Root-induced changes in the rhizosphere and root colonization with mycorrhizal fungi have marked influence on mineral nutrient acquisition from soils. Enhanced exudation of organic acids under phosphorus deficiency is a widespread phenomena in woody species forming root clusters. Root colonization with endomycorrhizas (AM) and ectomycorrhizas (ECM) increases the spatial availability of nutrients in the soil and enhances plant growth particulary on nutrient-poor soils. Most of these studies have been conducted under controlled environmental conditions and with annual plant species mycorrhizal with AM. Conclusions on the role of ECM colonization for nutrient acquisition of trees in forest stands are not possible at the present state of knowledge.

We have been isolating AC/GT and AG/CT SSRs from the Norway spruce (Picea abies K.) nuclear genome. We isolated several hundreds positive clones from a small-insert genomic library and following sequence analysis we designed primers for 36 of them, 24 containing AG and 12 AC SSRs. After testing them on a panel of spruce individuals 25 of the primer pairs producted a single-locus hypervariable pattern, with the remaining ones giving either a single monomorphic product (18) or very poor amplification (19) or amplification of multiple bands (38). Segregation in accordance with a simple Mendelian model of inheritance was demonstrated for all the loci amplified with the primer pairs giving a simple variable pattern. We screened a panel of 19 spruce trees at these loci. The average number of alleles per locus was 14 and expected heterozygosity 0.80, with up to 23 alleles per locus and heterozygosities exceeding 0.94. This shows that nuclear SSRs can be very useful markers in the population genetics of trees even though the overall efficiency of the marker identification process is quite low due to the high percentage of primer pairs producting complex or "dirty" patterns. We attribute this phenomenon to the high complexity of the spruce genome. Other methods, including the construction of libraries highly enriched for SSR sequences, that we developed in order to make SSR retrival and typing easier and faster will be discussed. We recently extended the use of PCR amplified SSR markers to the chloroplast genome. We demonstrated that mononucleotide poly(A/T) stretches are frequent in the chloroplast genomes of plants and show high levels of between and within population variation, making them ideal tools for cytoplasmic population genetic overcoming the difficulties in finding within species variation that are frequently encountered when analysing the cpDNA molecule by RFLPs or PCR-RFLPs. We will present results of the analysis of mediterranean pine species populations by using a set of cpSSRs that are distributed over the whole cpDNA molecule and discuss the possible applications of such markers for studying gene flow and for paternity analysis.

The haploid chromosome set of Norway spruce consists of 12 chromosomes. Most of the chromosomes are very similar in their morphology (length, arm ratio, secondary constriction). For the CGBI it is necessery to recognize all chromosomes. Therefore we used different banding methods to solve this problem. We used the root meristem and the dividing cells of the macrogametophyte as test objects. We discussed morphology of chromosomes of these two different dividing tissues. The use of image analysis equipment made it possible to get in a relatively short time a great number of data for statistical analysis. Another method was, to use an expert-system for data analysis. Finally 3-D models of interphase nuclei were reconstructed.

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.

Forest soil was sampled on two different observation plots by following well described methodology. Sampling sites had been chosen in place with typical soil conditions for the observed forest site. To make sampling easier some natural forest site characteristics were considered. Mg, Zn and Cd were determined by atomic absorption spectroscopy in all samples. Results were statistically evaluated and different sources of variance were estimated. It was also estimated whether the number of samples was sufficient for our requirement for accuracy of analytical results.

This article deals with use of several bioindication methods in forest decline studies within an international TEMPUS project carried out in Slovenia. The aim of the project was to introduce and connect different bioindication methods in order to improve methods and qualify the research staff working in this research field in Slovenia. The following bioindication methods were introduced or adapted for forest decline research in Slovenia: biochemical and physiological markers of air pollution / stress impact on forest trees (Graz Univ.: photosynthetic pigments, thiols, ascorbic acid, protective enzyme systems; Cambridge Univ.: plant hormones; Munich Univ.: mineral nutrition of forest trees); epiphytic lichens as indicators of air quality on forest sites (Graz Univ., Ljubljana Univ); determination of types of ectomycorrhizae as indicators of forest soil condition (Munich Univ., Ljubljana Univ.). The significance and practical use of bioindication methods in environmental studies is also discussed.

Tissue specific localization of soluble secondary metabolites was demonstrated in ectomycorrhizae and uninfected roots of Picea abies, Larix decidua, Pinus sylvestris and Abies alba. Compounds were analysed by HPLC and by histochemical methods. Specific distribution and age-dependent changes were observed with several metabolites. For catechin corresponding patterns were found within the cortex of all investigated conifers. Levels of this metabolite were highest within the apical cortex cells and decreased on aging of the tissue. In spruce contents of catechin showed evident seasonal changes. Stilbene glucosides were detected within the pericycle of spruce roots and as well the phloem tissue of larch with levels increasing during root development. In larch two anthocyanins accumulated in the calyptra. In older tissues of larch roots larixin-glucosid and quercetin-rhamnosid were detected, the latter with highest levels in the phloem tissue. For cell wall bound ferulic acid increasing levels could be found concomitant with the development of the root.

To use alterations to epicuticular wax morphology as a successful tool in forest damage research, however, it is necessary to distinguish environmental influence and artefacts from common pollution effects. This paper gives a short review about alterations to epicuticular wax morphology of spruce needles.

The Forest Research Plot was chosen on a typical site for the Pokljuka plateau. It is covered by a supposedly autochthonous old Norway spruce stand with rejuvenation centres. Data on the physiological parameters can be used as representation values for a subalpine Norway spruce stand. The studies include: standard site and dendrological parameters, physiological parameters (foliar analysis, antioxidants, hormones and aminoacids in spruce needs), genetical and biochemical analysis (isoenzymes and molecular markers), microbiological activity (acid phosphatase, rate of decomposition, number and occurrence of fungal decomposers of wood and litter) and studies of symbionts and pathogens of Norway spruce (mapping of fruitbodies of mycorrhizal fungi, types of ectomycorrhizae, endophytes, epiphytes - lichens and phytopathological surveys). All physiological and ecological studies are planned to be repeated at certain time periods in order to understand better the functioning of the forest ecosystems on Pokljuka.

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.