Contributions towards the consistent ID of powdery mildew (Erysiphales, Ascomycota) species

Abstract

• Powdery mildews (Erysiphales, Ascomycota) are an order of plant pathogenic fungi that infect 10,000 different angiosperm species, including important crop species. Traditional morphological methods of identifying powdery mildews can be difficult and time consuming, as different character states can be hard to distinguish. Molecular techniques using the ITS region fail to provide a species level identification 1 out of every 4 times and often must be used in conjunction with morphology to provide an identification beyond genus. The Mcm7 gene could potentially be used to provide more accurate identifications and build phylogenies incorporating large number of taxa to help understand the systematics of the order. Here, it is found that incorporating Mcm7 and ITS into a phylogeny greatly increases bootstrap support values, suggesting that Mcm7 may be used in the future to understand the systematics of this previously problematic order. ITS is successfully extracted from more and older specimens than Mcm7 and recommendations on using Mcm7 in the lab are made.