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1.
We report a javelina from Pinal County, Arizona, USA, with severe fungal dermatitis and cellulitis. Extreme emaciation and rostral disfiguration, including left-lateral displacement of the nasal planum, justified euthanasia. A pus-filled tract within the rostrum was observed. Histopathology revealed granulomatous inflammation with hyphae morphologically consistent with Alternaria sp. isolated by culture. 相似文献
2.
Alternaria rot of Pingguoli pear occurred after latent infection. Fruit surfaces were asymptomatic within 60 days storage under cold condition (0°C, RH 85–90%), but black‐grey hyphae could be seen in the lenticels or calyx tube of Pingguoli pear after 90 days of storage. The tissue collapsed and resulted in visible black spots as the hyphae spread over the fruit. Average incidence of Alternaria rot of fruits from an orchard in Gansu was 28.86% at 100 days of storage. The main fungus isolated from the Alternaria rot on stored Pingguoli pear was identified as Alternaria alternata (Fr. : Fr.) Keissl. This pathogen was able to initially infect the fruit via two pathways during the growing season, and then remain in a latent state. The fungus first colonized the styles at the full‐blossoming stage, and then grew into the carpel cavities progressively after 50 days from petal fall. The percentage latent infection of A. alternata was up to 45% in the carpel cavity until the harvest time. The fungus also attacked fruit surfaces and remained latent in the fruit peel during fruit development. The percentage of A. alternata latent infection at the calyx end, middle part and stem end of the fruit peel was 40%, 24% and 42.8%, respectively, at harvest time. 相似文献
3.
A serious wilt disease of guava has been observed in the Varanasi district of eastern Uttar Pradesh of India. The causal organism has been identified as Fusarium oxysporum f. sp. psidii. Pathogenicity tests were performed in pot experiments to confirm the causal agent of the disease. Infected plants developed chlorosis followed by wilting of entire seedlings and leaf abscission. Histopathological studies showed the presence of hyphae in xylem vessels of roots of the wilted seedlings and when sections of such roots were transferred to potato dextrose agar medium, this pathogen grew in culture. 相似文献
4.
New fossil remains have been discovered from the well-known Lakhanda Microbiota (1015–1025 Ma, Uchur-Maya Region, Southeastern
Siberia). The microfossils have characters observed in microscopic fungi, such as a reticulate mycelium, formed by anastomizing
hyphae of non-cellular structure and of variable width. The fungal mycelium shows that hyphae grew in a certain direction,
both forwards and backwards. As their length increased, the hyphae became curved and merged with neighboring hyphae to form
enclosed spaces. The presence on hyphae of knoblike trapping structures and secretion of adhesive enzymes suggest a similarity
with modern nematophagous fungi. Microorganisms associated with the adhesive hyphae consist of colonial green unicellular
algae and thin bacterial sheaths, which may indicate mutually beneficial relationships between morphologically and biologically
different partners. Microfossils of fungal origin are systematically described. They include Aimonema ramosa gen. et sp. nov. and the green unicellular alga Eoprotoderma neruenica gen. et sp. nov., forming a symbiotic association. 相似文献
5.
Darko Vucicevic Janis E. Blair Matthew J. Binnicker Ann E. McCullough Shimon Kusne Holenarasipur R. Vikram James M. Parish Nancy L. Wengenack 《Mycopathologia》2010,170(5):345-351
Coccidioidomycosis, the fungal infection caused by dimorphic Coccidioides sp., is typically diagnosed by histopathologic identification of spherules in affected secretions and tissues or by culture.
