Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 142
Filtrar
Más filtros

Bases de datos
Tipo del documento
Intervalo de año de publicación
1.
Plant Dis ; 108(3): 599-607, 2024 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-37682223

RESUMEN

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.


Asunto(s)
Aminopiridinas , Fungicidas Industriales , Juglans , Maneb , Pirimidinas , Silanos , Estrobilurinas , Triazoles , Zineb , Fungicidas Industriales/farmacología , Nueces , Tiram , Filogenia , China
2.
Artículo en Inglés | MEDLINE | ID: mdl-36821367

RESUMEN

Three strains of a xerophilic Aspergillus species were isolated from house dust and honey in Japan. A molecular phylogenetic analysis based on the combined dataset for four regions (internal transcribed spacer rDNA, calmodulin, ß-tubulin, and RNA polymerase II second largest subunit) revealed that the strains formed an independent lineage, sister to Aspergillus halophilicus classified in section Restricti. Morphological comparisons show that the strains differ from A. halophilicus in three aspects: (i) the size of cleistothecia, as well as the surface structure and size of ascospores, (ii) the ability to grow on Harrold's agar and dichloran 18 % glycerol agar, and (iii) the lack of conidiophore formation on potato dextrose agar +20 % NaCl. These strains could be clearly distinguished from all known Aspergillus section Restricti species. Therefore, we consider it to be a novel species and propose the name Aspergillus verrucosus sp. nov. (NBRC 115547T).


Asunto(s)
Polvo , Miel , Análisis de Secuencia de ADN , Filogenia , Japón , Agar , ADN Espaciador Ribosómico/genética , ADN de Hongos/genética , Composición de Base , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Ácidos Grasos/química , Aspergillus
3.
Artículo en Inglés | MEDLINE | ID: mdl-37676702

RESUMEN

During a survey of species diversity of Penicillium and Talaromyces in sugarcane (Saccharum officinarum) rhizosphere in the Khuzestan province of Iran [1], 195 strains were examined, from which 187 belonged to Penicillium (11 species) and eight to Talaromyces (one species). In the present study, three strains of Penicillium belonging to section Exilicaulis series Restricta, identified as P. restrictum by Ansari et al. [1], were subjected to a phylogenetic study. The multilocus phylogeny of partial ß-tubulin, calmodulin and RNA polymerase II second largest subunit genes enabled the recognition of one new phylogenetic species that is here formally described as Penicillium rhizophilum sp. nov. This species is phylogenetically distinct in series Restricta, but it does not show significant morphological differences from other species previously classified in the series. Therefore, we here placed bias on the phylogenetic species concept. The holotype of Penicillium rhizophilum sp. nov. is IRAN 18169F and the ex-type culture is LA30T (=IRAN 4042CT=CBS 149737T).


Asunto(s)
Penicillium , Saccharum , Rizosfera , Irán , Filogenia , Análisis de Secuencia de ADN , ARN Ribosómico 16S/genética , ADN Bacteriano/genética , Técnicas de Tipificación Bacteriana , Composición de Base , Ácidos Grasos/química , Grano Comestible , Penicillium/genética
4.
Med Mycol ; 61(5)2023 May 01.
Artículo en Inglés | MEDLINE | ID: mdl-37070928

RESUMEN

This study looked for correlations between molecular identification, clinical manifestation, and morphology for Trichophyton interdigitale and Trichophyton mentagrophytes. For this purpose, a total of 110 isolates were obtained from Czech patients with various clinical manifestations of dermatophytosis. Phenotypic characters were analyzed, and the strains were characterized using multilocus sequence typing. Among the 12 measured/scored phenotypic features, statistically significant differences were found only in growth rates at 37 °C and in the production of spiral hyphae, but none of these features is diagnostic. Correlations were found between T. interdigitale and higher age of patients and between clinical manifestations such as tinea pedis or onychomychosis. The MLST approach showed that internal transcribed spacer (ITS) genotyping of T. mentagrophytes isolates has limited practical benefits because of extensive gene flow between sublineages. Based on our results and previous studies, there are few taxonomic arguments for preserving both species names. The species show a lack of monophyly and unique morphology. On the other hand, some genotypes are associated with predominant clinical manifestations and sources of infections, which keep those names alive. This practice is questionable because the use of both names confuses identification, leading to difficulty in comparing epidemiological studies. The current identification method using ITS genotyping is ambiguous for some isolates and is not user-friendly. Additionally, identification tools such as matrix-assisted laser desorption/ionization time-of-flight mass spectrometry fail to distinguish these species. To avoid further confusion and to simplify identification in practice, we recommend using the name T. mentagrophytes for the entire complex. When clear differentiation of populations corresponding to T. interdigitale and Trichophyton indotineae is possible based on molecular data, we recommend optionally using a variety rank: T. mentagrophytes var. interdigitale and T. mentagrophytes var. indotineae.


