), (Z)-phytol (8.02%), n-nonanal (5.70%), benzene acetaldehyde (4.39%), (E)-2-hexenal (3.10%), and 5-methylfurfural (3.00%) as the major constituents. The oil was phytotoxic to lettuce and bentgrass and had antifungal activity against Colletotrichum fragariae, Colletotrichum gloeosporioides, and Colletotrichum accutatum but exhibited little or no algicidal activity. Keywords: Kenaf; Hibiscus cannabinus; essential oil composition; fungi; algae; phytotoxicity; allelopathy
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Phytotoxic and fungitoxic activities of the essential oil of kenaf (Hibiscus cannabinus L.) leaves and its composition.
Journal of agricultural and food chemistry, 2001Co-Authors: Mozaina Kobaisy, Mario R Tellez, Charles L Webber, Franck E Dayan, Kevin K Schrader, David E WedgeAbstract:The chemical composition of the essential oil of kenaf (Hibiscus cannabinus) was examined by GC-MS. Fifty-eight components were characterized from H. cannabinus with (E)-phytol (28.16%), (Z)-phytol (8.02%), n-nonanal (5.70%), benzene acetaldehyde (4.39%), (E)-2-hexenal (3.10%), and 5-methylfurfural (3.00%) as the major constituents. The oil was phytotoxic to lettuce and bentgrass and had antifungal activity against Colletotrichum fragariae, Colletotrichum gloeosporioides, and Colletotrichum accutatum but exhibited little or no algicidal activity.
P W Crous - One of the best experts on this subject based on the ideXlab platform.
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high species diversity in Colletotrichum associated with citrus diseases in europe
Persoonia, 2017Co-Authors: Vladimiro Guarnaccia, P W Crous, J Z Groenewald, G PolizziAbstract:Species of Colletotrichum are considered important plant pathogens, saprobes, and endophytes on a wide range of plant hosts. Several species are well-known on citrus, either as agents of pre- or post-harvest infections, such as anthracnose, postbloom fruit drop, tear stain and stem-end rot on fruit, or as wither-tip of twigs. In this study we explored the occurrence, diversity and pathogenicity of Colletotrichum spp. associated with Citrus and allied genera in European orchards, nurseries and gardens. Surveys were carried out during 2015 and 2016 in Greece, Italy, Malta, Portugal and Spain. A total of 174 Colletotrichum strains were isolated from symptomatic leaves, fruits, petals and twigs. A multi-locus phylogeny was established based on seven genomic loci (ITS, GAPDH, ACT, CAL, CHS-1, HIS3 and TUB2), and the morphological characters of the isolates determined. Preliminary pathogenicity tests were performed on orange fruits with representative isolates. Colletotrichum strains were identified as members of three major species complexes. Colletotrichum gloeosporioides s.str. and two novel species (C. helleniense and C. hystricis) were identified in the C. gloeosporioides species complex. Colletotrichum karstii, C. novae-zelandiae and two novel species (C. catinaense and C. limonicola) in the C. boninense species complex, and C. acutatum s.str. was also isolated as member of C. acutatum species complex. Colletotrichum gloeosporioides and C. karstii were the predominant species of Colletotrichum isolated. This study represents the first report of C. acutatum on citrus in Europe, and the first detection of C. novae-zelandiae from outside New Zealand. Pathogenicity tests revealed C. gloeosporioides s.str. to be the most virulent species on fruits. The present study improves our understanding of species associated with several disease symptoms on citrus fruits and plants, and provides useful information for effective disease management.
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life styles of Colletotrichum species and implications for plant biosecurity
Fungal Biology Reviews, 2017Co-Authors: Dilani D De Silva, Kevin D Hyde, P W Crous, Peter K Ades, Paul J TaylorAbstract:Colletotrichum is a genus of major plant pathogens causing anthracnose diseases in many plant crops worldwide. The genus comprises a highly diverse group of pathogens that infect a wide range of plant hosts. The life styles of Colletotrichum species can be broadly categorised as necrotrophic, hemibiotrophic, latent or quiescent and endophytic; of which hemibiotrophic is the most common. The differences in life style depend on the Colletotrichum species, the host species, the physiological maturity of the host and environmental conditions. Thus, the genus Colletotrichum provides a unique opportunity for analysing different life style patterns and features underlying a diverse range of plant–pathogen interactions. This review describes the various modes of life styles of Colletotrichum species, the underlying mechanisms of infection and colonisation, and implications the life styles have for plant biosecurity. Knowledge of life styles of Colletotrichum species will enable the development of improved diagnostics and application of integrated disease control methods to mitigate the risk of incursion of exotic Colletotrichum species.
