20.500.12556/RUL-190604 Verticillium albo-atrum partitivirus 1 Is a highly prevalent and stably maintained cryptic virus of hop-associated Verticillium nonalfalfae The soilborne plant-pathogenic fungus Verticillium nonalfalfae causes Verticillium wilt in hop. Infections caused by its highly virulent (lethal) pathotype can lead to the development of a severe level of disease that poses a major threat to hop production. In this study, we investigated the occurrence of mycoviruses in V. nonalfalfae isolates representing different geographical regions and virulence groups using double-stranded RNA isolation and high-throughput sequencing. Notably, Verticillium albo-atrum partitivirus 1 (VaaPV1) was detected in 46 of 90 isolates (51.1%), including both lethal and mild pathotypes. Thirty isolates were sequenced, revealing low genetic divergence, with nucleotide identities of 93.9%–100% for RdRp and 94.5%–100% for CP. The low dN/dS ratio of the RdRp gene (0.119) further indicated strong purifying selection. VaaPV1 was efficiently maintained during fungal growth: hyphal tipping failed to eliminate the virus from any of 70 regenerated cultures, while only 13 of 73 cultures regenerated from protoplasts were virus-free. Furthermore, VaaPV1 was transmitted horizontally through hyphal anastomosis from all tested donor isolates. Comparisons between infected and isogenic virus-free isolates revealed no significant differences in fungal growth or virulence on hop, indicating that VaaPV1 establishes a cryptic infection without detectable phenotypic effects under the conditions tested. Overall, our findings demonstrate that VaaPV1 is highly prevalent, genetically conserved and stably maintained in hop-associated V. nonalfalfae, providing a baseline for future studies of the ecological and biological significance of mycovirus infections in this vascular wilt pathogen. hop mycovirus VaaPV1 Verticillium wilt hmelj mikovirusi verticilijska uvelost true false true Angleški jezik Slovenski jezik Članek v reviji 2026-10-30 10:55:54 2026-10-30 10:56:01 2026-10-31 04:34:10 0000-00-00 00:00:00 2026 0 0 12 str. Iss. 5, art. e70298 Vol. 75 2026 0000-00-00 Zaloznikova Objavljeno NiDoloceno 0000-00-00 0000-00-00 0000-00-00 578 0032-0862 https://bsppjournals.onlinelibrary.wiley.com/doi/10.1111/ppa.70298 10.1111/ppa.70298 303217411 Plant_Pathology_-_2026_-_Miljanic_-_Verticillium_alboatrum_partitivirus_1_Is_a_Highly_Prevalent_and_Stably_Maintained.pdf Plant_Pathology_-_2026_-_Miljanic_-_Verticillium_alboatrum_partitivirus_1_Is_a_Highly_Prevalent_and_Stably_Maintained.pdf 1 739C05D87294C9110AB7548699BD3848 282962e334ef8c8a69f9b99230467cb9193ad0e6dade2a24b93b2f596abf1394 a2a2615b-d448-11f1-aea2-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=252133 https://bsppjournals.onlinelibrary.wiley.com/doi/10.1111/ppa.70298 0 f1d88c6a-d448-11f1-aea2-0050569b8976 https://repozitorij.uni-lj.si/Dokument.php?lang=slv&id=252135 Biotehniška fakulteta 0 0 0