First Report of Pilidium concavum on Bergenia crassifolia in France

Bergenia crassifolia (L.) Fritsch (elephant's ears or Siberian tea) (Saxifragaceae) is a perennial rhizomatous plant with pink flowers appearing at the end of winter. Since 1990, large, brown, and necrotic spots have been observed on numerous B. crassifolia plants at the University of Sciences in Nice, France. Spots appeared each year in the spring on newly emerged leaves and enlarged up to 1 to 3 cm in diameter during the summer, sometimes affecting more than half of the leaf surface. Leaves with spots were collected from May to November and placed in a humid atmosphere. Black, sessile, discoid conidiomata developed on the spots and exuded a pink, then brown, spore mass. When a mass was transferred onto a 1% malt agar medium, mycelium grew and then numerous, relatively spherical conidiomata (0.5 to 2.5 mm in diameter) developed and exuded a pink slimy mass, which contained many conidia. The mycelium grown at 24°C in the dark was scarce and pale, pink-beige. Under the light, the fungal culture was much darker with a fluffy mycelium and numerous conidiomata. The base of the conidiomata was dark; conidiophores were hyaline and showed little segmentation. Unicellular, cylindrical, fusiform conidia were hyaline, 5.4 to 8 μm long, and 1.4 to 1.9 μm wide. The morphology and size of conidia were comparable with previous descriptions of Pilidium concavum (Desm.) Höhn. (2,3). The ITS1-5.8S-ITS2 region of two isolates was amplified by PCR with primers PN3 and PN10 according to Mendes-Pereira et al. (1) and sequenced. The 421-nt sequence (GenBank Accession No. FM211810) was 100% identical to that of the P. concavum specimen voucher BPI 1107275 (GenBank Accession No. AY487094). P. concavum was reported to be on stored or rotting leaves or fruits of many dicotyledonous plants (2). To validate Koch's postulates, pieces of mycelium cultures with conidiomata (28 days old) were placed onto the upper surface of leaves of healthy B. crassifolia plants (10 to 12 pieces per plant). The leaf epidermis was previously wounded with a needle and a drop of melted paraffin was poured onto each piece of mycelium to prevent desiccation. Agar plugs without the fungus were placed similarly on wounded leaves of two control plants. Four inoculated and two control plants were incubated in growth chambers at either 24 or 18°C (16 h of light per day, 15,000 lx, 80% humidity). At 24°C, brown spots developed from 90% of the inoculation sites, whereas spots were observed for only 18% of the sites at 18°C. Such spots did not develop on control plants. After 2 months, healthy leaves as well as those with necrotic spots were put in humid chambers. Conidiomata formed after 4 weeks and exuded the same pink mass, which contained numerous conidia and from which the fungus was reisolated. Similar symptoms were also observed in several other locations in France and in botanical gardens in Akureyri (Iceland) and Métis (Canada), from which P. concavum was reisolated. To our knowledge, this is the first report of P. concavum on B. crassifolia. References: (1) E. Mendes-Pereira et al. Mycol. Res. 107:1287, 2003. (2) M. E. Palm. Mycologia 83:787, 1991. (3) A. Y. Rossman et al. Mycol. Prog. 3:275, 2004.

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First Report of a Lasmenia sp. Causing Rachis Necrosis, Flower Abortion, Fruit Rot, and Leaf Spots on Rambutan in Puerto Rico

Plant Disease ◽

10.1094/pdis-05-11-0366 ◽

2011 ◽

Vol 95 (10) ◽

pp. 1313-1313 ◽

Cited By ~ 5

Author(s):

L. M. Serrato-Diaz ◽

L. I. Rivera-Vargas ◽

R. Goenaga ◽

G. J. M. Verkley ◽

R. D. French-Monar

Keyword(s):

