Emergence of Neopestalotiopsis rosae causing leaf spot and fruit rot on strawberry and assessment of cultivar response to infection

Abstract Strawberries ( Fragaria × ananassa ) are a vital fruit crop in Türkiye, ranking fifth globally in production. However, fungal diseases like leaf spot and fruit rot, recently associated with Neopestalotiopsis rosae , have emerged as significant threats. This study aimed to identify and characterize N. rosae using morphological and molecular tools and assess the resistance of Turkish strawberry genotypes. Field surveys conducted in 2019–2020 in Adana province collected symptomatic samples from 15 fields. Morphological examination on PDA revealed dense white mycelia with ellipsoidal, five-celled conidia bearing 2–3 apical appendages. Pathogenicity tests confirmed N. rosae as the causal agent, fulfilling Koch’s postulates. Disease severity, scored on a 0–3 scale, indicated that genotypes Sweet Charlie, Camarosa, Benicia, and Tüylü were highly susceptible, while Fortuna, Elsanta, and Eren 77 exhibited strong resistance. Twelve isolates were sequenced for the ITS region using ITS1/ITS4 primers and deposited in GenBank (PV065744-PV065761), showing 99–100% similarity with global N. rosae isolates from China, Serbia, Canada, and Peru. Phylogenetic analysis clustered Turkish isolates with international N. rosae strains and others. Fruit infection assays revealed that ‘Fortuna’ had the lowest lesion development, while ‘Sweet Charlie’ and ‘Camarosa’ showed the highest susceptibility. This study highlights the emerging threat of N. rosae in Türkiye and supports breeding efforts toward developing resistant strawberry varieties suited for Mediterranean climates.