Species in the T. mentagrophytes complex lack support from usual taxonomic methods and simple identification tools are missing or inaccurate. To avoid recurring confusions, we propose naming the entire complex as T. mentagrophytes and optionally use rank variety to classify the observed variability.


Asunto(s)
Tiña , Animales , Filogenia , Tiña/diagnóstico , Tiña/veterinaria , Tipificación de Secuencias Multilocus/veterinaria , ADN Espaciador Ribosómico/genética , ADN Espaciador Ribosómico/química , Análisis de Secuencia de ADN/veterinaria , ADN de Hongos/genética , ADN de Hongos/química , Trichophyton , Fenotipo
5.
Plant Dis ; 2023 Nov 30.
Artículo en Inglés | MEDLINE | ID: mdl-38037207

RESUMEN

Pitaya, Hylocereus costaricensis, is a species of the Cactaceae family and originated in the Americas (Ortiz & Livera, 1995). It has been cultivated in Brazil and has shown a great potential for fruit production and is currently present in several markets (Faleiro et al. 2021). In July 2018, infected plants of pitaya with symptoms of anthracnose were obtained from an orchard in Fortaleza, Ceará Brazil, (3°44'24.5"S 38°34'30.8"W), with 50% disease incidence. The symptoms observed consisted of well-defined and depressed stains, that initially appeared as reddish-orange spots and were surrounded by a border of dark-brown color. As the lesion progressed, the center became light brown or whitish in color, with black dots appearing later. Four cladodes were collected with anthracnose symptoms. The pathogen was isolated from symptomatic cladodes, which were surface disinfected with 1% v/v NaClO and 70% v/v ethanol, rinsed with sterile distilled water, transferred onto potato dextrose agar (PDA) medium and incubated under a light/dark (12h/12h) photoperiod. Two isolates were recovered from the lesions on cladodes. Pure cultures were obtained from single conidia produced on colonies grown on PDA medium, using an inoculation needle under a microscope. Colonies on PDA exhibited white aerial mycelia with an orange conidial mass. The colonies were light grey in the front and light orange in the reverse of the plate. Morphological features suggested that the isolates had the same characteristics as previously described for Colletotrichum spp. (Weir et al., 2012). In order to identify the species of the isolates, the genomic DNA of UFCM 0684 and UFCM 0685 isolates was extracted using the CTAB method and the ITS region, TUB2, ACT, GS, GAPDH gene fragments were amplified. PCR products were sequenced and the resulting sequences were submitted to phylogenetic analyses based on maximum likelihood for the combination of the genes. The isolates grouped within Colletotrichum tropicale with 99% bootstrap support. The sequences obtained in this study were deposited in GenBank as ACT (accession no. OL799311, OL799312), TUB2 (OL799313; OL799314), GAPDH (OL799315, OL799316), GS (OL799317; OL799318) and ITS (OL799319; OL799320). After that, the UFCM 0685 isolate was selected to study for further characterization. Conidia (n = 50) were 13.7 (length) × 4.7 µm (width) in average, hyaline, aseptate and cylindrical. To complete Koch's postulates, pathogenicity tests were performed in moist chamber for one week at 25°C with 80% relative humidity on a 12 h fluorescent light/dark photoperiod. The cladodes were wounded using a sterilized needle and inoculated with 10 µl of a conidial suspension (1 × 106 conidia/ml) on three cladodes with five wounds each. The same number of uninoculated cladode was used as control. The experiment was performed twice. Two weeks later, all inoculated cladodes showed necrotic symptoms, which were similar to the symptoms previously observed in the field. The uninoculated cladode remained symptomless. The fungus was reisolated from the inoculated cladode and its morphological characteristics were similar to the original isolate. Colletotrichum tropicale has been reported to cause anthracnose on H. costaricensis in Mexico (Nunez-Garcia et al. 2023), H. undatus, H. monocanthus and H. megalanthus (Evallo et al. 2022). For the best of our knowledge, this is the first report of anthracnose caused by C. tropicale in H. costaricensis in Brazil.