Puerto Rico ◽

Plant Tissue ◽

Fruit Rot ◽

Conidial Suspension ◽

University Of Puerto Rico ◽

Tropical Fruit ◽

First Report ◽

Flower Abortion ◽

Necrotic Spots ◽

The University

Rambutan (Nephelium lappaceum L.) is a tropical fruit tree that has increased in importance for fruit growers in Puerto Rico. In 2008 and 2009, fruit rot and lesions on leaves and inflorescences were observed. A total of 276 diseased samples were collected from commercial orchards, orchards at the University of Puerto Rico, and the USDA-ARS in Mayaguez. Plant tissue was disinfested and plated on acidified potato dextrose agar (APDA). Besides other typical fungi associated with these tissue samples (2,3), 130 unknown isolates were identified as a Lasmenia sp. at the Fungal Biodiversity Centre (CBS), the Netherlands and the University of Puerto Rico using taxonomic keys (1,4). Sequencing of the rDNA with primers ITS 1 and ITS 4 and Lr5 and LR0R corresponding to the (internal transcribed spacer) ITS1-5.8S-ITS2 region and the partial region of the large ribosomal subunit (LSU), respectively, was completed. Five isolates (CBS 124122 to 124126) were deposited at the CBS. In APDA, colonies of a Lasmenia sp. were cream-colored with dark brown concentric rings and immersed, hyaline, branched, and septate mycelium. Acervuli were produced on APDA and plant tissue that was sampled from field and clean tissue that was inoculated with a Lasmenia sp. Conidia were 10 to 12 × 4 to 5 μm, light brown, thick walled, obclavate, aseptate, and the apex was obtuse with a scar at the base. Conidiophores were hyaline, septate, cylindrical, and sparingly branched. The conidiogenous cells were hyaline, cylindrical, and holoblastic. Pathogenicity tests were done on 12 healthy, superficially sterilized fruits under laboratory conditions, on four random leaves in each of six 6-month-old rambutan seedlings under greenhouse conditions, and on four flowers in six random inflorescences for each of six mature trees from an orchard. Tests were repeated. Either wounded or unwounded tissues were inoculated with a conidial suspension (2 to 4.5 × 106 conidia/ml) and 5-mm mycelial disks from each fungal isolate grown in APDA. After 5 days, a Lasmenia sp. produced necrotic spots on leaves, rachis necrosis and flower abortion, fruit rot, and water-soaked lesions on the fruit surface that spread to cause an aril (flesh) rot. Acervuli were produced on fruit spintems (hair-like appendages). Koch's postulates were fulfilled by reisolation of inoculated fungi from diseased tissue. A complete sequence for the ITS region for four isolates of a Lasmenia sp. was submitted to NCBI GenBank (Accession Nos. GU797405, GU797406, GU797407, and JF838336). Complete sequences of the LSU region for all five isolates were submitted to GenBank (Accession Nos. JF838337, JF838338, JF838339, JF838340, and JF838341). For both types of sequences, the identity was 100% between isolates. Although there is no DNA sequence data for the genus Lasmenia, a BLASTN search indicates a closer affinity to the Cryphonectriaceae (Diaporthales) (1). A Lasmenia sp. has been reported from Hawaii as causing fruit rot in rambutan (2). To our knowledge, this is the first report of a Lasmenia sp. causing rachis necrosis and flower abortion worldwide, and the first report of fruit rot and necrotic spots on leaves of rambutan in Puerto Rico. References: (1) M. N. Kamat et al. Rev. Mycol. 38:19, 1973. (2) K. A. Nishijima and P. A. Follett. Plant Dis. 86:71, 2002. (3) L. M. Serrato et al. Phytopathology (Abstr.) 100(suppl):S176, 2010. (4) B. C. Sutton. The Coelomycetes: Fungi Imperfecti with Pycnidia Acervuli and Stromata. CMI. Kew, Surrey, England, 1980.

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First Report of Rice Leaf Spot by Alternaria gaisen from Pakistan

Plant Disease ◽

10.1094/pdis-05-14-0477-pdn ◽

2014 ◽

Vol 98 (10) ◽

pp. 1440-1440

Author(s):

N. Akhtar ◽

R. Hafeez ◽

Z. A. Awan

Keyword(s):

