Powdery mildew on Bougainvillea spectabilis in Mexico with a cryptic generic affinity

An asexual powdery mildew on Bougainvillea spectabilis resembles Ovulariopsis (anamorphic Phyllactinia and Pleochaeta), while its combination of sinuous to coiled conidiophores forming dimorphic conidia singly suggests a Pleochaeta anamorph. However, this severely contradicts the rDNA ITS molecular data. The Bougainvillea powdery mildew shows the closest genetic similarities (80-83% sequence homologies) with various Leveillula and Phyllactinia species (Phyllactinieae), whereas Pleochaeta species were not genetically close. These results suggest that the Bougainvillea powdery mildew has an affinity with tribe Phyllactinieae of the Erysiphaceae, but the percentage of genetic similarity is below the scope of generic limits in powdery mildew ITS data. Although a new genus may be involved, we cannot formally propose it based on a single sequence, an anamorph morphologically indistinguishable from Ovulariopsis, and an unknown teleomorph.