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

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 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

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

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

In Zherong county, Fujian province, the black spot of Pseudostellaria heterophylla often breaks out in the rainy season from April to June every year. As one of the main leaf diseases of P. heterophylla, black spot seriously affects the yield and quality of the medicinal material. To identify and characterize the pathogens causing black spot, we isolated the pathogens, identified them as a species of Alternaria according to Koch's postulates, and then tested their pathogenicity and biological characteristics. The results showed that the pathogens causing P. heterophylla black spot were A. gaisen, as evidenced by the similar colony morphology, spore characteristics, sporulation phenotype, and the same clade with A. gaisen on the phylogenetic tree(the maximum likelihood support rate of 100% and the Bayesian posterior probability of 1.00) built based on the tandem sequences of ITS, tef1, gapdh, endoPG, Alta1, OPA10-2, and KOG1077. The optimum conditions for mycelial growth of the pathogen were 25 ℃, pH 5-8, and 24 h dark culture. The lethal conditions for mycelia and spores were both treatment at 50 ℃ for 10 min. We reported for the first time the A. gaisen-caused black spot of P. heterophylla. The results could provide a theoretical basis for the diagnosis and control of P. heterophylla leaf spot diseases.
Bayes Theorem ; Phylogeny ; Caryophyllaceae ; Alternaria ; Mycelium

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

In July 2002, a destructive stem rot of tawny daylily(Hemerocallis fulva) was occurred sporadically in exhibition farm of Gyeongsangnam-do Agricultural Research and Extension Services located in Hamyang-gun, Korea. The fungus also caused collar and crown rot, and systemic wilt or blight of whole plant. White mycelium spread over stems and petioles of infected plants and sclerotia were formed on the old lesions and near the soil surface. The optimum temperature for mycelial growth and scierotial formations was 30degrees C on PDA. The mycelial width ranged 4.2~10.4microm and the color was white, usually many narrow mycelial strand grew in the aerial mycelium and formed clamp connection. The shape of sclerotia was spherical and 1.0~3.2 mm in diameter. The fungus was isolated repeatedly from the infected tissues and confirmed its pathogenicity to Hemerocallis fulva and identified as Sclerotium rolfsii. This is the first report on the stem rot of H. fulva caused by S. rolfsii in Korea.
Crowns ; Fungi ; Gyeongsangnam-do ; Hemerocallis* ; Korea* ; Mycelium ; Plants ; Soil ; Virulence