Leaf Spot ◽

Pure Culture ◽

Spore Suspension ◽

Sodium Hypochlorite Solution ◽

Malt Extract ◽

Fungal Culture ◽

First Report ◽

Rice Leaf ◽

Morphological Studies ◽

Necrotic Spots

A rice field owned by an individual grower in Lahore, Pakistan, was surveyed in July 2013. Plants with symptoms of black, circular, necrotic spots 3 to 4 mm in diameter and an average of 8 to 10 spots per leaf were observed. Diseased plants were present in the field either singly or in groups of three to five. Ten symptomatic plants were selected randomly, and one infected leaf per plant and one necrotic spot per leaf was selected for the isolation of the pathogen. Necrotic areas were cut into small pieces, surface sterilized with 1% sodium hypochlorite solution, and plated on 2% malt extract agar (MEA) (Sigma, Dorset, UK). After incubation at 25 ± 2°C for 4 to 5 days, fungal mycelium was transferred aseptically to fresh MEA for pure culture. Three different isolates grown for 7 days on MEA were selected for detailed morphological studies. The fungal colony was dark greenish-black, reaching 7 to 8 cm in diameter, with 2 to 3 poorly defined growth rings. Conidiophores were geniculate and 50 to 140 × 3 to 4.5 μm in size. Conidia were in chains of 4 to 10, ovoid, ranging in size from 35 to 50 × 8 to 10 μm, with 12 to 15 transversal and 0 to 2 longitudinal septa. Conidia darkened from dull tan yellow to brown as the culture aged. Based on morphological characteristics, the pathogen was identified as Alternaria gaisen (2). A pure culture of the pathogen was deposited in First Fungal Culture Bank of Pakistan (FCBP1354). Due to the complexity of morphology-based identification of the genus Alternaria, sequencing of the internal transcribed spacer (ITS) region was carried out using the ITS1/ITS4 primer pair (1,3). The nucleotide sequence (KJ806190) of an amplified DNA fragment was compared with those already submitted to GenBank. The BLAST results revealed 99% identity of our A. gaisen isolate to strains NW680 (EU520123.1), FC3s (JX391937.1), and CBS 632.93 (KC584197.1), as well as some other A. gaisen strains. Pathogenicity testing of the fungus was performed on Basmati-198, a common cultivar of rice in Pakistan, by either spraying leaves of 1-month-old plants with 10 ml of spore suspension (2 × 105 spores/ml) or mixing this spore suspension in soil at the time of sowing. Control plants were sprayed with sterilized water. Plants were kept in a glasshouse at 30 ± 2°C and monitored for disease development. After 15 days of incubation, similar leaf necrotic spots to those observed in the field, developed on all inoculated plants, whereas all control plants remained healthy and asympomatic. The experiment was repeated three times and similar results were obtained. Re-isolation of A. gaisen from the symptomatic leaves fulfilled Koch's pathogenicity postulate. Although limited to the field where it was observed, to our best of knowledge, this is the first report of rice leaf spot by A. gaisen from Pakistan. Also, rice has not been reported as the host of A. gaisen from any part of the world. This study indicates that A. gaisen is potentially an important pathogen of rice plants. Further investigations into epidemiology and disease management strategies for this new disease are warranted especially where rice crop is grown extensively. References: (1) G. S. de Hoog and R. Horre. Mycoses 45:259, 2002. (2) E. G. Simmons. Alternaria: An identification manual. CBS, Fungal Biodiversity Center Utrecht, The Netherlands, 2007. (3) T. J. White et al. Page 315 in: PCR Protocols, A Guide to Methods and Applications, Academic Press, San Diego, 1990.

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First Report of Leaf Spot Caused by Phoma multirostrata on Fuchsia × hybrida in Italy

Plant Disease ◽

10.1094/pdis-94-3-0382a ◽

2010 ◽

Vol 94 (3) ◽

pp. 382-382 ◽

Cited By ~ 4

Author(s):

A. Garibaldi ◽

G. Gilardi ◽

M. L. Gullino

Keyword(s):

Leaf Surface ◽

Morphological Characteristics ◽

Its Region ◽

Northern Italy ◽

Pathogenicity Test ◽

First Report ◽

Plastic Bags ◽

Pathogenicity Tests ◽

Necrotic Spots ◽

Mycelial Suspension

Fuchsia × hybrida (Onagraceae) is widely used in gardens and very much appreciated as a potted plant. During the summer of 2008, a severe foliar disease was observed on 1- to 2-year-old plants in several gardens located near Biella (northern Italy). Small necrotic spots were observed on the upper and lower sides of infected leaves. Spots enlarged to form round areas of 2 to 12 mm in diameter and were well defined by a brown-purple margin at temperatures between 15 and 25°C. Severely infected leaves wilted and abscised as disease progressed. The disease occurred on 100% of the plants and at least 30% of the leaf surface was affected. Stems and flowers were not affected by the disease. A fungus was consistently isolated from infected leaves on potato dextrose agar amended with 25 mg/liter of streptomycin. The fungus was grown on leaf extract agar, including 30 g of autoclaved fuchsia leaves per liter, and maintained at 22°C (12-h light, 12-h dark). After 30 days, black pycnidia 150 to 450 μm in diameter developed, releasing abundant hyaline, elliptical, nonseptate conidia measuring 5.6 to 14.3 (10.3) × 1.9 to 5.6 (3.5) μm. On the basis of these morphological characteristics, the fungus was identified as a Phoma sp. (2). The internal transcribed spacer (ITS) region of rDNA of the isolate coded FuHy1 was amplified using primers ITS4/ITS6 (3) and sequenced. BLAST analysis (1) of the 488-bp segment obtained showed an E-value of 0.0 with Phoma multirostrata. The nucleotide sequence has been assigned GenBank Accession No. GU220539. Pathogenicity tests were performed by spraying leaves of healthy 6-month-old potted Fuchsia × hybrida plants with a spore and mycelial suspension (1 × 106 spores or mycelial fragments per milliliter). Noninoculated plants sprayed with water served as controls. Five plants were used for each treatment. Plants were covered with plastic bags for 5 days after inoculation and kept under greenhouse conditions at 20 to 24°C. Symptoms previously described developed on leaves 12 days after inoculation, whereas control plants remained healthy. The fungus was consistently reisolated from the lesions of the inoculated plants. The pathogenicity test was carried out twice. To our knowledge, this is the first report of the presence of P. multirostrata on fuchsia in Italy as well as worldwide. The importance of the disease is still limited in Italy. References: (1) S. F. Altschud et al. Nucleic Acids Res. 25:3389, 1997. (2) G. H. Boerema and G. J. Bollen. Persoonia 8:111, 1975. (3) D. E. L. Cooke and J. M. Duncan. Mycol. Res. 101:667, 1997.

