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Poster: Diseases of Plants: New & Emerging Diseases


Powdery mildews on native plants in Utah
E. LAURITZEN (1) (1) Utah State University, U.S.A.

Many people want to grow more native plants in their yards. However, there is little information on plant diseases of native plants of the western United States. Powdery mildew is very common in Utah on many cultivated plants. The purpose of this project was to determine the presence of powdery mildew on native plants and identify the powdery mildew species using morphological and molecular techniques. Plants from the families Asteraceae, Geraniaceae and Polemoniaceae with powdery mildew were collected from a high elevation mountain valley (2,750 meters) in Northern Utah in fall 2015. Chasmothecia and conidia were collected from the plant tissue for morphological identification using a compound microscope. Identification to genuse and/or species was confirmed using polymerase chain reaction (PCR) amplifying the internal transcribed spacer (ITS) region and DNA sequencing. The resulting sequences were compared in a BLAST search to powdery mildew sequences in the NCBI GenBank database. Several species of powdery mildew including Podosphaera sp. on sticky purple geranium (Geranium viscosissimum) which to our knowledge is the first report of powdery mildew on this species in the United States and Golovinomyces magnicellulatus on Polemonium sp., the first report of this powdery mildew in Utah.