6.
Plant Dis ; 2023 Feb 01.
Artículo en Inglés | MEDLINE | ID: mdl-36724035

RESUMEN

Liquidambar formosana Hance, a deciduous tree, is widely cultivated in China for its ornamental and afforestation value (Yin et al. 2021). In July 2019, leaf spot symptoms were observed with 20 to 30% disease incidence in Li shan forest farm (27°19'27.2″N, 115°32'51.08″E) in Ji'an city, Jiangxi province, China. Initial disease symptoms were small spots, which enlarged and circular to irregular, gray in the center, and dark brown to black circular on the lesion margin. Leaf pieces (5 × 5 mm) from the lesion borders were surfaced and sterilized in 70% ethanol for 30 s, followed by 2% NaOCl for 1 min, and then rinsed three times with sterile water (Si et al. 2022). Tissues were placed on potato dextrose agar (PDA) and incubated at 25°C. Pure cultures were obtained by monosporic isolation, and the representative isolates, FX-2, FX-5, and FX-9 were used for morphological studies and phylogenetic analyses. The colonies of three isolates on PDA grew fast, covering the entire plate with white cottony mycelia with black acervuli after 8 to 10 days. Conidia were 5-celled, clavate to fusiform, smooth, 19.6-24.2 × 6.2-8.5 µm (n = 100). The 3 median cells were dark brown to olivaceous, central cell was darker than other 2 cells, and the basal and apical cells were hyaline. All conidia developed one basal appendage (3.5-8.2 µm long; n = 100), and 2-3 apical appendages (18-31 µm long; n = 100), filiform. Morphological features were similar to Neopestalotiopsis sp. (Maharachchikumbura et al. 2014). The internal transcribed spacer (ITS) regions, ß-tubulin 2 (TUB2) and translation elongation factor 1-alpha (TEF1-α) were amplified from genomic DNA for the three isolates using primers ITS1/ITS4, T1/Bt-2b, EF1-728F/EF-2 (Maharachchikumbura et al. 2014), respectively. All sequences were deposited into GenBank (ITS, ON622512- ON622514; TUB2, ON676532 - ON676534; TEF1-α, ON676529 - ON676531). A maximum likelihood and Bayesian posterior probability analyses using IQtree v. 1.6.8 and Mr. Bayes v. 3.2.6 with the concatenated sequences placed FX-2, FX-5, and FX-9 in the clade of N. clavispora. Based on the multi-locus phylogeny and morphology, three isolates were identified as N. clavispora. To confirm pathogenicity, 10 healthy 2-year-old seedlings, and 5 leaves per seedling were wounded with a sterile needle (Φ=0.5 mm) and inoculated with 200 µL conidial suspension per leaf(106 conidia/mL). Ten control plants were inoculated with ddH2O. All the inoculated leaves were covered with plastic bags and kept in a greenhouse at 26 ± 2 °C and RH 70%. All the inoculated leaves showed similar symptoms to those observed in the field, whereas control leaves were asymptomatic for 8 days. N. clavispora was reisolated from the lesions, whereas no fungus was isolated from control leaves. N. clavispora can cuase leaf diseases in a variety of hosts, including × Taxodiomeria peizhongii (Zhang et al. 2022), Macadamia integrifolia (Qiu et al. 2020), Dendrobium officinale (Cao et al. 2022). N. cocoes, N. chrysea, Pestalotiopsis neglecta and P. neolitseae were also reported to infect L. formosana (Fan et al. 2021). However, this is the first report of N. clavispora infecting L. formosana in China. This work provided crucial information for epidemiologic studies and appropriate control strategies for this newly emerging disease.

7.
Mol Phylogenet Evol ; 166: 107310, 2022 01.
Artículo en Inglés | MEDLINE | ID: mdl-34506949

RESUMEN

The cell mouth is a property of the vast majority of free-living and endosymbiotic/epibiotic ciliates of the class Oligohymenophorea. Cytostome, however, naturally absents in the whole endosymbiotic subclass Astomatia and was naturally or experimentally lost in a few members of the subclass Hymenostomatia. This poses a question of how homoplastic might be the lack of oral structures in the oligohymenophorean evolution. To address this question, we used two mitochondrial genes, five nuclear markers, and detailed morphological data from an enigmatic mouthless ciliate, Clausilocola apostropha, which we re-discovered after more than half of a century. According to the present phylogenetic analyses, astomy evolved at least three times independently and in different time frames of the oligohymenophorean phylogeny, ranging from the Paleozoic to the Cenozoic period. Mouthless endosymbionts inhabiting mollusks (represented by Clausilocola), planarians (Haptophrya), and annelids ('core' astomes) never clustered together. Haptophrya grouped with the scuticociliate genus Conchophthirus, 'core' astomes were placed in a sister position to the scuticociliate orders Philasterida and Pleuronematida, and Clausilocola was robustly nested within the hymenostome family Tetrahymenidae. The tetrahymenid origin of Clausilocola is further corroborated by the existence of mouthless Tetrahymena mutants and the huge phenotypic plasticity in the cytostome size in tetrahymenids.


Asunto(s)
Cilióforos , Oligohimenóforos , Cilióforos/genética , Boca , Filogenia , Simbiosis/genética
8.
Microb Pathog ; 166: 105537, 2022 May.
Artículo en Inglés | MEDLINE | ID: mdl-35430269

RESUMEN

Anthracnose disease has harmed walnut in recent years, resulting in yield losses in China. As a results, both morphological and molecular techniques must be used to confirm the etiology of anthracnose on walnut. In May 2020, walnut branches with indications of anthracnose were gathered in Ganquan, China (N33°56'/E105°44'). A strain named JT20 was isolated and morphologically characterized as a Colletotrichum specie. Pathogenicity tests further confirmed that the strain caused apparent anthracnose symptoms on walnut which were consistent with those seen in the field. On PDA, colonies were gray, cotton wool-like on the surface and pale gray to pale orange on the dorsal side. Conidia were aseptate, hyaline, fusiform to cylindrical with rounded to pointy ends and a length of 5.52-9.30 × 2.18-4.61 µm. PDA, lactose, yeast extract, pH 6-8, temperature of 25 °C and complete darkness were shown to be the optimum culture conditions for surface mycelium growth while PSA, lactose, urea, pH 9, temperature of 30 °C and complete darkness were found to be the best conditions for pathogen sporulation. The isolate was deduced as based on phylogenetic analysis with 3 genes (ribosomal DNA-ITS, ACT and GAPDH) as well as morphological characteristics and cultural features, the isolate was identified C. nymphaeae. This is the first report of C. nymphaeae causing walnut anthracnose in China.


