Antón-Domínguez, Begoña I.López-Moral, AnaLovera, MaríaArquero, OctavioTrapero, AntonioTrapero, CarlosAgustí-Brisach, Carlos2026-03-062026-03-062026Antón-Domínguez, Begoña I.; López-Moral, Ana; Lovera, María; Arquero, Octavio; Trapero, Antonio; Trapero, Carlos; Agustí-Brisach, Carlos (2026). Severity assessment of isolates of defoliating2239-7264http://hdl.handle.net/10198/35972Verticillium wilt, caused by the soilborne fungus Verticillium dahliae Kleb. is a major vascular disease affecting a wide range of woody and herbaceous hosts worldwide. The aim of this study was to assess the pathogenicity of defoliating (D) and nondefoliating (ND) V. dahliae pathotypes-isolated from pistachio (Pistacia vera L.) and olive (Olea europaea L.)-on two commonly used Pistacia rootstocks in the Mediterranean basin (P. terebinthus and UCBI hybrid) as well as on other major V. dahliae-susceptible hosts, such as olive, cotton (Gossypium hirsutum L.) and tomato (Solanum lycopersicum L.). Compared with the ND isolates, the D pathotype from olive induced greater disease progression in olive and cotton. However, no differences in the final disease severity in cotton were observed between D and ND isolates from olive. In terebinth plants, no significant difference in disease progression and severity was noted between the D and ND isolates, whereas UCBI remained symptomless and showed high resistance, although with a significant reduction in plant biomass in inoculated plants. Notably, the ND isolates from pistachio were significantly more aggressive on terebinth than on cotton or olive, highlighting host-specific interactions and the intraspecific variability of V. dahliae. These findings contribute to the understanding of V. dahliae host-pathogen dynamics and reinforce the importance of selecting resistant rootstocks, particularly in pistachio-growing regions where Verticillium wilt is prevalent in the soil.engGossypium hirsutumOlea europaeaPistacia sppSolanum lycopersicumUCBIVerticillium wiltjournal article10.1007/s42161-025-02092-w