These tests are reliable but time-intensive, delaying diagnosis and treatment. To evaluate a polymerase chain reaction (PCR)
test developed to detect Coccidioides sp. in clinical specimens, we conducted a retrospective chart review of all patients (N = 145) who underwent Coccidioides PCR at our institution between April 27, 2007, and May 6, 2008, abstracting clinical, microbiologic, serologic, radiographic,
treatment, and follow-up data. One hundred fifty-eight PCR tests (153 respiratory; 5 cerebrospinal fluid) produced 5 positive
and 153 negative findings. Five of nine patients (56%) with confirmed or highly probable pulmonary coccidioidomycosis had
a positive PCR on respiratory specimens, and four of nine (44%) had a positive culture. Among two patients with coccidioidal
meningitis, none had a positive PCR, whereas Coccidioides sp. in fungal culture grew for one of two. Among six asymptomatic patients with probable coccidioidomycosis, none had a positive
culture or PCR. Compared with culture of respiratory specimens, PCR demonstrated a sensitivity, specificity, positive predictive
value, and negative predictive value of 75, 99, 60, and 99%, respectively. Coccidioides PCR appears accurate in identifying negative results, and its sensitivity is similar to that of fungal culture. 相似文献
6.
Fusarium oxysporum f. sp. radicis-lycopersici can Induce Systemic Resistance in Barley Against Powdery Mildew 总被引:1,自引:0,他引:1
H. E. Nelson 《Journal of Phytopathology》2005,153(6):366-370
Drench inoculation of the undisturbed roots of barley seedlings with Fusarium oxysporum f. sp. radicis‐lycopersici (FORL) significantly reduced the primary infection frequency of Blumeria graminis f. sp. hordei (BGH) on the first leaves. The length of secondary hyphae and subsequent conidial production of BGH were also found to be significantly reduced by preinoculation with FORL. The reduction in infection frequency was observed as early as 48 h after inducer treatment, namely when plants were challenge‐inoculated immediately following inoculation with FORL. The induced resistance continued up to 16 days after treatment as indicated by the reduction in infection frequency, up to 22 days after treatment when evaluated as a reduction in the length of secondary hyphae, and up to 35 days after treatment when evaluated as a reduction in conidial production. Characteristics of FORL that may explain its success as an inducer of resistance against barley powdery mildew are discussed. 相似文献
7.
C. Natarajan R. Prasanna V. Gupta P. Dureja L. Nain 《Applied Biochemistry and Microbiology》2012,48(1):51-57
An investigation was directed towards biochemical characterization of cyanobacterium Calothrix elenkinii and analysis of the chemical nature and mode of action of its fungicidal metabolite(s) against oomycete Pythium debaryanum. Biochemical characterization of the culture in terms of carbohydrate utilization revealed the facultative nature of C. elenkinii. Unique antibiotic markers were also found for this strain. 16S rDNA sequencing of the strain revealed 98% similarity with
Calothrix sp. PCC7101. The fungicidal activity was tested by disc diffusion assay of different fractions of the culture filtrate. A
minimum inhibitory concentration of 10 μl was recorded for ethyl acetate fraction of the 7-weeks old culture filtrates. HPLC,
followed by NMR spectral analysis demonstrated the presence of a substituted benzoic acid in the ethyl acetate fraction. Microscopic
examination revealed distinct granulation, followed by disintegration of the hyphae of Pythium sp., indicating the presence of an active metabolite in the culture filtrates of Calothrix sp. The fungicidal activity of C. elenkinii can be attributed to the presence of 3-acetyl-2-hydroxy-6-methoxy-4-methyl benzoic acid. This is the first report of a benzoic
acid derivative having fungicidal activity in cyanobacteria. 相似文献
8.
Mycoparasitism by Coniothyrium minitans on Sclerotinia sclerotiorum and its Effect on Sclerotial Germination 总被引:1,自引:0,他引:1
J. C. Tu 《Journal of Phytopathology》1984,109(3):261-268
Scanning electron microscopy showed that hyphae of Coniothyrium minitans produced appressorium-like swellings when they came in contact with Sclerotinia sclerotiorum in dual culture on PDA. The parasitized hyphae gradually skrank and collapsed, and hyphae of the mycoparasite were found inside the host hyphae. The mycoparasite hyphae grew inter- and intracellularly within the sclerotia of S. sclerotiorum. In the later stages of parasitism, hyphae of the mycoparasite proliferated extensively within the sclerotia and formed pycnidia near the sclerotial surface. At this stage, the sclerotia became flattened, soft and disintegrated. Sclerotia parasitized by C. minitans failed to germinate either myceliogenically or carpogenically. 相似文献
9.