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First Report of Pilidium concavum on Paeonia suffruticosa in China

Plant Disease ◽

10.1094/pdis-94-2-0271b ◽

2010 ◽

Vol 94 (2) ◽

pp. 271-271 ◽

Cited By ~ 2

Author(s):

Y. B. Duan ◽

Y. B. Kang ◽

Z. Z. Yu

Keyword(s):

Aerial Mycelium ◽

Causal Agent ◽

Its2 Region ◽

Paeonia Suffruticosa ◽

Humid Atmosphere ◽

First Report ◽

Leaf Spots ◽

Initial Symptoms ◽

Perennial Shrub ◽

Pure Cultures

Paeonia suffruticosa Andrews, a deciduous perennial shrub, is known for its beautiful and charming flowers. It is regarded as the flower symbol of China and cultivated throughout the country. Since 2006, large, brown necrotic spots have been observed on numerous P. suffruticosa plants in gardens in Luoyang, China. Spots appeared each year and were observed on more than 50% of the plants, sometimes affecting more than half of the leaf. Initial symptoms appeared as small, round, water-soaked lesions in the middle or on the margin of leaves. These areas enlarged up to 1 to 3 cm in diameter and were circular or irregular, brown to dark brown, and pale brown on the margins. In a humid atmosphere, black, sessile, discoid conidiomata developed on the spots and exuded a pink spore mass that turned brown with age. Conidiophores were hyaline, unicellular, cylindrical, and fusiform and 5.0 to 8.0 μm long and 1.4 to 2.0 μm wide. Pure cultures were obtained by plating the spores on potato dextrose agar (PDA) medium. In culture, the fungus produced a gray-to-brown colony with whitish aerial mycelium. The morphology and size of conidia were comparable with previous descriptions of Pilidium concavum (Desm.) Höhn. (1). The ITS1-5.8S-ITS2 region of the isolate was amplified by PCR with primers ITS1 and ITS4 and sequenced. The 472-nt sequence was 100% identical to that of the Pilidium concavum specimen voucher BPI 1107275 (GenBank Accession No. AY487094). To validate Koch's postulates, pathogenicity was tested by inoculating 10 leaves of P. suffruticosa with mycelia plugs from a colony growing on PDA; leaves inoculated with the plugs of PDA medium only served as the control. Leaves were covered with plastic for 24 h to maintain high relative humidity. After 7 days, 100% of the mycelium-inoculated leaves showed symptoms identical to those observed on P. suffruticosa leaves affected in the field, whereas all leaves inoculated with PDA medium only remained free of symptoms. Reisolation of the fungus from leaf lesions confirmed that the causal agent was Pilidium concavum. Thus, we concluded that Pilidium concavum is the causal agent of leaf spots of P. suffruticosa. This disease has been reported to be frequently occurring on P. suffruticosa stems imported from Japan (1), but to our knowledge, this is the first report of Pilidium concavum on P. suffruticosa in China. References: (1) M. E. Palm. Mycologia 83:787, 1991.