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species of the Colletotrichum acutatum complex associated with anthracnose diseases of fruit in brazil
Fungal Biology, 2016Co-Authors: Carlos Augusto Dorea Braganca, Riccardo Baroncelli, P W Crous, U Damm, Nelson Sidnei MassolaAbstract:Although Colletotrichum acutatum was recently investigated and shown to be a species complex comprising about 30 species, the name is still used in its broad sense for anthracnose pathogens of fruits in Brazil. In this study, a multilocus molecular analysis was carried out based on a dataset of ITS, HIS3, GAPDH, CHS-1, TUB2 and ACT sequences of Colletotrichum strains belonging to the C. acutatum species complex from fruits collected in different regions in Brazil combined with sequences of ex-type and other reference strains of species belonging to this complex. The strains were revealed to belong to Colletotrichum nymphaeae, Colletotrichum melonis, Colletotrichum abscissum and one new species, namely Colletotrichum paranaense, from apple and peach. Morphological descriptions of the new species and a strain closely related to but diverging from C. melonis are provided. From the data presently available, the most common species on apple fruits in Brazil is C. nymphaeae. In a pathogenicity test, strains of all four species caused lesions on detached apple, peach and guava fruits, except for strain CBS 134730 that did not infect guava fruits.
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Colletotrichum names in current use
Fungal Diversity, 2009Co-Authors: Kevin D Hyde, Lei Cai, P W Crous, U Damm, Paul F Cannon, Peter R Johnston, Jo Anne Crouch, P H Goodwin, Hang Chen, E B G JonesAbstract:Filamentous fungi in the genus Colletotrichum are destructive pathogens that cause disease and crop losses in plants worldwide. Taxonomy and nomenclature in the group is confusing, even to scientists working in the field, and inaccurate diagnosis of species is not uncommon. In this review, we provide a overview of the 66 Colletotrichum names that are in common use, and the 19 recently used names which are regarded as doubtful. This paper represents the first comprehensive overview of the genus in 17 years, and is the first summary treatment of Colletotrichum to incorporate data generated through DNA analysis and phylogenetic systematics. Species are listed alphabetically and annotated with their taxonomic entry, teleomorph, hosts and disease, brief summaries of taxonomic and phylogenetic research, and outstanding issues for the genus that are neccesary to stabilize species names. Sequence data and type culture collection resources are also summarized. The paper serves to provide a new starting point for usage of current names in Colletotrichum and indicates future work needed
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Colletotrichum species with curved conidia from herbaceous hosts
Fungal Diversity, 2009Co-Authors: U Damm, Paul F Cannon, J H C Woudenberg, P W CrousAbstract:Colletotrichum (Glomerellaceae, Sordariomycetes) species with dark setae and curved conidia are known as anthracnose pathogens of a number of economically important hosts and are often identified as C. dematium. Colletotrichum dematium has been synonymised with many species, including the type of the genus, C. lineola. Since there is no living strain of the original material of either species available, we re-collected C. lineola from the original location to serve as an epitype of that name, and chose an appropriate epitype specimen and associated strain of C. dematium from the CBS collection. A multilocus molecular phylogenetic analysis (ITS, ACT, Tub2, CHS-1, GAPDH, HIS3) of 97 isolates of C. lineola, C. dematium and other Colletotrichum species with curved conidia from herbaceous hosts resulted in 20 clades, with 12 clades containing strains that had previously been identified as C. dematium. The epitype strains of C. lineola and C. dematium reside in two closely related clades. Other clades represent four previously undescribed species, C. anthrisci, C. liriopes, C. rusci and C. verruculosum, isolated respectively from Anthriscus in the Netherlands, Liriope in Mexico, Ruscus in Italy and Crotalaria in Zimbabwe. The new combinations C. spaethianum and C. tofieldiae are made. Colletotrichum truncatum is epitypified, as well as C. circinans, C. curcumae and C. fructi. Three further unidentified Colletotrichum taxa were detected in the phylogenetic analysis, which may require description after further research. Each species is comprehensively described and illustrated
Helena Oliveira - One of the best experts on this subject based on the ideXlab platform.
