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Search for "KREJZOVÁ R.": 15 articles found.
KREJZOVÁ R. (1988): Seasonal dynamics of the formation and discharge of Entomophthora conidia in vitro. Česká Mykologie 42(2): 105-113 (published: 10th May, 1988)
abstract
The formation and discharge of conidia during the whole vegetation season was observed in cultures of two isolates of Conidiobolus thromboides Drechsler and one isolate of Entomophthora destruens Batko et Weiser. Individual species and often even isolates markedly differ from one another in the number of discharged conidia and in the general course of conidiation. The optimum period for conidiation was from the beginning of the season till the end of September.
KREJZOVÁ R. (1988): The formation and discharge of conidia in cultures of entomophthorus fungi. Česká Mykologie 42(1): 31-40 (published: 10th February, 1988)
abstract
The formation and discharge of conidia from twenty isolates of five species of entomophthorous fungi (Conidiobolus thromboides, Entomophthora destruens, Entomophthora pyriformis, Erynia neoaphidis and Zoophthora radicans) were studied with regard to their cultivation period in vitro. With the exception of E. pyriformis, isolates with both markedly high and very low numbers of discharged conidia occurred in all species. The capacity of conidium production and discharge was not very significantly dependent upon the in vitro cultivation period of the isolate. The course of conidium formation was characteristic for individual species and often markedly differed from the others.
KREJZOVÁ R. (1987): Pathogenicity of Erynia neoaphidis for Acyrthosiphon pisum. Česká Mykologie 41(2): 65-72 (published: 8th May, 1987)
abstract
The mycological material from an epizootic on Acyrthosiphon pisum Harris on alfalfa was evaluated. Pathogenicity of two isolates of Erynia neoaphidis Remaudière et Hennebert 1980 was tested and compared with the pathogenicity of the same fungus applied via infected aphids. The death rate of infected aphids was primarily influenced by relative humidity, regardless of whether the fungal material came from culture or from dead infected hosts.
KREJZOVÁ R. (1981): Surface structure of the fungus Zoophthora radicans. Česká Mykologie 35(2): 57-63 (published: 15th May, 1981)
abstract
The most distinctive characteristics of the fungus Zoophthora radicans shown in SEM micrographs are the ridges and grooves on the typical cup-like papilla of conidia, the spoon-like form of the thread-like conidiophore with anemoconidium, and finely wrinkled surface of anemoconidia. No attaching device of anemoconidia was found. The fungus was obtained from Dr. I. Hall’s laboratory, Department of Biological Control, University of California, in 1966. It was primarily isolated by Hall and Dunn (1957) from Therioaphis maculata (Buckton) and described as Entomophthora exitialis Hall et Dunn. This name was considered nomen confusum by Remaudière and Hennebert. In a revision, the authors placed the fungus definitely to Zoophthora radicans (Brefeld) Batko. The culture of the strain Z. radicans, which we obtained, grew in our collection for years on Sabouraud glucose agar or on coagulated egg yolk medium only as hyphae. In our previous experiments we managed to induce mycosis in Galleria mellonella L. larvae by an injection of suspension from cut hyphae and to obtain not only hyphal bodies, but also reproductive stages in the form of conidia. In order to complete the morphological studies of the fungus we have examined some developmental stages under the scanning electron microscope.
KREJZOVÁ R. (1977): Morphology and surface structure of Conidiobolus coronatus (Cost.) Batko II. Formation and germination of conidia. Česká Mykologie 31(3): 139-141 (published: 1977)
abstract
Conidia of Conidiobolus coronatus and their germ tubes and hyphal bodies were studied by scanning electron microscopy. This fungus was found to form these stages in a large number and wide variety, which enables it to adapt itself to the conditions of the environment. Conidiobolus coronatus is able not only to parasitize man, mammals, insects and plants, but it grows also as a saprophyte. The discharged conidia are at first highly turgid and with smooth surface. Later their surface becomes slightly undulate. The membranes of older conidia are regularly pitted or furrowed, only the papilla with its circular facets remains relatively smooth. Also the surface of germ tubes and hyphae becomes gradually furrowed due to drying and shift of protoplasm.
KREJZOVÁ R. (1977): Morphology and surface of Conidiobolus coronatus (Cost.) Batko. Česká Mykologie 31(1): 28-30 (published: 1977)
abstract
The fungus Conidiobolus coronatus was studied by means of a scanning electron microscope. Besides conidia germinating to microconidiophores, and conidia with mature microconidia, also intermediate stages were observed in the micrographs. The conidia with microconidiophores were thus the initial stages of microconidia-producing conidia and not resting spores. The resting spores with typical three-layer envelope were not observed.