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Quercus canariensis, a New Host of Trabutia quercina

Plant Disease ◽

10.1094/pdis.2003.87.2.201b ◽

2003 ◽

Vol 87 (2) ◽

pp. 201-201 ◽

Cited By ~ 1

Author(s):

A. Trapero ◽

M. E. Sánchez

Keyword(s):

Leaf Surface ◽

New Host ◽

First Report ◽

Leaf Chlorosis ◽

Quercus Species ◽

Tar Spot ◽

Disease Survey ◽

Quercus Canariensis ◽

Thin Walled ◽

The University

Quercus canariensis Willd. is an oak species endemic to northwestern Africa and the Iberian Peninsula. This species is particularly abundant in the southwestern Andalucía Region of southern Spain. During a disease survey in this area from 1997 to 1998, we observed Q. canariensis trees affected by a tar spot disease. Tar spot lesions were clearly differentiated by a black, crustose, and shiny stromata (10 to 20 mm in diameter) on the upper surface of leaves mainly arranged along leaf veins but also scattered randomly over the leaf surface. On most leaves there was little necrosis, and on most trees the damage was not serious, although some trees located in the most humid areas were severely affected with leaf chlorosis and heavy defoliation. Other Quercus species in the area, such as Q. ilex and Q. suber, did not show signs of tar spot. One fungus species was consistently associated with tar spots. The fungus formed ascomata, 250 to 400 µm in diameter, embedded in the stromata. Asci were clavate or saccate, 45 to 55 × 17 to 22 µm, eight spored, and short stalked. The ascus apex was acute to obtuse. Ascospores were arranged irregularly, 20 to 25 (-30) × 5 to 8.5 µm, fusiform to ellipsoidal fusiform, often curved and flattened on one side, thin walled, hyaline, aseptate, and smooth without a gelatinous sheath or appendage. Based on these characteristics, the fungus was identified as Trabutia quercina (Rudolphi ex Fr.) Sacc. & Roum., a pathogen causing tar spot in several Quercus species in the Northern Hemisphere (1). Samples were deposited in the Plant Pathology Mycotheca at the University of Córdoba, Spain (MIC-888 to MIC-897). To our knowledge, this is the first report of T. quercina on Q. canariensis and the first report of this pathogen in Spain. Reference: (1) P. F. Cannon. Mycopathologia 135:69, 1996.

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First Report of Corynespora Leaf Spot Caused by C. cassiicola on Golden Vicary Privet (Ligustrum × vicaryi) in China

Plant Disease ◽

10.1094/pdis-11-12-1062-pdn ◽

2013 ◽

Vol 97 (8) ◽

pp. 1113-1113 ◽

Cited By ~ 2

Author(s):

S. H. Wang ◽

D. Zhao ◽

J. J. Gao

Keyword(s):

Leaf Spot ◽

Sequence Similarity ◽

Aqueous Suspension ◽

Morphological Characteristics ◽

Leaf Spot Disease ◽

Its2 Region ◽

Commonwealth Mycological Institute ◽

Corynespora Cassiicola ◽

Humid Atmosphere ◽

First Report

Golden vicary privet (Ligustrum × vicaryi Rehd.), a hybrid between L. ovalifolium ‘Aureum’ Rehd. and L. vulgare L., is widely used as a landscape shrub for horticultural ornamentation. From 2009 to 2011, a leaf spot disease of L. × vicaryi was observed in the parks in Luoyang, Henan Province, China. Lesions were initially brown and punctiform, and with age the lesions turned into elliptic, subcircular to irregular and pale brown, faintly zonate, and depressed. Fully mature lesions were mostly irregular to circular, 5 to 15 mm in diameter, centers tan to dark brown, with reddish brown to reddish purple margins of varying width. The disease eventually caused substantial premature defoliation. After infected leaves were collected from parks and maintained in a humid atmosphere, a layer of black mold developed on the surface of the lesions. Conidiophores were cylindrical, straight to slightly curved, brown, unbranched (2 to 7 septa), and were 98.5 to 403.9 μm in length, 4.5 to 6.6 μm in width. Conidia were solitary or in short chains containing two to five spores, and were cylindrical or obclavate, straight or flexuose (3 to 19 pseudosepta), pale olivaceous brown or brown when mature, and were 78.8 to 315.2 μm in length by 5.3 to 12.3 μm in width. Morphological characteristics of the fungus were similar to those of Corynespora cassiicola (Berk. & Curt.) Wei (1). Lesions on leaves were excised, surface sterilized, and plated on potato dextrose agar (PDA) and incubated at 25°C for 2 to 3 days. A fungus was isolated from the lesions, and pure isolates that were obtained after from single spored isolates were cultured on PDA. Colonies on PDA formed concentric growth rings, abundant aerial mycelia, and were grey or dark brown in color. The isolate ST1 was selected as a representative for molecular identification. The ITS1-5.8S-ITS2 region of the isolate was amplified by PCR with primers ITS1/ITS4 (3) and sequenced. BLAST analysis of the 559 bp amplicon (GenBank Accession No. KC138855) indicated 100% sequence similarity with C. cassiicola (GU138988) (2). To validate Koch's postulates, pathogenicity tests were performed by spraying leaves of five healthy potted L. vicaryi with a 106 conidia per ml aqueous suspension. Control plants were inoculated with sterile water. Plants were covered with plastic bags for 24 h after inoculation and maintained at 25°C. After 3 days, all inoculated plants showed typical symptoms, whereas water sprayed controls remained healthy. C. cassiicola was consistently reisolated from these lesions. The reisolated conidia showed the same morphological characteristics as described above. To our knowledge, this is the first report of leaf spot caused by C. cassiicola on L. × vicaryi in China. Its confirmation is a significant step toward management recommendations for growers. References: (1) M. B. Ellis et al. Corynespora cassiicola. CMI Descriptions of Pathogenic Fungi and Bacteria, no. 303. Commonwealth Mycological Institute, Kew, UK, 1971. (2) X. B. Liu et al. Plant Dis. 94:916, 2010. (3) T. J. White et al. Page 315 in: PCR Protocols: A Guide to Methods and Applications. Academic Press, San Diego, 1990.