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molecular and phenotypic analyses reveal association of diverse Colletotrichum acutatum groups and a low level of c gloeosporioides with olive anthracnose
Applied and Environmental Microbiology, 2005Co-Authors: Pedro Talhinhas, Surapareddy Sreenivasaprasad, Joao Nevesmartins, Helena OliveiraAbstract:Anthracnose (Colletotrichum spp.) is an important disease causing major yield losses and poor oil quality in olives. The objectives were to determine the diversity and distribution pattern of Colletotrichum spp. populations prevalent in olives and their relatedness to anthracnose pathogens in other hosts, assess their pathogenic variability and host preference, and develop diagnostic tools. A total of 128 Colletotrichum spp. isolates representing all olive-growing areas in Portugal and a few isolates from other countries were characterized by molecular and phenotypic assays and compared with reference isolates. Arbitrarily primed PCR data, internal transcribed spacer of rRNA gene and beta-tubulin 2 nucleotide sequences, colony characteristics, and benomyl sensitivity showed Colletotrichum acutatum to be dominant (>97%) with limited occurrence of Colletotrichum gloeosporioides (<3%). Among C. acutatum populations, five molecular groups, A2 to A6, were identified. A2 was widely prevalent (89%), coinciding with a high incidence of anthracnose and environmental conditions suitable to disease spread. A4 was dominant in a particular region, while other C. acutatum groups and C. gloeosporioides were sporadic in their occurrence, mostly related to marginal areas of olive cultivation. C. gloeosporioides, isolated from olive fruits with symptoms indistinguishable from those of C. acutatum, showed same virulence rating as the most virulent C. acutatum isolate from group A2. C. acutatum and C. gloeosporioides isolates tested in infected strawberry fruits and strawberry and lupin plants revealed their cross-infection potential. Diagnostic tools were developed from beta-tubulin 2 sequences to enable rapid and reliable pathogen detection and differentiation of C. acutatum groups.
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molecular and phenotypic analyses reveal association of diverse Colletotrichum acutatum groups and a low level of c gloeosporioides with olive anthracnose
Applied and Environmental Microbiology, 2005Co-Authors: Pedro Talhinhas, Surapareddy Sreenivasaprasad, Joao Nevesmartins, Helena OliveiraAbstract:Anthracnose (Colletotrichum spp.) is an important disease causing major yield losses and poor oil quality in olives. The objectives were to determine the diversity and distribution pattern of Colletotrichum spp. populations prevalent in olives and their relatedness to anthracnose pathogens in other hosts, assess their pathogenic variability and host preference, and develop diagnostic tools. A total of 128 Colletotrichum spp. isolates representing all olive-growing areas in Portugal and a few isolates from other countries were characterized by molecular and phenotypic assays and compared with reference isolates. Arbitrarily primed PCR data, internal transcribed spacer of rRNA gene and -tubulin 2 nucleotide sequences, colony characteristics, and benomyl sensitivity showed Colletotrichum acutatum to be dominant (>97%) with limited occurrence of Colletotrichum gloeosporioides (<3%). Among C. acutatum populations, five molecular groups, A2 to A6, were identified. A2 was widely prevalent (89%), coinciding with a high incidence of anthracnose and environmental conditions suitable to disease spread. A4 was dominant in a particular region, while other C. acutatum groups and C. gloeosporioides were sporadic in their occurrence, mostly related to marginal areas of olive cultivation. C. gloeosporioides, isolated from olive fruits with symptoms indistinguishable from those of C. acutatum, showed same virulence rating as the most virulent C. acutatum isolate from group A2. C. acutatum and C. gloeosporioides isolates tested in infected strawberry fruits and strawberry and lupin plants revealed their cross-infection potential. Diagnostic tools were developed from -tubulin 2 sequences to enable rapid and reliable pathogen detection and differentiation of C. acutatum groups. Several species belonging to the genus Colletotrichum cause important diseases in a wide range of crops including cereals, legumes, vegetables, and fruit crops. Olive (Olea europaea subsp. europaea) is an important crop in the Mediterranean basin, and olive anthracnose is