Asunto(s)
Colletotrichum , Juglans , Colletotrichum/genética , Lactosa , Filogenia , Enfermedades de las Plantas
9.
Stud Mycol ; 102: 95-132, 2022 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-36760462

RESUMEN

The Aspergillus series Nigri contains biotechnologically and medically important species. They can produce hazardous mycotoxins, which is relevant due to the frequent occurrence of these species on foodstuffs and in the indoor environment. The taxonomy of the series has undergone numerous rearrangements, and currently, there are 14 species accepted in the series, most of which are considered cryptic. Species-level identifications are, however, problematic or impossible for many isolates even when using DNA sequencing or MALDI-TOF mass spectrometry, indicating a possible problem in the definition of species limits or the presence of undescribed species diversity. To re-examine the species boundaries, we collected DNA sequences from three phylogenetic markers (benA, CaM and RPB2) for 276 strains from series Nigri and generated 18 new whole-genome sequences. With the three-gene dataset, we employed phylogenetic methods based on the multispecies coalescence model, including four single-locus methods (GMYC, bGMYC, PTP and bPTP) and one multilocus method (STACEY). From a total of 15 methods and their various settings, 11 supported the recognition of only three species corresponding to the three main phylogenetic lineages: A. niger, A. tubingensis and A. brasiliensis. Similarly, recognition of these three species was supported by the GCPSR approach (Genealogical Concordance Phylogenetic Species Recognition) and analysis in DELINEATE software. We also showed that the phylogeny based on benA, CaM and RPB2 is suboptimal and displays significant differences from a phylogeny constructed using 5 752 single-copy orthologous proteins; therefore, the results of the delimitation methods may be subject to a higher than usual level of uncertainty. To overcome this, we randomly selected 200 genes from these genomes and performed ten independent STACEY analyses, each with 20 genes. All analyses supported the recognition of only one species in the A. niger and A. brasiliensis lineages, while one to four species were inconsistently delimited in the A. tubingensis lineage. After considering all of these results and their practical implications, we propose that the revised series Nigri includes six species: A. brasiliensis, A. eucalypticola, A. luchuensis (syn. A. piperis), A. niger (syn. A. vinaceus and A. welwitschiae), A. tubingensis (syn. A. chiangmaiensis, A. costaricensis, A. neoniger and A. pseudopiperis) and A. vadensis. We also showed that the intraspecific genetic variability in the redefined A. niger and A. tubingensis does not deviate from that commonly found in other aspergilli. We supplemented the study with a list of accepted species, synonyms and unresolved names, some of which may threaten the stability of the current taxonomy. Citation: Bian C, Kusuya Y, Sklenár F, D'hooge E, Yaguchi T, Ban S, Visagie CM, Houbraken J, Takahashi H, Hubka V (2022). Reducing the number of accepted species in Aspergillus series Nigri. Studies in Mycology 102: 95-132. doi: 10.3114/sim.2022.102.03.