从野生艾蒿的根茎叶部位分离出内生细菌共68株,以棉花枯萎病、稻瘟病、烟草赤星为供试病原菌,采用对峙法对内生菌分别进行抑菌试验,对筛选出的菌株进行了16S rDNA序列测定和系统发育分析。结果表明:从野生艾蒿分离到的内生菌经初筛、复筛,获得抑制病原菌效果最明显的3株菌,结合生理生化特性、菌落特征、细胞形态特征和16S rDNA测序分析结果,菌株L8、S11和R6分别鉴定为Bacillus subtilis,Bacillus cereus,Paenibacillus polymyxa。拮抗实验表明,棉花枯萎病原菌菌丝发生弯曲、打结,烟草赤星的受作用菌丝生长端分枝明显增多,生长端边缘呈珊瑚状分枝,并且出现明显的畸形和萎缩现象。分析表明,可能是由于在培养过程中内生菌产生了化感物质,对病原菌的菌丝产生抑制作用的结果。 相似文献
10.
Studies were conducted on microfungi isolated from soils in the Windmill Islands, continental Antarctica. Growth responses
of Alternaria alternata, Chrysosporium pannorum, Nectria peziza, Thelebolus microsporus, Mycelia sterile and Phoma cf. herbarum to temperature, pH and culture media were investigated. Maximum growth occurred after 16 days, except in Nectria peziza and Thelebolus microsporus, where maximum growth occurred 12 days after inoculation. All isolates showed poor growth at 0°C. Maximum growth was obtained
with temperatures ranging from 15 to 25°C. The optimum temperature for all fungi was 20°C. An acid medium favoured growth.
Chrysosporium pannorum, Phoma cf. herbarum and Nectria peziza grew best at pH 3–4, whereas Mycelia sterile, Alternaria alternata and Thelebolus microsporus grew best at pH 5–6. The culture medium had little effect on growth, except for nutrient agar, which showed poor growth against
all isolates with the exception of Thelebolus microsporus.
Received: 11 September 1996 / Accepted: 13 January 1997 相似文献
11.
J. C. Tu 《Journal of Phytopathology》1988,121(2):97-102
Streptomyces griseus produces an antibiotic substance against Colletotrichum lindemuthianum because, in dual culture on potato dextrose agar (PDA), a large inhibitory zone was formed between the colonies of S. griseus and C.lindemuthianum. When S. griseus was placed adjacent to a colony of C. lindemuthianum in PDA, S.griseus grew poorly in PDA but it thrived and sporulated profusely when it came in contact with a colony of C. lindemuthianum indicating that S.griseus might require some essential nutrients from C.lindemuthianum. Scanning electron microscopy showed that hyphae of S.griseus in contact with C.lindemuthianum produced appressorium-like swellings or simply grew on the hyphal surface of C.lindemuthianum. Internal parasitism was evidenced by the presence of hyphae and conidia of the mycoparasite inside the host hyphae. Internal parasitism resulted in formation of several blebs. Cell walls of the parasitized hyphae degenerated having a sponge-like texture. The blebs broke off and left rounded holes on the hyphae. 相似文献
12.