becoming an increasingly important disease in this region. The disease is very common in Portugal, causing up to 100% losses, particularly in the widely cultivated variety Galega, but the disease is also spreading in other Mediterranean countries such as Spain (22), Italy (3), and Serbia and Montenegro (38). Symptoms typically occur on fruits at maturation under wet autumn conditions, as dark sunken lesions with abundant production of orange masses of conidia. Symptoms on stems and leaves are only rarely observed. The disease causes premature fruit drop, poor oil quality (high acidity), and damaged fruits unacceptable for canning. The olive anthracnose pathogen was originally described as Gloeosporium olivarum Alm. but was later transferred to Colletotrichum gloeosporioides (Penzig) Penzig & Saccardo (37). More recently, based on a limited collection of isolates, both Colletotrichum acutatum Simmonds ex Simmonds and C. gloeosporioides were reported to be associated with the disease (21). However, very little information is available on the relative importance of each of these species and their diversity and distribution. In anthracnose pathosystems, a number of examples are known where more than one Colletotrichum species is associated with the same host, and a single Colletotrichum species is able to infect a range of hosts (10). For example, C. acutatum is associated with the postbloom fruit drop and anthracnose of different types of citrus, while C. gloeosporioides is a postharvest pathogen of citrus but also occurs commonly as a saprophyte (4). So it is critical to be able to accurately diagnose the pathogen and understand its epidemiology to develop effective disease management. Moreover, differential sensitivity of these mixed Colletotrichum populations to fungicides such as benomyl can pose problems in disease control, as well as lead to shifts in pathogen populations (11). Molecular markers in conjunction with phenotypic analyses have been successfully applied to address these issues in various anthracnose pathosystems (2, 7, 34). The objectives of this work were (i) genotypic and phenotypic characterization of Colletotrichum spp. isolates associated with olive anthracnose to identify the key pathogen(s), (ii) to determine the extent of diversity and distribution of the pathogen(s), as well as their relatedness to Colletotrichum spp. populations from other hosts, (iii) to assess the pathogenic variability and cross-infection potential of these groups, and (iv) to develop tools for pathogen detection, as well as diagnosis of subspecific molecular groups, to facilitate improved disease management.
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genetic and morphological characterization of Colletotrichum acutatum causing anthracnose of lupins
Phytopathology, 2002Co-Authors: Pedro Talhinhas, Surapareddy Sreenivasaprasad, Joao Nevesmartins, Helena OliveiraAbstract:ABSTRACT Anthracnose, caused by Colletotrichum sp., is a serious problem of lupins (Lupinus spp.) worldwide. Morphological characters and molecular markers were used to characterize 43 Colletotrichum isolates from lupins, 8 isolates from other hosts, and 18 reference isolates representing related Colletotrichum spp., to assess the pathogen diversity and resolve its taxonomy. All lupin Colletotrichum isolates tested positive with C. acutatum-specific polymerase chain reaction (PCR) and did not test positive with C. gloeosporioides-specific PCR. Spore shape and colony diameter as well as insensitivity to benomyl grouped the lupin anthracnose isolates closer to C. acutatum than to C. gloeosporioides. Analysis of internal transcribed spacer (ITS) sequences of 57 Colletotrichum isolates grouped all lupin isolates with C. acutatum and distinct from C. gloeosporioides. Further, tub2 and his4 sequences revealed groups concordant with ITS, reducing the excessive dependence on the latter. Arbitrarily primed-PCR and amplified fragment length polymorphism analyses revealed intraspecific subgroups, but neither was useful to decipher species level relationships. ITS, tub2, and his4 results strongly support designating lupin anthracnose pathogen as C. acutatum or its subspecies. Most Colletotrichum isolates from lupins from worldwide locations are genetically homogeneous and form a distinct subgroup within C. acutatum. Present results also underline the potential of the C. acutatum-specific PCR for routine pathogen diagnosis.
Surapareddy Sreenivasaprasad - One of the best experts on this subject based on the ideXlab platform.
