Powdery mildew fungi (Erysiphales, Ascomycota) of Western Polissya of Ukraine

A critical revision of the powdery mildew fungi (Erysiphaceae, Ascomycota) of Ukraine: Arthrocladiella and Blumeria

The previously compiled list of species of powdery mildew fungi of Ukraine was published more than 30 years ago. That list included 108 species belonging to 12 genera. However, over the past three decades, numerous changes have been made in the system of the former order Erysiphales, in particular, in its generic composition; moreover, dozens of new species have been described. At the same time, many species of powdery mildew fungi were introduced to Europe, including Ukraine, in particular, from East Asia and North America. Thus, the species composition of powdery mildew fungi of Ukraine has undergone significant changes and requires a critical revision. Therefore, a series of relevant articles is planned to be published. This article, the first in the series, deals with the small genera Arthrocladiella and Blumeria. A list of species of these genera recorded in Ukraine (Arthrocladiella mougeotii, Blumeria avenae, B. bulbigera, B. dactylidis, B. graminicola, B. graminis, and B. hordei), their distribution by regions of Ukraine and a key for identification are provided. Arthrocladiella mougeotii was found to occur occasionally only in nine regions, mainly in the southern part of Ukraine, primarily in the forest-steppe and steppe zones and on the South Coast of Crimea. Blumeria avenae was recorded only in two regions, on the South Coast of Crimea and in Central Polissya and should be also considered rare in Ukraine. The remaining species were observed quite often and registered in 14–24 regions, while B. graminicola and B. graminis are regarded as the most common ones.