Visualisation of ectomycorrhizal rhizomorph structure using laser scanning confocal microscopy

A method for the observation of the three-dimensional structure of intact ectomycorrhizal rhizomorphs is described. The method is based on a combination of clearing the material with KOH followed by staining with congo red and subsequent imaging under a laser scanning confocal microscope (LSCM). The images obtained are of a much higher three-dimensional resolution than those obtained previously by use of conventional light microscopical techniques. The structure of highly differentiated and undifferentiated rhizomorphs is described. Applications of the method are briefly discussed

Challenges for mycorrhizal research into the new millennium

Some future directions for mycorrhizal research are discussed. Data from The IPCC Third Assessment Reports 2001 on elevated carbon dioxide the concentration and consequences regarding global climate change, form the basis for arguments that a better understanding of the mycorrhizal activities with regard to controlling carbon flow and plant nutrient flow is essential. Mycorrhiza can be regarded as energy and nutrient switches in the plant roots and it is suggested that more studies on mycorrhizal carbon relations are necessary. The impact of the genomic research era on mycorrhizal research is suggested to be of major importance during the years to come, and it is claimed that stronger interactions between different disciplines will be essential

Vertical distribution of microfungi in a spruce forest soil in south of Sweden

Soil-washing technique was used for the isolation of microfungi from soil of a planted Norway spruce forest in the south of Sweden. About ninety different fungal species were identified. The most frequently isolated genera were Mortierella, Penicillium, and Trickoderma which together constituted 71% of the total number of isolates. A significant (P < 0·01) difference in abundance between the different soil horizons was found for twenty-three species. The results are discussed in relation to earlier mycological studies in coniferous forest soils

Some problems in assessing the fluorescein diacetate-active fungal biomass in the soil

Abstract A technique for assessing the metabolically-active fungal biomass by means of fluorescein diacetate (FDA) staining was recently described (Söderström, 1977). In this note some practical details in the application of this technique to studies of FDA-active fungal biomass in the soil are discussed

Vital staining of fungi in pure cultures and in soil with fluorescein diacetate

A method for vital staining of fungal mycelium with fluorescein diacetate (FDA) is described. In experiments with pure cultures, good correlation was obtained between relative staining efficiency, growth rate, and respiration. FDA thus appears to be a true vital stain, in that it stains only metabolically active mycelia. In fresh soil suspensions stained with FDA, brightly fluorescent hyphae and portions of hyphae were observed. The applicability of the method for measurement of active mycelium in the soil is discussed

The Ecological Potential of the ectomycorrhizal Mycelium

Abstract is not availabl

Seasonal fluctuations of active fungal biomass in horizons of a podzolized pine-forest soil in central Sweden

Metabolically-active fungal biomass determined by fluorescein diacetate (FDA) staining, was studied during a 27-month period in three horizons of a podzolized pine-forest soil. Recurrent biomass peaks were registered in autumn and early spring. Biomass increase was also noted during the winter with soil temperatures below 0 deg C. Only a minor fraction (2.4-4.3%) of the total fungal biomass was active. The FDA-active biomass was equally distributed between the organic (5 cm) and mineral (15 cm) soil horizons, and varied between 0.5 and 2.4 g d.w. m-2. The amount of FDA-active biomass was correlated with soil moisture content

Ectomycorrhiza - ecology of the fungal partner

Abstract is not availabl

Mycorrhizal mycelia and their role in soil and plant communities

Interactions between mycorrhizas and soil microbial and faunal populations, including those between different mycorrhizal populations are discussed along with the nutritional and non-nutritional interactions between fungi and plant roots and their influence on the structure, development and functioning of plant communities. The discussions relate principally to vesicular-arbuscular and ecto-mycorrhizal fungi, although ericoid mycorrhizal associations are also briefly considered