Selection of fungal strains with high virulence against the developmental stages of Bemisia tabaci was performed using internal transcribed spacer regions. The growth rate of hyphae was measured and bioassay of each developmental stage of B. tabaci was conducted for seven days. All of the fungal strains tested were identified as Lecanicillium spp., with strain 4078 showing the fastest mycelium growth rate (colony diameter, 16.3 +/- 0.9 mm) among the strains. Compared to strain 4075, which showed the slowest growth rate, the growth rate of strain 4078 was increased almost 2-fold after seven days. Strains 4078 and Btab01 were most virulent against the egg and larva stages, respectively. The virulence of fungal strains against the adult stage was high, except for strains 41185 and 3387. Based on the growth rate of mycelium and level of virulence, strains 4078 and Btab01 were selected as the best fungal strains for application to B. tabaci, regardless of developmental stage.
Adult ; Biological Assay ; Humans ; Hyphae ; Larva ; Mycelium ; Ovum ; Sprains and Strains

Development of oidia, a type of thallic spores from monokaryotic mycelium of Coprinus cinereus was examined with electron microscope and light microscopes. Oidia formation in this fungus is unique in its mode of formation compared with other types of asexual sporogenesis. Oidiogenesis in C. cinereus is carried out in three steps: 1) Formation of oidiophore from the parent mycelium, 2) Formation of initials of oidial cells from swollen oidiophore, 3) Segmentation and detachment of mature oidial cell. Oidiophores appear to spring out singly as a swollen hyphal branches from the normal foot hyphae or sometimes coiled hypha. From the oidiophore, oidial branches sprout out forming a group of 2~6, most often 4 oidial cells and each oidial cell undergoes a single mitosis resulting in 2 oidia. One of the sibling oidial cells in a group is frequently transformed into a new oidiophore, thus oidiogenic structures are tandemly produced at the several different levels.
Coprinus* ; Foot ; Fungi ; Humans ; Hyphae ; Mitosis ; Mycelium* ; Parents ; Siblings ; Spores

Twenty-three isolates of Fusarium spp. were obtained from decayed citrus fruits in the fields and storages in 1998-1999. Of them, six and five isolates belonged to F. proliferatum and F. moniliforme, respectively, which were the most common. F. solani and F. sambucinum had each two isolates, F. equiseti had one isolate and seven isolates were unidentified. They produced symptoms of two types in pathogenicity test: those with leathery, beige to light or dark brown, and sunken lesions without surface mycelium (type-1) and those with lesions covered with white, beige or pink surface mycelium (type-2). Four of six isolates identified to F. proliferatum and two unidentified isolates produced type-1 lesions, and all isolates identified to F. moniliforme, F. solani, F. sambucinum, F. equiseti and five unidentified isolates produced type-2 lesions.
Citrus* ; Fruit* ; Fusarium* ; Mycelium ; Virulence

A method of spawn making procedures through the application of fermented sawdust for the purpose of avoiding contamination by undesirable fungi in the course of Pleurotus ostreatus mycelial growth was evaluated. Of three kinds of supplements, rice bran was the most effective to raise temperature up to 70degrees C. Mycelial activity and density was more considerably improved in the case of using fermented sawdust supplemented with rice bran than the case of non-fermented sawdust. Primordia of Pleurotus ostreatus were formed on fermented sawdust. The substrate of fermented sawdust showed potential to prevent the growth of Trichoderma sp. which caused a symptom on mushroom mycelium, whereas there was nothing to inhibit the growth of Trichoderma sp. during 30 days after inoculation in non-fermented sawdust.
Agaricales ; Fungi ; Mycelium ; Pleurotus* ; Trichoderma