10.
Plant Dis ; 2022 Jul 11.
Artículo en Inglés | MEDLINE | ID: mdl-35815959

RESUMEN

Manglietia decidua Q. Y. Zheng is a deciduous broad-leaved plant and native to Jiangxi province, China. It is cultivated for its timber and urban landscaping (Xiong et al., 2014). In September 2019, a new foliar disease was observed on approx. 25% of 121 M. decidua trees in Jiangxi Agricultural University (N28°45'56″, E115°50'21″), Nanchang city, Jiangxi Province, China. The disease site belongs to the subtropical monsoon humid climate, with rainfall (1,600-1,700 mm) and red soil region. Initially, infection appeared on the leaf margins or tips as water-soaked, irregular lesions, then expanded to the center, developed into large black-brown, irregular necrotic lesions. Finally, the lesions fall off the leaves. To identify the pathogen, 15 diseased leaves were collected from 5 trees (3 leaves per tree) randomly. Small pieces (5 × 5 mm) cut from the lesion margins were surfaced sterilized (70% ethanol for 30 s, 3% NaOCl for 1 min, rinsed 3 times with sterile water), and placed on potato dextrose agar (PDA) at 25 °C. Among the isolated fungi, Colletotrichum-like colonies were about 91%, and 18 monoconidial isolates were obtained. Isolates HML-1, HML-4, and HML-7 were selected and preserved for further studies. Colonies on PDA were white, cottony, and grayish-white on the reverse side. Setae absent. Acervuli were brown, circular. Conidiophores were clear, septate, non-branching or branching at the base, conidiogenous cells were enteroblastic, phialidic, colorless, cylindrical, ampulliform. Conidia were elliptical, single-celled, straight, hyaline, and measured 13.3-17.9 × 4.3-5.7 µm (14.8 ± 1.2 × 4.8 ± 0.4 µm, n = 100). Appressoria were oval to irregular, dark brown, and ranged from 5.3-9.1 × 4.4-6.3 µm (7.2 ± 0.3 × 5.1 ± 0.2 µm, n=100). Morphological characteristics matched the description of Colletotrichum gloeosporioides sensu lato (Weir et al. 2012). The internal transcribed spacer regions (ITS), glyceraldehyde-3-phosphate dehydrogenase (GAPDH), actin (ACT), chitin synthase (CHS-1), calmodulin (CAL), and beta-tubulin 2 (TUB2) were sequenced (Weir et al., 2012), and deposited in GenBank (ITS: OL757565-OL757567; ACT: OL627398-OL627400; CHS-1: OL757358-OL757360; GAPDH: OL757361-OL757363; CAL: OL757355-OL757357; TUB2: OL757364-OL757366). Six loci were concatenated, and the aligned sequences (2056 bp) were 99.9%, 99.8% homologous to C. siamense ICMP 18574 and ex-type ICMP18578, respectively. In the maximum-likelihood phylogenetic tree, the highest log likehihood was -9259.74, and 3 isolates were in the C. siamense clade. Based on the phylogeny and morphology, 3 isolates were identified as C. siamense. The pathogenicity of 3 isolates was tested on 12 M. decidua plants (variety: Yi lin ke) grown in the field. Healthy leaves were wounded slightly with a needle (Φ=0.5 mm) and inoculated with 10 µL of spore suspension (106 conidia/mL). Controls were treated with ddH2O (Si et al. 2021). All the treated leaves were covered with plastic bags to keep a high-humidity environment for 2 days. The experiments were repeated twice. Within 9 days, all the inoculated points showed similar symptoms to those observed in the field, whereas controls were asymptomatic. The same isolate was re-isolated from the lesions, whereas no fungus was isolated from control leaves. Manglietia decidua is an ancient and endangered plant, threatened with southern blight (Sclerotium rolfsii) (Yi et al. 2021a), root rot (Calonectria ilicicola) (Yi et al. 2021b). This is the first report of the newly emerging disease caused by C. siamense in the world. The potential threat should be evaluated for conservation in the future. This study provided crucial information for epidemiological studies and appropriate control strategies.

11.
J Basic Microbiol ; 62(6): 689-700, 2022 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35099080

RESUMEN

Dragon fruit (Hylocereus polyrhizus) is an economically promising fruit in Bangladesh. The cultivation of dragon fruit has increased fourfold within a decade due to its popularity. Recently, a new disease known as stem canker was reported in some plantations of dragon fruit in Bangladesh, which forced some farmers to abandon their cultivation. This study aimed to explore the morphological, molecular, and cultural characteristics as well as host range of the causal agent associated with this destructive disease. Morphologically similar eight fungal isolates were recovered from eight canker symptomatic dragon fruit stems. Among them, two isolates (namely BU-DLa 01 and BU-DLa 02) were used for a detailed study. Morphological parameters and phylogeny of sequence data of internal transcribed spacer (ITS1, 5.8S rRNA, and ITS2), ß-tubulin, and translation elongation factor 1-α identified the isolates as Lasiodiplodia theobromae. The cultural features were studied hinged on the growth of the two isolates on various media, temperature, and pH. Though the mycelial growth of the fungi was supported by all the media tested, potato dextrose agar was the most suitable one for both isolates. The fungi thrived well at a temperature of 25-35°C and 5.5-6.5 pH. Inoculation trials of dragon fruit stem ascertained Koch's postulate. In host range test, the isolates were found pathogenic toward mango, guava, banana, and the fruits of dragon fruit. These data will contribute not only to understanding the biology of L. theobromae as a newly recognized pathogen of H. polyrhizus but also will help in designing a proper management package against this pathogen.