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Molecular Detection of Filamentous Fungi in Formalin-Fixed Paraffin-Embedded Specimens in Invasive Fungal Wound Infections Is Feasible with High Specificity

Journal of Clinical Microbiology ◽

10.1128/jcm.01259-19 ◽

2019 ◽

Vol 58 (1) ◽

Cited By ~ 3

Author(s):

Anuradha Ganesan ◽

Justin Wells ◽

Faraz Shaikh ◽

Philip Peterson ◽

William Bradley ◽

...

Keyword(s):

Filamentous Fungi ◽

Rapid Identification ◽

Lower Sensitivity ◽

Its2 Region ◽

Fungal Culture ◽

Wound Infections ◽

Formalin Fixed Paraffin ◽

Formalin Fixed Paraffin Embedded ◽

Panfungal Pcr ◽

Formalin Fixed

ABSTRACT Trauma-related invasive fungal wound infections (IFIs) are associated with significant morbidity and mortality. Early identification and treatment are critical. Traditional identification methods (e.g., fungal cultures and histopathology) can be delayed and insensitive. We assessed a PCR-based sequencing assay for rapid identification of filamentous fungi in formalin-fixed paraffin-embedded (FFPE) specimens obtained from combat casualties injured in Afghanistan. Blinded FFPE specimens from cases (specimens positive on histopathology) and controls (specimens negative on histopathology) were submitted for evaluation with a panfungal PCR. The internal transcribed spacer 2 (ITS2) region of the fungal ribosomal repeat was amplified and sequenced. The PCR results were compared with findings from histopathology and/or culture. If injury sites contributed multiple specimens, findings for the site were collapsed to the site level. We included 64 case subjects (contributing 95 sites) and 102 controls (contributing 118 sites). Compared to histopathology, panfungal PCR was specific (99%), but not as sensitive (63%); however, sensitivity improved to 83% in specimens from sites with angioinvasion. Panfungal PCR identified fungi of the order Mucorales in 33 of 44 sites with angioinvasion (75%), whereas fungal culture was positive in 20 of 44 sites (45%). Saksenaea spp. were the dominant fungi identified by PCR in specimens from angioinvasion sites (57%). Panfungal PCR is specific, albeit with lower sensitivity, and performs better at identifying fungi of the order Mucorales than culture. DNA sequencing offers significant promise for the rapid identification of fungal infection in trauma-related injuries, leading to more timely and accurate diagnoses.

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First report of Gibellulopsis nigrescens on peppermint in Germany

Journal of Plant Diseases and Protection ◽

10.1007/s41348-021-00540-0 ◽

2021 ◽

Author(s):

Elias Alisaac ◽

Monika Götz

Keyword(s):

Verticillium Wilt ◽

Elongation Factor ◽

Economic Losses ◽

Fungal Culture ◽

Translation Elongation ◽

First Report ◽

Regular Control ◽

Fungal Dna ◽

Elongation Factor 1 ◽

Important Medicinal Plant

AbstractPeppermint is an important medicinal plant, and it is known for its essential oils and phenolic acids. Verticillium wilt is a vascular disease resulted from several Verticillium spp. causing significant economic losses in peppermint cultivation. In this study, the fungus Gibellulopsis nigrescens (syn. Verticillium nigrescens) was isolated from symptomless peppermint plants during the regular control of Verticillium wilt on peppermint in Germany. A pure fungal culture was prepared, and fungal DNA was extracted. Ribosomal internal transcribed spacer (ITS), beta-tubulin (TUB), and translation elongation factor 1-α (TEF1-α) were amplified, sequenced, and deposited in the GenBank. These sequences are located within the Gibellulopsis nigrescens cluster. Koch’s postulate was fulfilled, and the fungus was re-isolated from the inoculated plants. Up to our knowledge, this is the first report of Gibellulopsis nigrescens on peppermint in Germany.