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Gene family expansions and contractions are associated with host range in plant pathogens of the genus Colletotrichum
BMC Genomics, 2016Co-Authors: Riccardo Baroncelli, Sabrina Sarrocco, Antonio Zapparata, Giovanni Vannacci, Daniel Buchvaldt Amby, Gaétan Le Floch, Richard J. Harrison, Eric B. Holub, Serenella A. Sukno, Surapareddy SreenivasaprasadAbstract:Many species belonging to the genus Colletotrichum cause anthracnose disease on a wide range of plant species. In addition to their economic impact, the genus Colletotrichum is a useful model for the study of the evolution of host specificity, speciation and reproductive behaviors. Genome projects of Colletotrichum species have already opened a new era for studying the evolution of pathogenesis in fungi. We sequenced and annotated the genomes of four strains in the Colletotrichum acutatum species complex (CAsc), a clade of broad host range pathogens within the genus. The four CAsc proteomes and secretomes along with those representing an additional 13 species (six Colletotrichum spp. and seven other Sordariomycetes) were classified into protein families using a variety of tools. Hierarchical clustering of gene family and functional domain assignments, and phylogenetic analyses revealed lineage specific losses of carbohydrate-active enzymes (CAZymes) and proteases encoding genes in Colletotrichum species that have narrow host range as well as duplications of these families in the CAsc. We also found a lineage specific expansion of necrosis and ethylene-inducing peptide 1 (Nep1)-like protein (NLPs) families within the CAsc. This study illustrates the plasticity of Colletotrichum genomes, and shows that major changes in host range are associated with relatively recent changes in gene content.
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molecular and phenotypic analyses reveal association of diverse Colletotrichum acutatum groups and a low level of c gloeosporioides with olive anthracnose
Applied and Environmental Microbiology, 2005Co-Authors: Pedro Talhinhas, Surapareddy Sreenivasaprasad, Joao Nevesmartins, Helena OliveiraAbstract:Anthracnose (Colletotrichum spp.) is an important disease causing major yield losses and poor oil quality in olives. The objectives were to determine the diversity and distribution pattern of Colletotrichum spp. populations prevalent in olives and their relatedness to anthracnose pathogens in other hosts, assess their pathogenic variability and host preference, and develop diagnostic tools. A total of 128 Colletotrichum spp. isolates representing all olive-growing areas in Portugal and a few isolates from other countries were characterized by molecular and phenotypic assays and compared with reference isolates. Arbitrarily primed PCR data, internal transcribed spacer of rRNA gene and -tubulin 2 nucleotide sequences, colony characteristics, and benomyl sensitivity showed Colletotrichum acutatum to be dominant (>97%) with limited occurrence of Colletotrichum gloeosporioides (<3%). Among C. acutatum populations, five molecular groups, A2 to A6, were identified. A2 was widely prevalent (89%), coinciding with a high incidence of anthracnose and environmental conditions suitable to disease spread. A4 was dominant in a particular region, while other C. acutatum groups and C. gloeosporioides were sporadic in their occurrence, mostly related to marginal areas of olive cultivation. C. gloeosporioides, isolated from olive fruits with symptoms indistinguishable from those of C. acutatum, showed same virulence rating as the most virulent C. acutatum isolate from group A2. C. acutatum and C. gloeosporioides isolates tested in infected strawberry fruits and strawberry and lupin plants revealed their cross-infection potential. Diagnostic tools were developed from -tubulin 2 sequences to enable rapid and reliable pathogen detection and differentiation of C. acutatum groups. Several species belonging to the genus Colletotrichum cause important diseases in a wide range of crops including cereals, legumes, vegetables, and fruit crops. Olive (Olea europaea subsp. europaea) is an important crop in the Mediterranean basin, and olive anthracnose is becoming an increasingly important disease in this region. The disease is very common in Portugal, causing up to 100% losses, particularly in the widely cultivated variety Galega, but the disease is also spreading in other Mediterranean countries such as Spain (22), Italy (3), and Serbia and Montenegro (38). Symptoms typically occur on fruits at maturation under wet autumn conditions, as dark sunken lesions with abundant production of orange masses of conidia. Symptoms on stems and leaves are only rarely observed. The disease causes premature fruit drop, poor oil quality (high acidity), and damaged fruits unacceptable for canning. The olive anthracnose pathogen was originally described as Gloeosporium olivarum Alm. but was later transferred to Colletotrichum gloeosporioides (Penzig) Penzig & Saccardo (37). More recently, based on a limited collection of isolates, both Colletotrichum acutatum Simmonds ex Simmonds and C. gloeosporioides were reported to be associated with the disease (21). However, very little information is available on the relative importance of each of these species and their diversity and distribution. In anthracnose pathosystems, a number of examples are known where more than one Colletotrichum species is associated with the same host, and a single Colletotrichum species is able to infect a range of hosts (10). For example, C. acutatum is associated with the postbloom fruit drop and anthracnose of different types of citrus, while C. gloeosporioides is a postharvest pathogen of citrus but also occurs commonly as a saprophyte (4). So it is critical to be able to accurately diagnose the pathogen and understand its epidemiology to develop effective disease management. Moreover, differential sensitivity of these mixed Colletotrichum populations to fungicides such as benomyl can pose problems in disease control, as well as lead to shifts in pathogen populations (11). Molecular markers in conjunction with phenotypic analyses have been successfully applied to address these issues in various anthracnose pathosystems (2, 7, 34). The objectives of this work were (i) genotypic and phenotypic characterization of Colletotrichum spp. isolates associated with olive anthracnose to identify the key pathogen(s), (ii) to determine the extent of diversity and distribution of the pathogen(s), as well as their relatedness to Colletotrichum spp. populations from other hosts, (iii) to assess the pathogenic variability and cross-infection potential of these groups, and (iv) to develop tools for pathogen detection, as well as diagnosis of subspecific molecular groups, to facilitate improved disease management.