Asunto(s)
Cactaceae , Frutas , Ascomicetos , Características Culturales , Frutas/microbiología , Especificidad del Huésped , Enfermedades de las Plantas/microbiología
12.
Persoonia ; 48: 1-53, 2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38234691

RESUMEN

The genus Fusarium includes numerous important plant and human pathogens, as well as many industrially and commercially important species. During our investigation of fungal diversity in China, a total of 356 fusarioid isolates were obtained and identified from diverse diseased and healthy plants, or different environmental habitats, i.e., air, carbonatite, compost, faeces, soil and water, representing hitherto one of the most intensive sampling and identification efforts of fusarioid taxa in China. Combining morphology, multi-locus phylogeny and ecological preference, these isolates were identified as 72 species of Fusarium and allied genera, i.e., Bisifusarium (1), Fusarium (60), and Neocosmospora (11). A seven-locus dataset, comprising the 5.8S nuclear ribosomal RNA gene with the two flanking internal transcribed spacer (ITS) regions, the intergenic spacer region of the rDNA (IGS), partial translation elongation factor 1-alpha (tef1), partial calmodulin (cam), partial RNA polymerase largest subunit (rpb1), partial RNA polymerase second largest subunit (rpb2) gene regions, and partial ß-tubulin (tub2), were sequenced and employed in phylogenetic analyses. A genus-level phylogenetic tree was constructed using combined tef1, rpb1, and rpb2 sequences, which confirmed the presence of four fusarioid genera among the isolates studied. Further phylogenetic analyses of two allied genera (Bisifusarium and Neocosmospora) and nine species complexes of Fusarium were separately conducted employing different multi-locus datasets, to determine relationships among closely related species. Twelve novel species were identified and described in this paper. The F. babinda species complex is herein renamed as the F. falsibabinda species complex, including descriptions of new species. Sixteen species were reported as new records from China. Citation: Wang MM, Crous PW, Sandoval-Denis M, et al. 2022. Fusarium and allied genera from China: species diversity and distribution. Persoonia 48: 1-53. https://doi.org/10.3767/persoonia.2022.48.01.

13.
Persoonia ; 48: 203-218, 2022 Jul 12.
Artículo en Inglés | MEDLINE | ID: mdl-38234687

RESUMEN

Trichophyton erinacei is a main cause of dermatophytosis in hedgehogs and is increasingly reported from human infections worldwide. This pathogen was originally described in the European hedgehog (Erinaceus europaeus) but is also frequently found in the African four-toed hedgehog (Atelerix albiventris), a popular pet animal worldwide. Little is known about the taxonomy and population genetics of this pathogen despite its increasing importance in clinical practice. Notably, whether there are different populations or even cryptic species associated with different hosts or geographic regions is not known. To answer these questions, we collected 161 isolates, performed phylogenetic and population-genetic analyses, determined mating-type, and characterised morphology and physiology. Multigene phylogeny and microsatellite analysis supported T. erinacei as a monophyletic species, in contrast to highly incongruent single-gene phylogenies. Two main subpopulations, one specific mainly to Atelerix and second to Erinaceus hosts, were identified inside T. erinacei, and slight differences in the size of microconidia and antifungal susceptibilities were observed among them. Although the process of speciation into two lineages is ongoing in T. erinacei, there is still gene flow between these populations. Thus, we present T. erinacei as a single species, with notable intraspecies variability in genotype and phenotype. The data from wild hedgehogs indicated that sexual reproduction in T. erinacei and de novo infection of hedgehogs from soil are probably rare events and that clonal horizontal spread strongly dominates. The molecular typing approach used in this study represents a suitable tool for further epidemiological surveillance of this emerging pathogen in both animals and humans. The results of this study also highlighted the need to use a multigene phylogeny ideally in combination with other independent molecular markers to understand the species boundaries of dermatophytes. Citation: Cmoková A, Kolarík M, Guillot J, et al. 2022. Host-driven subspeciation in the hedgehog fungus, Trichophyton erinacei, an emerging cause of human dermatophytosis. Persoonia 48: 203-218. https://doi.org/10.3767/persoonia.2022.48.06.

14.
Med Mycol ; 59(4): 355-365, 2021 Apr 06.
Artículo en Inglés | MEDLINE | ID: mdl-32640011

RESUMEN

Arthroderma is the most diverse genus among dermatophytes encompassing species occurring in soil, caves, animal burrows, clinical material and other environments. In this study, we collected ex-type, reference and authentic strains of all currently accepted Arthroderma species and generated sequences of three highly variable loci (ITS rDNA, ß-tubulin, and translation elongation factor 1-α). The number of accepted species was expanded to 27. One novel species, A. melbournense (ex-type strain CCF 6162T = CBS 145858T), is described. This species was isolated from toenail dust collected by a podiatrist in Melbourne, during an epidemiological study of four geographical regions of Eastern Australia. Trichophyton terrestre, Chrysosporium magnisporum, and Chrysosporium oceanitis are transferred to Arthroderma. Typification is provided for T. terrestre that is not conspecific with any of the supposed biological species from the former T. terrestre complex, that is, A. insingulare, A. lenticulare and A. quadrifidum. A multi-gene phylogeny and reference sequences provided in this study should serve as a basis for future phylogenetic studies and facilitate species identification in practice. LAY ABSTRACT: The genus Arthroderma encompasses geophilic dermatophyte species that infrequently cause human and animal superficial infections. Reference sequences from three genetic loci were generated for all currently accepted Arthroderma species and phylogeny was constructed. Several taxonomic novelties are introduced. The newly provided data will facilitate species identification and future taxonomic studies.