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First report of Berkeleyomyces basicola causing mango root rot and decline in India

Plant Disease ◽

10.1094/pdis-10-20-2133-pdn ◽

2020 ◽

Author(s):

Prabhat Kumar Shukla ◽

Tahseen Fatima ◽

Nidhi Kumari

Keyword(s):

Root Rot ◽

Fungal Pathogens ◽

Mangifera Indica ◽

Uttar Pradesh ◽

Its2 Region ◽

Mature Trees ◽

Ceratocystis Fimbriata ◽

First Report ◽

Rdna Its2 ◽

Mango Tree

Mango wilt has been a serious constraint in mango (Mangifera indica L.) production in several countries including India (Shukla et al. 2018). Although, several fungal pathogens have been reported associated with the disease, species of Ceratocystis, Verticillium and Lasiodiplodia have been found predominantly responsible for the wilt (Shukla et al. 2018). A twenty-seven-year old mango tree cv. Dashehari at Rehmankhera, Lucknow, Uttar Pradesh, India suffered sudden wilt (Fig. 1A) during February 2020. Though, symptoms were similar to Ceratocystis wilt, no gummosis was observed on trunk or branches which occurred in the majority of Ceratocystis fimbriata infected trees. The infected roots of the wilted tree exhibited dark brown to black discoloration in woody portions (Fig. 1B). Severely affected roots were completely rotten. Similar symptoms of root infection were observed in an additional 16 declining trees within an orchard of 120 trees total (Fig. 2). The infected hard wood samples from live roots of 16 declining and one wilted trees were utilized for isolation by placing stem tissue of discolored and normal colored tissue on surface sterilized fresh carrot discs placed in a moisture chamber (Fig. 1C) for 10 days. Out of 17 tree samples, isolates of Berkeleyomyces basicola (Berk. & Broome) W.J. Nel, Z.W. de Beer, T.A. Duong, M.J. Wingf. (Nel et al. 2018) obtained from 1 wilted and 9 declining trees were transferred to and maintained in pure culture on potato dextrose agar. Isolates were grown for 7 to 10 days at 23±1 °C temperature in the dark. The isolates were characterized by a greyish black compact mycelial colony (Fig. 1D). Two types of spores, endoconidia (phialospores) and chlamydospores (aleuriospores or amylospores) were observed under microscope. The endoconidia were hyaline, cylindrical in shape with 10 to 42 × 3 to 6 μm (n=50) in size (Fig. 1E). Chains of dark colored chlamydospores (3 to 7 spores in chain) of 24 to 52 × 10 to 12 μm (n=50) size were apparent (Fig. 1E&F). Molecular identification of the fungus isolated from the wilted tree was established by amplifying the ITS1-5.8 rDNA-ITS2 region of fungal genomic DNA and the set of ITS primers (ITS 1 and ITS4) (White et al. 1990) followed by sequencing. The sequence has been submitted to the NCBI database vide accession number MT786402. The present isolate (MT786402) shared >99 percent nucleotide similarity with other B. basicola isolates. The phylogenetic tree was constructed using the ITS1-5.8 rDNA-ITS2 sequences of other B. basicola isolates and other Thielaviopsis spp., C. fimbriata, Chalaropsis thielavioides through neighbor joining method using MEGAX software (Fig. 3) (Kumar et al. 2018). The present isolate formed a distinct cluster along with other B. basicola isolates in a separate clade. Koch's postulate was performed under a transparent polycarbonate sheet roof net house at 14.4 and 42.2 °C minimum and maximum temperatures, respectively. A 100 ml macerated culture suspension consisting of 1000 chlamydospores and endoconidia per ml suspension was inoculated in the rhizosphere of mango seedlings planted in sterilized soil filled in earthen pots, using ten replicates for inoculated and uninoculated plants. Symptoms of necrotic root tissue were observed 90 days after inoculation and were consistent with those observed in the field. The same fungus was re-isolated from infected roots and identity was confirmed. All control plants remained symptom-free and B. basicola was not isolated from the roots. Thus, we conclude that B. basicola is capable of causing root rot disease of mango. To the best of our knowledge this is the first report of B. basicola causing mango root rot and decline across the globe, hitherto unreported. The extent of the root necrosis symptoms associated with mature mango trees demonstrates the potential virulence of B. basicola, although its pathogenicity risk on healthy mature trees is still unknown. However, the possibility of severe losses to the mango industry in world number one mango producer country, India cannot be ruled out, if found widespread.