Biodegradation of polyethylene glycol by symbiotic mixed culture (obligate mutualism) 总被引:5,自引:0,他引:5
Neither Flavobacterium sp. nor Pseudomonas sp. grew on a polyethylene glycol (PEG) 6000 medium containing the culture filtrate of their mixed culture on PEG 6000. The two bacteria did not grow with a dialysis culture on a PEG 6000 medium. Flavobacterium sp. grew well on a dialysis culture containing a tetraethylene glycol medium supplemented with a small amount of PEG 6000 as an inducer, while poor growth of Pseudomonas sp. was observed. Three enzymes involved in the metabolism of PEG, PEG dehydrogenase, PEG-aldehyde dehydrogenase and PEG-carboxylate dehydrogenase (ether-cleaving) were present in the cells of Flavobacterium sp. The first two enzymes were not found in the cells of Pseudomonas sp. PEG 6000 was degraded neither by intact cells of Flavobacterium sp. nor by those of Pseudomonas sp., but it was degraded by their mixture. Glyoxylate, a metabolite liberated by the ether-cleaving enzyme, inhibited the growth of the mixed culture. The ether-cleaving enzyme was remarkably inhibited by glyoxylate. Glyoxylate was metabolized faster by Pseudomonas sp. than by Flavobacterium sp., and seemed to be a key material for the symbiosis. 相似文献
13.
Fifty fungal types were isolated from the indoor atmosphere of saw mills by exposing Petri plates containing Czapek-dox Agar, Potato-dextrose Agar and Sabouraud Agar media for 5 min. The fungal flora of the outdoor surroundings was also studied for comparison. Species ofAspergilli dominated in the saw mills, being represented by 16 species including one ascosporic form. Other fungi were species ofCladosporium, Alternaria, Curvularia, Penicillium, Fusarium, etc. Variations in the fungal population in different months were also observed. Fungal spores recovered using the Rotorod Sampler wereAlternaria, Curvalaria lunata, Curvularia tetramera, Cladosporium, Dreschslera sp.,Epicoccum sp.,Pithomyes sp.,Nigrospora, Stemphylium sp. andTorula sp. Mycelial fragments and unidentifiable spores were also seen in abundance. Varying allergic responses of patients were also recorded by testing intradermally, the antigens of nineAspergilli, vizAspergillus flavus, A. fumigatus, A. japonicus, A. melleus, A. nidulans, A. niger, A. niveus, A. tammarii and A. terreus. 相似文献
14.
Fifty fungal types were isolated from the indoor atmosphere of saw mills by exposing Petri plates containing Czapek-dox Agar,
Potato-dextrose Agar and Sabouraud Agar media for 5 min. The fungal flora of the outdoor surroundings was also studied for
comparison. Species ofAspergilli dominated in the saw mills, being represented by 16 species including one ascosporic form. Other fungi were species ofCladosporium, Alternaria, Curvularia, Penicillium, Fusarium, etc. Variations in the fungal population in different months were also observed. Fungal spores recovered using the Rotorod
Sampler wereAlternaria, Curvalaria lunata, Curvularia tetramera, Cladosporium, Dreschslera sp.,Epicoccum sp.,Pithomyes sp.,Nigrospora, Stemphylium sp. andTorula sp. Mycelial fragments and unidentifiable spores were also seen in abundance. Varying allergic responses of patients were
also recorded by testing intradermally, the antigens of nineAspergilli, vizAspergillus flavus, A. fumigatus, A. japonicus, A. melleus, A. nidulans, A. niger, A. niveus, A. tammarii and A. terreus. 相似文献
15.
Dani Eshel Delila Beno-Moualem Jennifer M. Lorang Amos Dinoor Dov Prusky 《Journal of Phytopathology》2002,150(6):357-362
Limited black spot symptoms (Quiescent infections) develop on persimmon fruits as Alternaria alternata hyphae penetrate the pericarp of green‐immature fruit. Inoculation of persimmon with A. alternata or treatment with a commercial preparation of purified cellulase induced similar black symptoms and higher peroxidase activity in green‐immature fruits but not in orange‐mature persimmon fruits. Both treatments induced the development of new peroxidase isoforms only in immature fruits – however, no effect was observed on polyphenoloxidase activity. A. alternata was transformed with a construct expressing green fluorescent protein (GFP). Histological analysis of hyphal development using GFP‐transformed fungi indicated that symptoms are always found ahead of the leading edge of the hyphae. We suggest that peroxidase increase, induced by the directly penetrating A. alternata, might be involved in the induction of quiescence infection by the pathogen in immature fruits. 相似文献
16.
