First report of powdery mildew caused by Leveillula taurica on Opsicarpium insignis

Species of fungi in the order Erysiphales cause disease referred to as powdery mildew which affect more than 10,000 angiosperm species (Glawe, 2008). These are obligate pathogens with a global distribution especially temperate regions northern hemisphere (Braun & Cook, 2012). Iran possesses one richest apiaceous floras world (Valiejo-Roman et al., 2006) and some these susceptible mildew, including Opsicarpium insignis. This is perennial, endemic plant that grows 150 cm high. A fungus on leaves insignis was collected October 2013, June 2018 2020, Zagros Mountain, Oshtorankouh, western (voucher specimen GUM 1735 deposited fungarium University Guilan). Disease symptoms appeared irregular white/grey patches upper lower leaf surfaces, usually extended whole (Figures 1-3). Microscopic examination showed primary conidia were lanceolate, half narrowing towards apex, measured 14–18 × 42–54 μm, length/width ratio 2.9-3, widest or sometimes middle conidia. Secondary cylindrical, sub cylindrical somewhat clavate, approximately long (12-24 37–54 μm). Chasmothecia scattered gregarious, (146-246 μm diameter). Appendages well developed, arose from chasmothecia branched infrequently. Asci numerous, about 22–27 per chasmocarp, elongate-ovoid 20–38 75–92 μm. stalked two-spored. Ascospores ovoid ellipsoid, (12-18 μm) (Figure 4). Morphological characteristics similar Leveillula taurica, described by Braun Cook (2012). To confirm morphological identification, total DNA extracted mycelia using Chelex method (Hirata Takamatsu, 1996). The ITS1/ITS4 primer pair used amplify ITS region (Cunnington 2003) nucleotide sequences resulting amplicons obtained direct sequencing. sequence edited MEGA 7 (Edgar, 2004; Kumar 2016) GenBank (Accession No. KT221623). Sequences compared those BLASTN confirmed identification L. taurica >99% identity Capsicum annuum USA (GQ167201), Coronilla varia Lotus corniculata Iran. Nineteen selected for phylogenetic analyses based their identity, along three Phylactinina guttata, four Podosphaera pannosa two Sawadaea tulasnei accessions outgroups. aligned MUSCLE 2004) tree neighbour-joining (Kumar results 5). our knowledge this first record globally. authors would like thank Valliollah Mozafarian aid species.