Asunto(s)
Arthrodermataceae/clasificación , Arthrodermataceae/genética , ADN de Hongos/genética , Genes Fúngicos/genética , Filogenia , Australia , ADN Espaciador Ribosómico/genética , Humanos , Microsporum/clasificación , Microsporum/genética , Factor 1 de Elongación Peptídica/genética , Trichophyton/clasificación , Trichophyton/genética , Tubulina (Proteína)/genética
15.
Phytopathology ; 111(3): 509-520, 2021 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32880514

RESUMEN

Since 2006 there has been a decline in Colorado blue spruce (CBS; Picea pungens) planted as landscape trees and for Christmas tree production throughout the Lower Peninsula of Michigan. This decline is characterized by a slow loss of needles in the lower portion of the tree starting at branch tips, followed by entire branch dieback, which progresses upward over several years. This dieback has been linked to shallow branch cankers visible in the phloem when the bark layer is removed. Isolates in the fungal genus Diaporthe have been consistently isolated from lesion margins on symptomatic branches. Before the initial reports of declining CBS in landscape and Christmas trees, Diaporthe was known only as a nursery disease of CBS. To determine the species of Diaporthe linked to the decline of CBS in Michigan, seven gene regions were sequenced from a collection of Diaporthe isolates collected in 2011 through 2018 from CBS and other coniferous hosts. Subsequent phylogenetic analyses indicated that Diaporthe eres and a novel Diaporthe clade were present on symptomatic CBS in Michigan. The new species D. brevicancria nov. is described, and Koch's postulates were confirmed for D. brevicancria nov. and D. eres. D. brevicancria nov. produced the largest cankers in greenhouse pathogenicity trials, and dual inoculations of D. brevicancria nov. and D. eres produced intermediate cankers.


Asunto(s)
Picea , Ascomicetos , Colorado , Michigan , Filogenia , Enfermedades de las Plantas
16.
Stud Mycol ; 99: 100120, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-35003383

RESUMEN

Since the last revision in 2015, the taxonomy of section Flavipedes evolved rapidly along with the availability of new species delimitation techniques. This study aims to re-evaluate the species boundaries of section Flavipedes members using modern delimitation methods applied to an extended set of strains (n = 90) collected from various environments. The analysis used DNA sequences of three house-keeping genes (benA, CaM, RPB2) and consisted of two steps: application of several single-locus (GMYC, bGMYC, PTP, bPTP) and multi-locus (STACEY) species delimitation methods to sort the isolates into putative species, which were subsequently validated using DELINEATE software that was applied for the first time in fungal taxonomy. As a result, four new species are introduced, i.e. A. alboluteus, A. alboviridis, A. inusitatus and A. lanuginosus, and A. capensis is synonymized with A. iizukae. Phenotypic analyses were performed for the new species and their relatives, and the results showed that the growth parameters at different temperatures and colonies characteristics were useful for differentiation of these taxa. The revised section harbors 18 species, most of them are known from soil. However, the most common species from the section are ecologically diverse, occurring in the indoor environment (six species), clinical samples (five species), food and feed (four species), droppings (four species) and other less common substrates/environments. Due to the occurrence of section Flavipedes species in the clinical material/hospital environment, we also evaluated the susceptibility of 67 strains to six antifungals (amphotericin B, itraconazole, posaconazole, voriconazole, isavuconazole, terbinafine) using the reference EUCAST method. These results showed some potentially clinically relevant differences in susceptibility between species. For example, MICs higher than those observed for A. fumigatus wild-type were found for both triazoles and amphotericin B for A. ardalensis, A. iizukae, and A. spelaeus whereas A. lanuginosus, A. luppiae, A. movilensis, A. neoflavipes, A. olivimuriae and A. suttoniae were comparable to or more susceptible as A. fumigatus. Finally, terbinafine was in vitro active against all species except A. alboviridis.

17.
Plant Dis ; 105(11): 3510-3521, 2021 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-34010022

RESUMEN

Pears are one of the oldest and the third most important fruit species grown in temperate regions. They are consumed because of their nutritional and health benefits, in fresh form or as various processed products. This article resolves the etiology of the Penicillium-like mold symptoms on pear fruits in Serbia. Samples of pear fruits with blue mold and other Penicillium-like mold symptoms were collected in Serbia from 2016 to 2019, from four storages. The recovered isolates were identified and characterized according to a polyphasic approach. Morphological and physiological analyses were performed on three media and five temperatures, respectively. Four loci (internal transcribed spacer, beta-tubulin, calmodulin, and DNA-dependent RNA polymerase II second largest subunit) were used for sequencing, genetic identification, and phylogenetic analyses. The results of the identification by conventional and molecular methods were in agreement, and they revealed that the obtained isolates belong to five species: Penicillium crustosum, P. expansum, P. italicum, Talaromyces minioluteus, and T. rugulosus. In a pathogenicity test, P. crustosum, P. expansum, T. minioluteus, and T. rugulosus produced decay on artificially inoculated pear fruits, and P. italicum induced tissue response lesions. The results of this study are the first reports of T. minioluteus and T. rugulosus as postharvest pear pathogens. Also, these are the first world records of T. minioluteus, T. rugulosus, and P. italicum on fruits of European pear. Furthermore, this is the first finding of P. crustosum, P. expansum, P. italicum, T. minioluteus, and T. rugulosus on pear fruit in Serbia.