Ten strains of fungi were tested for tolerance to the fungicide benomyl. Verticillium chlamydosporium strain 2 did not grow in the presence of benomyl; Drechraeria coniospora strains 1 and 2 and Chaetomium sp. tolerated only 0.1 μg benomyl/ml medium; Acremonium bacillisporum, an unidentified fungus, and Phoma chrysanthemicola uniformly grew at 1 μg/ml, but some hyphae grew at higher benomyl concentrations; Fusarium sp. tolerated 475 μg/ml, but some hyphae grew on medium amended with 1,000 μg/ml; Verticillium lecanii and V. chlamydosporium strain 1 routinely tolerated 1,000 μg/ml. Fungi generally grew more slowly at higher than at lower benomyl concentrations. Strains with elevated tolerance to benomyl were selected from Acremonium bacillisporum, Drechmeria coniospora, Fusarium sp., and an unidentified fungus. These strains retained the increased tolerance after repeated transfers on unamended medium. 相似文献
17.
Erika Di Marino Linda Scattolin Philomena Bodensteiner Reinhard Agerer 《Mycological Progress》2008,7(3):169-176
The ectomycorrhizal status of Sistotrema sp. is shown by morphological–anatomical and molecular identification, confirming earlier reports about Sistotrema DNA in ectomycorrhizae (ECM). For molecular identification of the ECM nuclear rDNA ITS sequences obtained from mycorrhizal
root tips and fruitbodies of Sistotrema sp. were compared. Blast searches using the Sistotrema sp. sequences as query were performed in GenBank and UNITE for comparison with previously published Sistotrema sequences. The morphological–anatomical characterization of the ECM used well-established protocols for the examination of
all mantle parts and rhizomorphs in different sections and views including detailed illustrations. The ECM are irregularly
monopodial–pyramidal, whitish ochre to yellow ochre, and woolly. Older ones become more greyish and silvery at some patches.
Diagnostic anatomical characteristics are irregularly inflated emanating and rhizomorph hyphae, ampullately inflated clamps,
and the occurrence of yellow drops within the hyphae. The plectenchymatous mantle shows ring-like arranged hyphae, and a slightly
gelatinous matrix. The ECM of Sistotrema sp. are compared to those of other species that form distinctly ampullate hyphae in rhizomorphs, too. The anatomically most
similar ECM to those of this Sistotrema specimen are those of Hydnum repandum. 相似文献
18.
Following trauma with rice stalk to the left eye, corneal ulcer with abscess and hypopyon developed in an immunocompetent
male. Direct examination of the corneal scrapings revealed septate, branched fungal hyphae. Bipolaris hawaiiensis was isolated after culture on blood agar and Sabouraud dextrose agar. Because of delay in diagnosis and appropriate treatment,
the patient developed endophthalmitis needing evisceration. 相似文献
19.
We report for the first time the establishment of an arbuscular mycorrhizal association between Glomus sinuosum (= Sclerocystis sinuosa) and transformed Ri T-DNA carrot (Daucus carota L.) roots in monoxenic culture. The G. sinuosum sporocarps survived not as single spores, but as sporocarps in the environment. The mode of germination of G. sinuosum was by extension of hyphae around the sporocarp. Numerous vegetative spores, arbuscules and vesicles were produced after the roots were infected by the hyphae. New mature sporocarps started to form after four months in the culture system. Forty-seven sporocarps were produced on average in each culture dish after six months, and these newly produced sporocarps were capable of germination in the growth medium. 相似文献
20.
SPF white mice were inoculated intraperitoneally with 5 strains of saprophytic fungi of the mycelial genera Chrysosporium (C. keratinophilum, C. tropicutn) and Paecilomyces (P. lilacinus, P. marquandii, P. victoriae). The fungi caused granulomatous lesions in the peritoneal cavity and they were recultured (except P. lilacinus and P. marquandii) two months after inoculation. Spores, short hyphae and budding cells of all the fungi were observed in the granulomas stained by periodic-acid Schiff (PAS) and methenamine-silver nitrate (Grocott) techniques. 相似文献