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Abstract: Data collected in the project "Diseases, pests and drought stress of European beech at various climate change scenarios (V4-2026), Working package 2: Causes of the decline of European beech in Slovenia". Data was collected on 40 sampling plots, 39 plots on systematic grid 16 × 16 km and one additional plot in the Alps. On each sampling plot two trees were felled, altogether 80 trees: one visually healthy, and one damaged tree. Visual assessment of crown condition and damaging agents was evaluated following methods of ICP Forests. Rhizosphere soil was collected from each sampled tree for the Phytophthora baiting assay. For fungal isolations five parts of a tree were sampled: leaves, twigs (up to 20 mm in diameter), branches (over 20 mm in diameter), trunk, surface roots and root collar (up to 25 cm from the ground). Four samples from each tree part were collected. Finally, 20 samples per tree and 40 samples per plot were collected, yielding 1.600 samples in total. The samples were surface sterilized. Four subsamples were collected from one sample, altogether, 6.400 subsamples/tissue pieces. Four subsamples were plated on potato dextrose agar supplemented with streptomycin. Fungi and Phytophthora species were identified using molecular techniques, while insects were identified based on their morphological characteristics.
Keywords: research data, Fagus sylvatica, decline, damage, complex disease, fungi, insects, Phytophthora, endophytes, stress
Published in DiRROS: 25.09.2025; Views: 260; Downloads: 2
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Abstract: The "yeast-like" fungus, Aureobasidium pullulans, isolated from fruit and leaves exhibits strong biocontrol activity against postharvest decays on various fruit. Some strains were even developed into commercial products. We obtained 20 of these strains and investigated their characteristics related to biocontrol. Phylogenetic analyses based on internal transcribed spacer (ITS) and the D1/D2 domains of rRNA 28S gene regions confirmed that all the strains are most closely related to A. pullulans species. All strains grew at 0°C, which is very important to control decay at low storage temperature, and none grew at 37°C, which eliminates concern for human safety. Eighteen strains survived 2 hrs exposures to 50°C and two strains even survived for 24 hrs. Salt-tolerance varied; however, all strains grew on medium with 14% NaCl and 14 even with 18% NaCl. Such tolerances to high temperature and elevated salinity enable compatibility with postharvest practices. Substantial differences were observed in enzymatic activity, especially with respect to production of chitinases, xylanase, or urease. Siderophore production was detected and the ability to form biofilm varied widely between the strains. Knowledge of common characteristics of these strains may be very useful in future selection of the best antagonists within this species.
Keywords: biological control, postharvest disease management, antagonism, physiological variability, stress tolerance
Published in DiRROS: 04.03.2025; Views: 550; Downloads: 328
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Keywords: leaf spots, Serbia, pathogen detection, common bean, phatoggenecity
Published in DiRROS: 23.10.2024; Views: 738; Downloads: 241
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Abstract: The fungal genus Wallemia of the order Wallemiales (Wallemiomycotina, Basidiomycota) comprises the most xerotolerant, xerophilic and also halophilic species worldwide. Wallemia spp. are found in various osmotically challenged environments, such as dry, salted, or highly sugared foods, dry feed, hypersaline waters of solar salterns, salt crystals, indoor and outdoor air, and agriculture aerosols. Recently, eight species were recognized for the genus Wallemia, among which four are commonly associated with foods: W. sebi, W. mellicola, W. muriae and W. ichthyophaga. To date, only strains of W. sebi, W. mellicola and W. muriae have been reported to be related to human health problems, as either allergological conditions (e.g., farmer’s lung disease) or rare subcutaneous/cutaneous infections. Therefore, this allergological and infective potential, together with the toxins that the majority of Wallemia spp. produce even under saline conditions, defines these fungi as filamentous food-borne pathogenic fungi.
Keywords: food, air, pathogen, xerophile, halophile, mycotoxin, farmerʼs lung disease, subcutaneous infection
Published in DiRROS: 06.08.2024; Views: 762; Downloads: 749
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Abstract: Numerous agents of infections in humans and other mammals are found among fungi that are able to survive extreme environmental conditions and to quickly adapt to novel habitats. Nevertheless, the relationship between opportunistic potential and polyextremotolerance was not yet studied systematically in fungi. Here, the link between polyextremotol- erance and opportunistic pathogenicity is shown in a kingdom-wide phylogenetic analysis as a statistically significant co- occurrence of extremotolerance (e.g. osmotolerance and psychrotolerance) and opportunism at the level of fungal orders. In addition to extremotolerance, fungal opportunists share another characteristic%an apparent lack of specialised virulence traits. This is illustrated by a comparative genomic analysis of 20 dothideomycetous and eurotiomycetous black fungi. While the genomes of specialised fungal plant pathogens were significantly enriched in known virulence-associated genes that encode secreted proteases, carbohydrate active enzyme families, polyketide synthases, and non-ribosomal peptide synthetases, no such signatures were observed in human opportunists. Together the presented results have several implications. If infection of human hosts is a side effect of fungal stress tolerance and adaptability, the human body is most likely neither the preferred habitat of such species, nor important for their evolutionary success. This defines opportunism as opposed to pathogenicity, where infection is advantageous for the species% fitness. Since opportunists are generally incapable of the host-to-host transmission, any host-specific adaptations are likely to be lost with the resolution of the infection, explaining the observed lack of specialised virulence traits. In this scenario opportunistic infections should be seen as an evolutionary dead end and unlikely to lead to true pathogenicity.
Keywords: fungi, pathogenicity, infections in humans
Published in DiRROS: 24.07.2024; Views: 1041; Downloads: 3861
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