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First Report of Stigmina palmivora Causing Leaf Spots on Phoenix roebelenii in Brazil

Plant Disease ◽

10.1094/pdis-10-13-1030-pdn ◽

2014 ◽

Vol 98 (6) ◽

pp. 849-849 ◽

Cited By ~ 1

Author(s):

A. Colmán ◽

R. A. da Silva ◽

R. Alves ◽

M. Silva ◽

R. W. Barreto

Keyword(s):

Pure Culture ◽

Leaf Surface ◽

The United States ◽

Culture Collection ◽

Commonwealth Mycological Institute ◽

First Report ◽

Leaf Spots ◽

Nucleotide Homology ◽

Query Coverage ◽

Representative Samples

Phoenix roebelenii (Arecaceae), known as dwarf date (tamareira-anã in Brazil), is a palm native to Southeast Asia and widely cultivated worldwide because of its ornamental value and ease of adaptation to a broad range of climates and soil types (4). In June 2012, some individuals were observed in a private garden in the municipality of Viçosa (state of Minas Gerais, Brazil) bearing numerous necrotic lesions on its leaves. Representative samples were taken, dried in a plant press, and brought to the laboratory for examination. A fungus was regularly associated with the leaf spots. Fungal structures were mounted in lactophenol and slides were examined under a microscope (Olympus BX 51). Spores were taken from sporulating colonies with a sterile fine needle and plated on PDA for isolation. A pure culture was deposited in the culture collection of the Universidade Federal de Viçosa (accession COAD1338). A dried herbarium sample was deposited in the local herbarium (VIC39741). The fungus had the following morphology: conidiophores grouped on sporodochia, cylindrical, 12 to 29 × 5 to 6 μm, dark brown; conidiogenous cells, terminal, proliferating percurrently (annellidic), 8 to 20 × 5 to 6 μm, pale to dark brown; conidia obclavate to subcylindrical, straight, 58 to 147 × 5 to 6 μm, 6 to 16 septate, hila thickened and darkened with a thin-walled projecting papilla, dark brown, and verrucose. The morphology of the Brazilian collections agrees well with the description of Stigmina palmivora (2), a species known to cause leaf spots on P. roebelenii in the United States (Florida) and Japan (3). Pathogenicity was demonstrated through inoculation of leaves of healthy plants by placing 6 mm diameter cuture disks of COAD1338 on the leaf surface followed by incubation in a moist chamber for 48 h and then transferred to a greenhouse bench at 21 ± 3°C. Typical leaf spots were observed 15 days after inoculation. DNA was extracted from the isolate growing in pure culture and ITS and LSU sequences were generated and deposited in GenBank under the accession numbers KF656785 and KF656786, respectively. These were compared by BLASTn with other entries in GenBank, and the closest match for each region were Mycosphaerella colombiensis strain X215 and M. irregulariamosa strain CPC 1362 (EU514231, GU2114441) with 93% of nucleotide homology (over 100% query coverage) for ITS and 98% of nucleotide homology (over 100% query coverage) for LSU. There are no sequences for S. palmivora deposited in public databases for comparison, but for Stigmina platani, the type species in this genus, 86% and 96% nucleotide homology for ITS and LSU with S. palmivora were found. The genus Stigmina is regarded as being polyphyletic (1) and this is probably reflected by these low homology levels found in the BLASTn search. To our knowledge, this is the first report of Stigmina palmivora in Brazil. References: (1) P. W. Crous et al. Stud. Mycol. 75:37, 2012. (2) M. B. Ellis. Dematiaceous Hyphomycetes. Commonwealth Mycological Institute, Kew, UK, 1971. (3) D. F. Farr and A. Y. Rossman. Fungal Databases. Syst. Mycol. Microbiol. Lab. ARS, USDA. Retrieved from http://nt.ars-grin.gov/fungaldatabases/ , 2013. (4) H. Lorenzi et al. Palmeira no Brasil: Exóticas e Nativas, 2nd ed. Editora Plantarum, Nova Odessa, Brazil, 2005.

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