The year 2000 saw a major revision of the taxonomy of the powdery mildews originally proposed by Braun (1987). The new monograph saw the recognition of the five major lineages of the Erysiphales therefore establishing the five ‘tribes’ (table 1).
Based on molecular analyses of the gene regions (the ITS region, as well as 18S and 28S rDNA) and superficial analyses of conidial surface patterns, discovered by Cook et al. (1997) under the SEM, these new systematics seem to reflect the diversity of powdery mildews.
Importantly, distinguishing characteristics of the Erysiphales seem to comply with this new classification. With all but three of the genera infecting their respective host plants ectoparasitically (fig. 1), those with an endoparasitic (or partially endoparasitic) nature are grouped together within the Phyllactinieae (the Leveillula, Phyllactinia and Pleochaeta).
Next we will see how other features such as appendage morphology, number of asci per chasmothecium and conidiogenesis type also fit into this updated taxonomy.
BRAUN, U. 1987. A monograph of the Erysiphales powdery mildews.
COOK, R. T. A., INMAN, A. J. & BILLINGS, C. 1997. Identification and classification of powdery mildew anamorphs using light and scanning electron microscopy and host range data. Mycological Research, 101, 975-1002.
TAKAMATSU, S. 2013. Molecular phylogeny reveals phenotypic evolution of powdery mildews (Erysiphales, Ascomycota). Journal of General Plant Pathology (2013): 1-9.