The ectomycorrhizal biodiversity of selected Norway spruce stands on an Alpine limestone mountain was studied by inventories of occurring fruitbodies and descriptions of new ectomycorrhizal types. Based on fruitbody surveys a total of 137 ectomycorrhizal and 48 saprophytic species was recorded. Dependent on elevations as well as microclimatic, soil, and stand conditions there were significant differences in the fungal composition and number of species between the investigated forest plots.

Preliminary results and methodology related to the use of the fluorescence in situ hybridization technique for detection of plants hybrids are presented. Total genomic DNA probe preparation and the non-isotopic biotin probe labelling technique is presented. The use of an excess of unlabelled competitor DNA from a related plant species gives more constant results in determining whole plant genomes with in situ experiments on plant hybrids. Preliminary results of flourescence in situ hybridization for detecting alien rye chromatin and localisation on metaphase chromosomes and interphase nuclei in the bread wheat cultivar Yugoslavia are described. The methodology for detection of interspecies hybrids of common and sessile oak with flourescence in situ hybridization is given. The advantege of the use of total genomic biotin labelled probes for in situ hybridization is that it requires less effort than preparing species specific probes and the ease of interpretation of the results. The technique of fluorescence in situ hybridization is less species than other cytological techniques for higher plants and almost the same methodology can be used for detection of oak hybrids. The extraction of a high quantity of species specific DNA of high quality and probe preparation and labelling are the most important step.

The effect of atmospheric NH3 deposition on freezing tolerance of needles of Scots pine was investigated. Needles from 3 month old seedlings and from 20-30 year old field-grown Scots pine (Pinus sylvestris L.) trees were studied. Seedlings were exposed to NH3 during the first stage of hardening in the laboratory. Field-grown trees were growing in a "clean" or an NH3 polluted area. In the 3 month old seedlings, exposure to 1000 ml 1** (-1) NH3 for 4 weeks resulted in a 40 increase of total nitrogen content. Freezing tolerance of the needles was significantly enhanced in the NH3 exposed seedlings. In the field-grown trees, current and one year old needles were studied. Freezing tolerance of the current year needles did not differ significantly between the two forest stands. However, one year old needles from the NH3 polluted stand were significantly less frost hardened from October until February. Total nitrogen content was higher in both current and one year old needles from the NH3 polluted stand. At the same time, potassium content of these needles was lower compared to the needles from the clean stand. The content of calcium, magnesium and phosphorus did not differ significantly. It was concluded that a decrease of freezing tolerance upon atmospheric NH3 was not directly related to an increased nitrogen content, but might probably be due to the nutrient imbalance of the needles.

Biotrophic fungal interaction with host plants involve alterations in host metabolism in favour of the fungus, characteristic of perturbations in the levels of plant growth regulators. Pyrenopeziza brassicae mycelia, culture filtrate and spore extracts contained zeatin riboside and iso-pentenyladenisine-type cytokinins as determined using HPLC-ELISA. The significance of cytokinin synthesis by P. brassicae in relation to infection of host plant tissue is discussed.

Types of ectomycorrhizae on Norway spruce were determined in soil cores from two differently polluted forest research plots from the emission zone of Sostanj Thermal Power Plant (TPP). The two plots are comparable regarding site characteristics, but are differently polluted by the emmissions from the TPP. During the vegetations season 1993, 21 soil cores were taken from each plot. In these all fine roots and ectomycorrhizal roots tips were counted and the percentages of different types were calculated. Additionally, soil mycorrhizae from underneath fungal fruit bodies were taken in order to characterize new types of ectomycorrhizae. Classical anatomical methods and molecular tools were applied for identification. 17 types of ectomycorrhizae were determined on 28443 root tips in soil cores from the heavily polluted plot (Zavodnje). The predominant types were Paxillus involutus, Xerocomus badius, Piceirhiza parallela and Piceirhiza inflata. On the less polluted plot (Mislinja) 24 different types were determined on 38502 root tips in equal volume and number of soils cores. The most frequent types were Hydnum rufescens, Amphinema byssoides, Piceirhiza oleiferans, Cenococcum geophilum and Lactarius lignyotus. Mycobioindication of forest site pollution through selective sensitive (here Hydnum rufescens), in comparison to unsensitive (here Paxillus involutus), fungal species in ectomycorrhizae is discussed.

Distribution patterns of ectomycorrhizal types and length density of finest roots were investigated in three comparable Scots pine ecosystems located along a deposition gradient of air pollutants in the new states of Germany. The plots Rosa, located near Bitterfeld and Halle, had received high depositions loads of SO2, NOX and alkaline fly ashes due to chemical industries and brown coal fired power plants in the former German Democratic Republic. Taura, located near Leipzig, was moderately affected by air pollutants. The background site Neuglobsow is located in a remonte area north of Berlin. All the three plots were dominated by only a few mycorrhizal types. Mycorrhizal projection area of these types was highest in Neuglobsow and strongly reduced at the polluted plots. The distribution patterns of mycorrhizal types differed also qualitatively. Length density of finest roots was lower in the humus layer of Neuglobsow than in the humus layer of Rosa and Taura. The results are correlated to high nutrient inputs and high rates of N-mineralization at the impacted plots.

The paper summarizes the main results of reach on heavy metal detoxification in ectomycorrhizas of Rhizopogon roseolus, Paxillus involutus, Cenococcum geophilum and Pisolithus arrhizus formed on Pinus sylvestris roots collected from heavily polluted areas in Poland. The data were obtained by methods including electron microscopy (TEM, SEM) accompanied by EELS and EDAX, cytochemical stainings and capillary electrophoresis. All of the species described in the paper are fungi highly resistant to toxic elements. As detoxification in mycorrhizas is dependent on both partners, the phenomenon was studied in fungi and in Pinus sylvestris roots. The strongest element-filtering effect was observed in R. roseolus / P. sylvestris symbiosis. This mycorrhiza type was characterized by the accumulation of heavy metals in the fungal mantle, and a gradual decrease of these elements was observed along the Hartig net towards the inside of the root. Potentially toxic elements were localized intercellularly in crystals deposited on the mantle and hyphal surface and in pigmented layer of the cell wall of the extramatrical hyphae, and the hyphae of the outer mantle layer. They were also detected intracellularly within electron-opaque depositions in the vacuoles. Much lower levels of toxic elements were detected in plant cells. The most common place for heavy metal accumulation was the phenolic material of the cortical cells.

First studies of this kind were based on mapping of cover and frequency of crustose, foliose and fructicose epiphytic lichens on trees which were assessed also for the decline symptoms. Since 1985 epiphytic lichen vegetation has been assessed by this methods and results, expressed as a lichen map of Slovenia were used as an air quality indicator for plots of forest die-back inventory. In case studies of forest decline, in collaboration with lichenologist from Graz Univ., Austria, all epiphytic lichen species were mapped in order to obtain better measure of air quality in the area studied. Very polluted and still clean and well preserved forests were investigated. From the material collected and determined a lichen herbarium has been established on the Slovenian Forestry Inst.. Possibilites of further research and use of epiphytic lichens as air quality indicators are discussed.

The condition of silver fir (Abies alba Mill.) trees was monitored 1988-1994 by measuring electrical resistance of living tissues at breast height. Slime cells in bark and traumatic resin canals in wood were investigated as possible symptoms of silver-fir decline.