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molecular and phenotypic analyses reveal association of diverse Colletotrichum acutatum groups and a low level of c gloeosporioides with olive anthracnose
Applied and Environmental Microbiology, 2005Co-Authors: Pedro Talhinhas, Surapareddy Sreenivasaprasad, Joao Nevesmartins, Helena OliveiraAbstract:Anthracnose (Colletotrichum spp.) is an important disease causing major yield losses and poor oil quality in olives. The objectives were to determine the diversity and distribution pattern of Colletotrichum spp. populations prevalent in olives and their relatedness to anthracnose pathogens in other hosts, assess their pathogenic variability and host preference, and develop diagnostic tools. A total of 128 Colletotrichum spp. isolates representing all olive-growing areas in Portugal and a few isolates from other countries were characterized by molecular and phenotypic assays and compared with reference isolates. Arbitrarily primed PCR data, internal transcribed spacer of rRNA gene and beta-tubulin 2 nucleotide sequences, colony characteristics, and benomyl sensitivity showed Colletotrichum acutatum to be dominant (>97%) with limited occurrence of Colletotrichum gloeosporioides (<3%). Among C. acutatum populations, five molecular groups, A2 to A6, were identified. A2 was widely prevalent (89%), coinciding with a high incidence of anthracnose and environmental conditions suitable to disease spread. A4 was dominant in a particular region, while other C. acutatum groups and C. gloeosporioides were sporadic in their occurrence, mostly related to marginal areas of olive cultivation. C. gloeosporioides, isolated from olive fruits with symptoms indistinguishable from those of C. acutatum, showed same virulence rating as the most virulent C. acutatum isolate from group A2. C. acutatum and C. gloeosporioides isolates tested in infected strawberry fruits and strawberry and lupin plants revealed their cross-infection potential. Diagnostic tools were developed from beta-tubulin 2 sequences to enable rapid and reliable pathogen detection and differentiation of C. acutatum groups.
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genetic and morphological characterization of Colletotrichum acutatum causing anthracnose of lupins
Phytopathology, 2002Co-Authors: Pedro Talhinhas, Surapareddy Sreenivasaprasad, Joao Nevesmartins, Helena OliveiraAbstract:ABSTRACT Anthracnose, caused by Colletotrichum sp., is a serious problem of lupins (Lupinus spp.) worldwide. Morphological characters and molecular markers were used to characterize 43 Colletotrichum isolates from lupins, 8 isolates from other hosts, and 18 reference isolates representing related Colletotrichum spp., to assess the pathogen diversity and resolve its taxonomy. All lupin Colletotrichum isolates tested positive with C. acutatum-specific polymerase chain reaction (PCR) and did not test positive with C. gloeosporioides-specific PCR. Spore shape and colony diameter as well as insensitivity to benomyl grouped the lupin anthracnose isolates closer to C. acutatum than to C. gloeosporioides. Analysis of internal transcribed spacer (ITS) sequences of 57 Colletotrichum isolates grouped all lupin isolates with C. acutatum and distinct from C. gloeosporioides. Further, tub2 and his4 sequences revealed groups concordant with ITS, reducing the excessive dependence on the latter. Arbitrarily primed-PCR and amplified fragment length polymorphism analyses revealed intraspecific subgroups, but neither was useful to decipher species level relationships. ITS, tub2, and his4 results strongly support designating lupin anthracnose pathogen as C. acutatum or its subspecies. Most Colletotrichum isolates from lupins from worldwide locations are genetically homogeneous and form a distinct subgroup within C. acutatum. Present results also underline the potential of the C. acutatum-specific PCR for routine pathogen diagnosis.