Nuclear distribution within the extra-radical fungal structures and during spore production in the arbuscular mycorrhizae fungus Glomus intraradices was examined using an in vitro monoxenic culture system. A di-compartmental monoxenic culture system was modified using a nitrocellulose membrane and a coverglass slip for detailed observations. Nuclear distribution was observed using the fluorescent DNA binding probes SYBR Green I and DAPI. Both septate and non-septate mycelial regions were observed, but cytoplasmic contents were only found within non-septate mycelia. Nuclear fluorescent staining revealed that the non-septate hyphal region contained nuclei only with cytoplasm, and that nuclear distribution was limited by septa. Swollen hyphal bodies were often associated with septate and empty-looking hyphae. Cytoplasmic contents filled the swollen hyphal body from the non-septate hyphal region following removal of the septa. As a consequence, the swollen body developed into a new spore. These observations provide understanding about the distribution of AM fungal nuclei within extra-radical mycelia and during spore formation. The results suggest a mechanism by which the development of a cytoplasm-containing mycelium is controlled by the formation or removal of septa to efficiently maintain and proliferate essential contents. This mechanism may provide a survival strategy to the fungus.
Collodion ; Cytoplasm ; DNA ; Fungal Structures ; Fungi ; Hyphae ; Indoles ; Membranes ; Mycelium ; Mycorrhizae ; Organic Chemicals ; Spores

BACKGROUND: The techniques that are currently used to diagnose nail infections, KOH and culture, can only provide indirect evidence of a fungal cause because false-negative and falsepositive results are high. The use of histologic examination can be of help for a more accurate and specific diagnosis. OBJECTIVE: This study was undertaken to investigate the characteristics of nail invasion and morphology in nail sections by 5 species of fungi including Trichophyton mentagrophutes var mentagrophytes, Trichophyton, rubrum, Candida albicans, Scopulariopsis brevicaulis, and Fusarium oxysporum. METHODS: Two in vitro methods for the study of nail invasion were used. In one method, those cultured fungi were inoculated on the ventral surface of the human nail clippings (direct nail inoculation method). In the other method, invasion of nail clippings by those fungi was induced in the continuous shaking liquid media (continuous shaking liquid culture method). RESULTS: 1. In direct nail inoculation method, the gross findings are similar to those obtained in routine culture media. By 1 week, the nail fragments were totally covered by a white fungal mycelium on gross examination. 2. Non-dermatophytes were slower invader of nail tissue than dermatohytes. Invasion was quicker and more extensive in the dystrophic nail. Full thickness invasion of the normal nail fragment was observed in 46.8+/-9.8 days. But it took 13.3+/-2.6 days to invade the dystrophic nail fragment (p<0.05). 3. This model showed the morphologic differences of three groups of fungi. Deramtolphytes gernerally showed regular, straight, septate and branched hyphae, which run parallel to the nail surface; C. albicans appeared as pseudofilaments running haphazardly within the nail; S. brevicaulis and F. oxysporum appeared as irregular, thicker hyphae without any spores. 4. By using the continuous shaking liqyid culture method, T. Mentagrophytes var mentagrophytes was only successful in nail invasion. CONCLUSION: The direct nail inoculation method is a simple method showing the dynamics of the nail invasion in vitro. Unlike to dermatolphytes, NDFF(non-dermatolphytic filamentous fungi) and Candida sp. could invade only dystrophic abnormal nail. Dermatophytes, Candida sp., and NDFF showed some differences in shape and arrangement fo the hyphae on the histopathologic sections. But they are not diagnostic to the species.
Arthrodermataceae ; Candida ; Candida albicans ; Culture Media ; Diagnosis ; Fungi* ; Fusarium ; Humans ; Hyphae ; Mycelium ; Nails, Malformed ; Running ; Scopulariopsis ; Spores ; Trichophyton

Four pathogenic fungal isolates belonging to different genera including Alternaria, Fusarium and Curvularia were isolated from selected diseased weeds growing in the fields in Dakahalia district. The inoculum of these pathogenic fungi specific to weeds were cultured, standardized and formulated as alginate pellets containing mycelium plus culture filtrate. These mycoherbicides were evaluated for disease severity (DS). Maximum DS was obtained with the alginate pellets of mycelium filtrate Fusarium solani. Physiological changes of the treated weed were determined 5 and 10 days after treatments. As compared to the healthy weeds, all mycoherbicide formulations significantly decreased the amount of photosynthetic pigments and subsequently soluble and insoluble sugars in the infected weeds. The mycoherbicide formulation of F. solani had the greatest effect on lowering to the abovementioned amount in the leaves of Chenopodium murale. Generally, treatment of weed leaves with the specific mycoherbicide led to a highly significant increase in total phenol content when compared to the healthy control weed. C. murale infected with the mycoherbicide formulation of F. solani had higher levels of phenolic compounds than those other treated weeds particularly after 10 days of inoculation.
Alternaria ; Carbohydrates ; Chenopodium ; Fungi ; Fusarium ; Mycelium ; Phenol