KREJZOVÁ R. (1976): Record of Entomophthora (Triplosporium) fresenii (Nowakowski) Gustafsson in Czechoslovakia and its taxonimic evaluation. Česká Mykologie 30(3-4): 207-213 (published: 1976)
abstract
Entomophthora fresenii was found for the first time in Czechoslovakia on Aphis fabae. A new taxonomic status is proposed: Entomophthora subgen. Triplosporium stat. nov. based on morphological evidence and literature review.
KREJZOVÁ R. (1976): Ultrastructure of conidia of Paecilomyces fumoso-roseus (Wize) Brown et Smith isolated from Zoothermopsis sp. Česká Mykologie 30(2): 110-114 (published: 1976)
abstract
Keratinolytic fungi in bird nests are influenced by nest moisture. Species richness and isolation frequency of Chaetomium decline with higher humidity. Literature on moisture tolerance in fungi is reviewed, emphasizing ecological and physiological aspects.
KREJZOVÁ R. (1975): Morphology and taxonomy of the species Conidiobolus coronatus (Constantin) Srinivasan et Thirumalachar (1964). Česká Mykologie 29(3): 174-178 (published: 1975)
abstract
Conidiobolus coronatus was isolated as an airborne contaminant in a newly built house in Prague. This species is known both as a saprophyte and a pathogen of insects and mammals, including humans. The isolate was studied morphologically and cultured on various media. Its significance for hygiene is discussed.
KREJZOVÁ R. (1974): List of species and strains of the genus Entomophthora cultivated in the collection of theInstitute of Entomology, Czechoslovak Academy of Sciences, Prague. Česká Mykologie 28(3): 189-190 (published: 1974)
KREJZOVÁ R. (1973): The resistance of cultures and dried resting spores of three species of the genus Entomophthora to ajatin and the viability of their resting spores after long-term storage in the refrigerator. Česká Mykologie 27(2): 107-111 (published: 1973)
abstract
Light with an intensity of 1000 to 5000 lux inhibits the release of zoospores and the formation of zoosporangia of hop downy mildew (Peronoplasmopara humuli Miy. et Tak.). Zoosporangia release zoospores in water suspension both in light and darkness already after one hour. With increasing light intensity, however, the percentage of zoosporangia releasing zoospores decreases: after 6 hours 95% release zoospores in darkness and 72–84% in light. Light affects more sharply the onset of zoosporangia formation and the density of the mildew coating. In darkness the first zoosporangia form after 4 hours and a continuous dense coating after 12 hours. In light, depending on intensity, the first individual fruiting bodies and zoosporangia form after 6–22 hours, and their number remains nearly unchanged even after 30 hours of exposure. The inhibitory effect of light is only temporary, as the pathogen resumes forming dense, infective zoosporangia after 10–20 hours back in darkness under optimal conditions.
KREJZOVÁ R. (1971): Resistance and germinability of resting spores of some species of the Entomophthora. Česká Mykologie 25(4): 231-238 (published: 1971)
abstract
Resting spores of Entomophthora thaxteriana germinated after 5 years in cold storage; spores of E. virulenta and E. destruens germinated after 2 years. Spores resisted high temperatures (up to 100°C) for limited times and still retained viability. They remained viable after 18 months at –30°C.
KREJZOVÁ R. (1971): Submerse Kultivation der insektenpathogenen Pilzarten Entomophthora traxteriana (Petch) Hall et Bell und Entomophthora destruens Weiser et Batko. Česká Mykologie 25(2): 118-124 (published: 1971)
abstract
The fungi Entomophthora thaxteriana (Petch) Hall et Bell and Entomophthora destruens Weiser et Batko were cultivated in amino acid-rich liquid media. Yield of vegetative mass and resting spores was measured under varying pH and compared with E. virulenta. Morphological and physiological growth patterns of these Entomophthora species in submerged culture are described. Historical taxonomy and previous misidentifications of E. thaxteriana are discussed.
KREJZOVÁ R. (1970): Submerged cultivation of Entomophthora virulenta Hall et Dunn 1957. Česká Mykologie 24(2): 87-94 (published: 20th April, 1970)
abstract
The nutrient solutions most suitable for submerged cultivation of Entomophthora virulenta Hall et Dunn 1957 were tested for maximum vegetative growth and resting spore formation. The study evaluates historical and modern media used for isolation and cultivation, highlighting industrial needs and physiological research applications.
KREJZOVÁ R., WEISER J. (1968): Stigmatomyces limnophorae Thaxter 1901 (Ascomycetes, Laboulbeniales), a new fungus for Cuba with remarks to its morphology. Česká Mykologie 22(3): 220-224 (published: 1968)
abstract
A Cuban strain of Stigmatomyces limnophorae Thaxter was studied on Limnophora arcuata. Its morphology closely resembles S. sarcophagae, later synonymized with S. limnophorae. Ascospores, ascus structure, and multiple stalks with radicoids from successive generations are described.
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