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Ključne besede: varstvo gozdov, morfološke analize
Objavljeno v DiRROS: 05.09.2025; Ogledov: 241; Prenosov: 0
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Povzetek: Background Xylophilus ampelinus is a plant pathogenic bacterium that causes bacterial blight in grapevines, which can lead to severe yield losses and economic damage. Owing to its fastidious growth on culture media, detection is primarily based on molecular methods. However, existing tests have produced inconsistent results, particularly when used to detect latent infections and non-validated matrices. There is a risk of false-positive results, with economic consequences such as restrictions on international trade. To enhance the diagnostics of X. ampelinus, a genome-informed approach was utilised to identify new potential targets for specific detection. On the basis of these sequences, multiple real-time PCR assays were designed, and their specificity and sensitivity were assessed, as well as their performance validated across three different grapevine tissues, including leaves, roots, and xylem. Results The newly designed real-time PCR assays were evaluated via high throughput testing for specificity and sensitivity and compared with a reference assay. The most promising assays were selected and validated in different grapevine tissues and included in a test performance study to validate their reproducibility and robustness. Three new assays (Xamp_BA_2, TXmp22.4, and Xamp_BA_7) demonstrated high specificity and sensitivity for X. ampelinus detection. The Xamp_BA_2 assay exhibited the best overall performance, offering high diagnostic sensitivity and robustness across diverse plant matrices. Importantly, the assays exhibited no cross-reactivity with non-target bacterial species and maintained high detection accuracy across diverse grapevine tissue types. Conclusions The newly developed real-time PCR assays provide an enhanced diagnostic framework for the detection of X. ampelinus in various plant matrices, significantly improving the applicability of molecular testing. The Xamp_BA_2 assay demonstrates superior performance and is recommended for routine diagnostics, with other validated assays being employed for confirmation of identification. The development of these new assays represents a significant expansion of our toolkit for the precise detection of X. ampelinus in grapevines, with the potential to contribute to the mitigation of grapevine bacterial blight, the prevention of yield losses, and the protection of international trade in grapevine material. Further implementation of these assays will support regulatory and phytosanitary efforts to mitigate the spread of X. ampelinus.
Ključne besede: Xylophilus ampelinus, grapevine bacterial blight, molecular diagnostics, Vitis vinifera, real-time PCR, genome-informed assay development
Objavljeno v DiRROS: 05.09.2025; Ogledov: 388; Prenosov: 170
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Povzetek: The National Institute for Environmental Studies (NIES) developed the NIES CRM No. 13-a, a new certified reference material for human hair, using scalp hair from Asian females. This CRM represents a significant advancement in support of global mercury exposure assessments and offers unparalleled reliability and scope compared with existing materials. We aimed to provide a comprehensive overview of the preparation, certification, and application of NIES CRM No. 13-a. In total, 806 bottles (3 g each) were produced, with thorough homogenization ensured through sieving and blending. Certified values for total mercury (1.06 ± 0.07 mg/kg), methylmercury (0.858 ± 0.075 mg/kg), and key trace elements (arsenic, cadmium, lead, selenium, and zinc) were determined through extensive collaborative analyses involving 20 laboratories. Additional reference values were provided for calcium, magnesium, sodium, sulfur, antimony, barium, copper, iron, and manganese. Rigorous stability and homogeneity assessments demonstrated the stability of the CRM for over 10 years and consistency across sample units, even for challenging elements such as selenium. The CRM also includes information values of stable mercury isotope ratios, reflecting their growing importance as exposure tracers. This enhancement in accuracy and traceability facilitates accurate mercury and trace element assessments in human hair, enabling improved biomonitoring of mercury exposure, dietary studies, toxicological evaluations, human health risk evaluations, and regulatory compliance.
Ključne besede: metilirano živo srebro, methylmercury, certified reference material
Objavljeno v DiRROS: 05.09.2025; Ogledov: 292; Prenosov: 115
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Povzetek: Pseudomonas syringae (Psy) is a widely distributed bacterial species complex primarily recognized as a foliar pathogen but also inhabits diverse environments, including water habitats, where strains closely related to agricultural pathogens have been identified. The connection between Psy-caused epidemics and its potential presence in nearby irrigation systems remains underexplored. This study comprehensively examined the Psy complex in the Danube-Tisa-Danube Hydrosystem (DTD) in Serbia, assessing its abundance, phylogenetic diversity, and pathogenic potential. To reduce the reliance on the time-consuming steps of isolation and identification, we developed novel high-specific primers and probes for precise detection of strains belonging to phylogroup 2 within Psy complex. Our results demonstrated that dPCR, coupled with highly specific and sensitive primers, outperformed both traditional plating and qPCR in detecting the Psy complex and phylogroup 2 in irrigation waters, making Psy diagnostics more effective. Phylogenetic analysis indicated high strain diversity within the DTD, identifying phylogroups 1, 2, 7, 12, and 13 and haplotypes linked to strains previously encountered in epidemics on sugar beet in Serbia. Notably, 66.67% of the isolates from the DTD were capable of inducing disease. Phylogroup 2 isolates displayed a broad host range, suggesting that the dissemination of Psy from DTD through irrigation, poses a substantial threat to crop health and agricultural productivity.
Ključne besede: phytopathogen detection, irrigation, qPCR, dPCR
Objavljeno v DiRROS: 05.09.2025; Ogledov: 301; Prenosov: 123
Celotno besedilo (6,95 MB)
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Ključne besede: varstvo gozdov, morfološke analize
Objavljeno v DiRROS: 05.09.2025; Ogledov: 164; Prenosov: 0
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