A destructive stem rot of wild aster (Aster koraiensis) occurred sporadically some farmers' fields in Guman-myon, Kosong-gun, Kyongsangnam-do in 2000. One of the most severely infected field in Kosong showed 28.6 percent of infection rate. The fungus also caused stem or crown rot and systemic wilt or blight of the plants. White mycelium spread over stems and petioles of infected plants and sclerotia formed on the old lesions and near the soil surface. The fungus showed maximum mycelial growth around 30degrees C and did not grow under 5degrees C and over 45degrees C and mycelial width were 4.3~10.2 microm. Colony was white, usually many narrow mycelial stand in the aerial mycelium and formed clamp connection. Numerous sclerotia were formed on PDA at 30degrees C. The shape sclerotia were globoid and 0.8~3.0x0.9~3.4 mm in size. The fungus was isolated repeatedly from the infected tissues and confirmed its pathogenecity to wild aster and identified as Sclerotium rolfsii. This is the first report on the stem rot of wild aster caused by S. rolfsii in Korea.
Crowns ; Fungi ; Gyeongsangnam-do ; Korea* ; Mycelium ; Soil

Perforated vinyl mulching technique was performed on oyster mushroom beds for controlling mushroom diseases. Mycelium under vinyl sheets were safely protected from outside undesirable microorganisms. One of two mushroom farms showed 75% of disease incidence, the other 40% and National Institute of Agricultural Science and Technology (NIAST) 13% in the conventional growing method, whereas 12%, 14%, and 5% in the vinyl mulching cultivation method. Waterlogging caused mushroom bed worse, and Trichoderma spp. were infested on the conventional mushroom bed. Disease incidence investigated in other case was 25% to 30% in the conventional growing method, whereas 5 to 9% in the vinyl mulching cultivation method. Yields in conventional method were 6.5 to 7.2 kg/m2 and those in vinyl mulching method were 7.6 to 8.1 kg/m2. So it was suggested that vinyl mulching technique was good for prevention from disease and elevation of productivity.
Agaricales* ; Efficiency ; Incidence ; Mycelium ; Pleurotus* ; Trichoderma

In Hezhang county, Guizhou province, black spot tends to occur to Aconitum carmichaelii in the hot rainy summer, with the incidence up to 50%-70%, seriously impacting the yield and quality of the medicinal material. Thus, this study aims to clarify the pathogen and the occurrence characteristics. To be specific, the pathogen was isolated and identified according to Koch's postulates and the pathogenicity and biological characteristics were determined. In addition, the sensitivity of the pathogen to four microbial fungicides, four botanical fungicides, and five chemical fungicides was determined with the mycelium growth rate method for the purpose of screening out optimal fungicides. The pathogen was identified as Alternaria alternate, as evidenced by the similar colony morphology and microscopic characteristics and 99.55%-100% similarity in sequences of rDNA-ITS, LSU, 18S, and TEF of the two. The optimum growth conditions for A. alternata were 28 ℃, pH 8, and continuous darkness. Bacillus subtilis had strong inhibitory effect on the pathogen, and the inhibition rate was more than 90% when the concentration was 1 mg·L~(-1). In addition, difenoconazole and quinoline copper can also control the pathogen, with median effective concentration(EC_(50)) of 2.92 and 9.02 mg·L~(-1), respectively. This study lays a theoretical basis for the field control of black spot in A. carmichaelii.
Aconitum ; Alternaria ; Fungicides, Industrial/pharmacology* ; Mycelium