Archivio Journal of Plant Pathology

Abstract:

Since 2009 leaf spot symptoms were observed on Lep idium draba whitetop an invasive weed collected in wheat plots Triticum sp in the Hamadan Province of Iran Typical symptoms included chlorosis of the basal leaves with black discrete ascomata protruding from the leaf surface Colonies of a fungus recovered from diseases leaves were brown to olivaceous with a white aerial mycelium in the center Since the morphological characters of this mycete were consistent with the description of Pleospora tarda Simmons 1985 its identification was confirmed by amplifying and sequencing the internal transcribed spacer region ITS of a representa tive isolate GenBank accession No KC660992 To fulfill Koch’s postulates a spore suspension 105 ascospores/ml of the fungus was sprayed onto leaves of whitetop seedlings at the 46 leaf stage Inoculated seedlings were maintained in a growth chamber at 25°C with more than 75% relative humidity and a 12 h light photoperiod Inoculated plants showed symptoms like those observed in the field 14 days post inoculation P tarda was reisolated from inoculated plants and a culture was deposited in the Iranian Research Institute of Plant Protection with the accession code IRAN 2184C To our knowledge this is the first report of P tarda infecting whitetop in Iran and in the world