Asunto(s)
Penicillium , Pyrus , Talaromyces , Frutas , Penicillium/genética , Filogenia , Serbia , Talaromyces/genética
18.
Stud Mycol ; 95: 381-414, 2020 Mar.
Artículo en Inglés | MEDLINE | ID: mdl-32855743

RESUMEN

The Capnodiales, which includes fungi known as the sooty moulds, represents the second largest order in Dothideomycetes, encompassing morphologically and ecologically diverse fungi with different lifestyles and modes of nutrition. They include saprobes, plant and human pathogens, mycoparasites, rock-inhabiting fungi (RIF), lichenised, epi-, ecto- and endophytes. The aim of this study was to elucidate the lifestyles and evolutionary patterns of the Capnodiales as well as to reconsider their phylogeny by including numerous new collections of sooty moulds, and using four nuclear loci, LSU, ITS, TEF-1α and RPB2. Based on the phylogenetic results, combined with morphology and ecology, Capnodiales s. lat. is shown to be polyphyletic, representing seven different orders. The sooty moulds are restricted to Capnodiales s. str., while Mycosphaerellales is resurrected, and five new orders including Cladosporiales, Comminutisporales, Neophaeothecales, Phaeothecales and Racodiales are introduced. Four families, three genera, 21 species and five combinations are introduced as new. Furthermore, ancestral reconstruction analysis revealed that the saprobic lifestyle is a primitive state in Capnodiales s. lat., and that several transitions have occurred to evolve lichenised, plant and human parasitic, ectophytic (sooty blotch and flyspeck) and more recently epiphytic (sooty mould) lifestyles.

19.
Emerg Infect Dis ; 25(9): 1765-1768, 2019 09.
Artículo en Inglés | MEDLINE | ID: mdl-31441765

RESUMEN

Talaromyces marneffei and other Talaromyces species can cause opportunistic invasive fungal infections. We characterized clinical Talaromyces isolates from patients in California, USA, a non-Talaromyces-endemic area, by a multiphasic approach, including multigene phylogeny, matrix-assisted laser desorption/ionization time-of-flight mass spectrometry, and phenotypic methods. We identified 10 potentially pathogenic Talaromyces isolates, 2 T. marneffei.


Asunto(s)
Micosis/epidemiología , Talaromyces/aislamiento & purificación , Adulto , California/epidemiología , Humanos , Masculino , Micosis/microbiología , Filogenia , Talaromyces/genética
20.
Mol Phylogenet Evol ; 140: 106575, 2019 11.
Artículo en Inglés | MEDLINE | ID: mdl-31362084

RESUMEN

The diatom family Chaetocerotaceae (Bacillariophyta) is common in the marine plankton worldwide, especially in coastal areas and upwelling zones. Its defining character constitutes hollow processes, called setae, which emerge from the valves of the vegetative cells. The family comprises two extant genera: Bacteriastrum and Chaetoceros. Current systematics is based on morphological features of vegetative cells and resting spores and is summarised in a classification scheme subdividing Bacteriastrum in two sections, Isomorpha and Sagittata, and Chaetoceros in three subgenera: Hyalochaete, Chaetoceros (Phaeoceros) and Bacteriastroidea, and further into 22 sections. Phylogenies inferred from single molecular markers (18S and partial 28S rDNA) show only partial topological agreement and many poorly or unresolved basal ramifications. Since classification should not only satisfy practical needs but also reflect well-supported evolutionary relationships of the taxa under investigation, we inferred a multigene phylogeny of the family Chaetocerotaceae amplifying five genes of 100 strains encompassing six Bacteriastrum and 60 Chaetoceros species. We also compared the phylogenetic signal of nuclear, plastid and mitochondrial compartments to ascertain if the inferred tree topologies were congruent. Our results provided a robust multigene phylogeny of the family Chaetocerotaceae, offering a solid framework to test the validity of the traditional taxonomical classification. The genera Bacteriastrum and Chaetoceros were resolved as sister clades, whilst the subgenus Hyalochaete was found to be paraphyletic. Consequently, we rejected the subdivision in subgenera and only considered sections. Most of the already recognised sections were found to be monophyletic. We emended one section, rejected seven and erected three new ones. As a consequence of our proposed changes, all the sections investigated are supported by morphological and molecular characters alike. Thus, a natural classification is feasible for this important and very diverse marine planktonic family.


Asunto(s)
Diatomeas/clasificación , Filogenia , Animales , ADN Ribosómico/genética , Diatomeas/genética , Funciones de Verosimilitud , Especificidad de la Especie
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA