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Povzetek: Phyllosticta citricarpa is the causal agent of citrus black spot (CBS), a disease affecting most citrus species and cultivars, particularly lemons (Citrus limon) and sweet oranges (C. sinensis). The pathogen causes fruit blemishes and premature fruit drop, leading to substantial yield and quality losses. Phyllosticta citricarpa is of global economic importance and is regulated by several citrus-growing countries, including those in the European Union (EU). The aim of this study was to develop a novel approach for early detection of P. citricarpa in environmental samples and to assess the status of P. citricarpa in selected citrus-growing areas of the EU where this species had previously been reported from leaf litter. Between 2018 and 2021, citrus plant material, air and rainwater samples were collected and analysed for the presence of Phyllosticta spp. in orchards in Greece, Italy, and Malta. Molecular analyses using qPCR assays targeting P. citricarpa were employed for the analysis of air and rainwater samples. The performance of the testing protocol was evaluated prior to sample analysis, and 1,000 conidia were determined to be the minimum number of spores required for reliable detection. No CBS symptoms were observed, and no evidence of P. citricarpa was found in collected citrus plant material, air, or rainwater samples. The only Phyllosticta species detected during this study was the endophyte P. capitalensis, isolated from citrus leaf litter in Greece. These findings support the results of official EU surveys, which indicate the current absence of P. citricarpa in the surveyed areas and demonstrate the value of integrating environmental monitoring with molecular diagnostics for plant health surveillance. The methodologies developed here offer a robust framework for early warning and rapid response, supporting efforts to prevent CBS outbreaks in Europe and can be adapted for other fungal pathogens.
Ključne besede: citrus black spot, early detection, molecular diagnostics, Phyllosticta citricarpa, spore trapping
Objavljeno v DiRROS: 30.03.2026; Ogledov: 283; Prenosov: 263
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Povzetek: In recent decades, the average crown defoliation of European beech (Fagus sylvatica) in Central Europe has been steadily increasing, resulting in a decline in tree vitality. This study aimed to identify the key factors contributing to this deterioration. Forty healthy and 40 damaged European beech trees were felled on a systematic 16 × 16 km grid, and all tree parts were sampled for fungi and insects. Additionally, soil samples were collected for Phytophthora testing. Of 6400 cultured samples, 5828 fungal cultures were classified into 251 morphotypes. The twenty most frequent morphotypes from each tree part were selected for further molecular identification, revealing 44 different fungal taxa. The most frequently isolated fungal species were Neonectria coccinea, Neohendersonia kickxii, Apiognomonia errabunda and Aureobasidium pullulans—all well-known and common endophytes. Surprisingly, Phytophthora species were detected in only three of the 80 soil samples. The most frequent insect species were Orchestes fagi, Phyllaphis fagi, Psilocorsis reflexella and Phyllonorycter maestingella. The results indicate that the decline of European beech in Central Europe is driven by a multifaceted interplay of biotic and abiotic factors, with fungi playing the most significant role. Analysis revealed distinct differences in fungal and insect communities across sampled tree parts, but not between healthy and damaged trees. This finding is crucial, as it shows that healthy trees host endophytes that can exhibit pathogenic traits under external stress factors. Therefore, resilience and sustainability of beech will depend on mitigation of stressors and implementation of adaptive management strategies that address the evolving environmental challenges.
Ključne besede: Fagus sylvatica, decline, complex disease, drought, climate change, sustainability
Objavljeno v DiRROS: 23.12.2025; Ogledov: 453; Prenosov: 278
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Ključne besede: plant diseases, Aculeastrum, urediniospores, spores, raspberry plant, genomic DNA, PCR
Objavljeno v DiRROS: 16.07.2025; Ogledov: 978; Prenosov: 523
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Povzetek: 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.
Ključne besede: biological control, postharvest disease management, antagonism, physiological variability, stress tolerance
Objavljeno v DiRROS: 04.03.2025; Ogledov: 1025; Prenosov: 574
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Ključne besede: leaf spots, Serbia, pathogen detection, common bean, phatoggenecity
Objavljeno v DiRROS: 23.10.2024; Ogledov: 1186; Prenosov: 381
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