Introduction. Sclerotium cepivorum is the causal agent of the disease commonly known as Allium root rot. It is a problem found all over the world on Allium spp. that can be very devastating since it can results in large crop losses. Once a field has S. cepivorum it is difficult and costly to continue growing Allium spp. there, if possible at all. The fungus is favored by cool weather and.
Stromatinia cepivora is a fungus in the division Ascomycota.It is the teleomorph of Sclerotium cepivorum, the cause of white rot in onions, garlic, and leeks. The infective sclerotia remain viable in the soil for many years and are stimulated to germinate by the presence of a susceptible crop.Pure culture sclerotia of Sclerotium cepivorum stimulated development of a number of bacteria on agar media. Using Bacillus subtilis and a chemically defined medium it was found that sclerotia could compensate for the absence of a carbon source but not of other constituents. The ethanol soluble carbohydrates of sclerotia grown on a number of carbon sources were identical to those produced on.Sclerotinia sclerotiorum is a plant pathogenic fungus and can cause a disease called white mold if conditions are conducive. S. sclerotiorum can also be known as cottony rot, watery soft rot, stem rot, drop, crown rot and blossom blight. A key characteristic of this pathogen is its ability to produce black resting structures known as sclerotia and white fuzzy growths of mycelium on the plant.
Abstract. Four fungal species were recorded in vitro as potential mycoparasites of sclerotia of Sclerotium cepivorum, the causal agent of onion white rot.Parasitised sclerotia appeared shrunken and decayed and failed to germinate. Light and scanning electron microscopy revealed colonisation of the internal structure of the sclerotium by the mycoparasites.
Data are presented on the antagonistic effects of the fungi isolated from sclerotia ofSclerotium cepivorum and from nonrhizosphere soil taken from around the roots of infected onions upon mycelial growth and sclerotial germination ofS. cepivorum. Most of the isolated fungi especiallyPenicillium species were antagonistic to mycelial growth.
Sclerotia of Sclerotium cepivorum were attacked by the mycoparasite more slowly than those of S. sclerotiorum. Sclerotia of Macrophomina phaseolina were not parasitized. The mycoparasite was isolated from soils from 3 different areas of the northeastern USA.
The response of sclerotia of Sclerotium cepivorum to a number of plant extracts and nutrient solutions was tested, aseptically, on agars, silica gels, filter paper discs, and on columns of soil.
Sclerotium, a persistent, vegetative, resting spore of certain fungi (e.g., Botrytis, Sclerotium). It consists of a hard, dense, compact mycelium (mass of filaments that make up the body of a typical fungus) that varies in form and has a dark-coloured covering. Size varies from a few cells to.
Vertical Distribution of Sclerotia of Sclerotium cepivorum and Host Root Systems Relative to White Rot of Onion and Garlic F. J. Crowe and D. H. Hall Formerly graduate research assistant, and extension plant pathologist, respectively, Department of Plant Pathology, University of California, Davis 95616.
The fungus, Sclerotium cepivorum Berk. is the causal agent of onion white rot disease and reproduces solely by means of sclerotia that persist in the soil between susceptible crops. Sclerotia are, th erefore, a vulnerable part of the lifecycle and disease control measures are being targeted towards them.
A survey to determine the presence of fungi with possible antagonistic effect against the sclerotia of Sclerotium cepivorum, causal agent of white rot of onion, was performed in the highlands of Cartago province, the main onion-production area in Costa Rica. Ten farms were studied from February to May 2002. Each farm was divided into 3 areas according to the historical incidence of the disease.
Sclerotia placed 30 cm deep in field beds germinated and infected garlic bulbs. Mycelium grew upward on roots and hyphae radiated 1-2 cm into soil, frequently infecting nearby roots. Leaves wilted and plants died only when the pathogen grew on to the stem plate and leaf sheaths. Masses of sclerotia formed as leaf sheaths decayed. Few sclerotia formed in roots.
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About the website The Author. Jeff Rollins is an Associate Professor of Plant Pathology at the University of Florida. I established this site to provide basic information concerning the pathogenic and developmental biology of Sclerotinia sclerotiurum and to share lab protocols. Information concerning mutant phenotypes and genomic-scale investigations will be posted in the near future.
Laboratory assays demonstrated that two isolates of Trichoderma viride and one isolate of Trichoderma pseudokoningii degraded up to 80% of sclerotia of four isolates of Sclerotium cepivorum in a silty clay soil, and also degraded up to 60% of sclerotia in three other soil types. Relationships were defined between the degree of sclerotial degradation by the two T. viride isolates in the silty.
Several species in Aspergillus section Nigri have been reported to produce sclerotia on well-known growth media, such as Czapek yeast autolysate (CYA) agar, with sclerotia considered to be an important prerequisite for sexual development. However Aspergillus niger sensu stricto has not been reported to produce sclerotia, and is thought to be a purely asexual organism.
Small, hard, irregular, black structures called sclerotia may be present on or in plant tissue (especially inside stem and petiole tissue). White fluffy growth on affected plant parts, this is most readily visible in high humidity. Spread: Sclerotia, long term survival structures, are found in soil and on plant debris.