Morphological and molecular characterization of Podosphaera lini on Linum usitatissimum in IRAN

Linum usitatissimum, known as flax, is grown all around the world. Powdery mildew is a common disease on this crop so that this disease has been described from most flax-growing areas of the world. Clear symptoms of powdery mildew were observed on the field of different flax cultivars of Seed and Plant Improvement Institute of Iran in 2020 growing season. The causal pathogen of flax powdery mildew was identified as Podosphaera lini based on the morphological features and the nuclear ribosomal DNA internal transcribed spacer sequence. This is the first documented report of P. lini from flax in Iran.