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.

Three principal approaches are used in our laboratory to analyze plant genomes: (i) The construction of high density molecular maps: We have established a refined microdissection procedure to construct chromosomal and subchromosomal libraries. Synchronized meristematic root tip tissue from which metaphase spreads can be prepared with a novel dropspread technique in combination with nl-scale PCR allowed the cloning of DNA of 10 or less chromosomes or chromosome segments. The construction of high-resolution maps from discrete genome regions can greatly facilitate genetic fingerprinting, gene isolation and QTL studies. (ii) Synteny analysis: The Aegilops-based deletion mapping system in wheat with an array of deleted chromosome parts and chromosome-specific RFLP markers has lead to the construction of a high density physical consensus map of wheat. The integration of wheat, barley and oat RFLP markers proves the colinearity between the wheat A-, B- and D-genomes, the H- genome of barley and the E-genome of Agropyron. (iii) Gene mapping in situ and chromosomes at high resolution: For the sensitivity enhancement of fluorescence in situ hybridization (FISH), the efficient preparation of plant chromosomes for high resolution scanning electron microscopy, mapping of low-copy sequences, and for comparative in situ hybridization a modified drop technique for plant protoplasts was developed. A tandemly amplified repetitive sequence element from microdissected barley chromosomes has enabled the karyotyping of single Gramineae genomes in a single step. These sequences are also useful for simultaneous double or triple hybridization experiments in an attempt to localize new sequence on specific chromosomes or chromosome segments. The physical mapping of the Sec-1 locus has been refined on the satellite of chromosome 1R of rye, and the syntenic locus on barley chromosome 1H identified. A method was developed for in situ hybrization and signal detection at high resolution using a field emission scanning electron microscope and a backscattered electron detector. Colloidal gold particles were localized on chromosome structures resembling the 30 mm fibre. Comparatively, an rDNA probe was located in the secondary constriction and highly compact adjacent regions of barley chromosomes.

Mediterranean mussels, Mytilus galloprovincialis, are recognized bioindicators used in investigation of genotoxic pollution in the areas under the impact of anthropogenic activities. In July and August 2011 specimens of M. galloprovincialis were collected from 5 sites of Boka Kotorska Bay, Montenegro. Level of DNA damage was measured in gills, haemolymph and digestive gland with alkaline comet assay. Significant increase in DNA damage was detected in tissues of mussels collected from polluted sites comparing with mussels collected from the clean reference site Dobrota. The highest response to pollution was found in gills and digestive gland cells.