A collection of four clonal isolates of Podosphaera aphanis was heterothallic and was composed of two mutually exclusive mating types. Cleistothecial initials approximately 20 to 30 microm in diameter were observed within 7 to 14 days after pairing of compatible isolates and developed into morphologically mature ascocarps within 4 weeks after initiation on both potted plants maintained in isola...

Diseases of the United States Department of Agriculture. It has been continued at the University of Michigan. Paper of the Department of Botany and of the University Herbarium, University of Michigan No. 397. 1 Mains, E. B., "Rye Resistant to Leaf Rust, Stem Rust and Powdery Mildew," Jour. Agr. Res., 32, 201-221 (1926). 2 Mains, E. B., and Dietz, S. M., "Physiologic Forms of Barley Mildew, Erys...

Pseudozyma spp. are yeast-like fungi, classified in the Ustilaginales, which are mostly epiphytic or saprophytic and are not pathogenic to plants. Several Pseudozyma species have been reported to exhibit biological activity against powdery mildews. However, previous studies have reported that Pseudozyma aphidis, which can colonize plant surfaces, is not associated with the collapse of powdery m...

Together with longer production periods, the commercial transition to day-neutral strawberry (Fragaria × ananassa) varieties has favored the development of diseases such as powdery mildew (Podosphaera aphanis) that thrives in late summer-early fall. In an attempt to find alternative solutions to fungicides currently employed to curb the disease, we wanted to investigate the potential of silicon...

Powdery mildew is an important disease of cereals. It is caused by one species, Blumeria graminis, which is divided into formae speciales each of which is highly specialized to one host. Recently, a new form capable of growing on triticale (B.g. triticale) has emerged through hybridization between wheat and rye mildews (B.g. tritici and B.g. secalis, respectively). In this work, we used RNA seq...

Initiation of asexual sporulation in powdery mildews is preceded by a period of superficial vegetative growth of mildew colonies. We found evidence of a quorum-sensing signal in Erysiphe necator that was promulgated at the colony center and stimulated conidiation throughout the colony. Removal of the colony center after putative signal promulgation had no impact upon timing of sporulation by 48...

How plants coordinate developmental processes and environmental stress responses is a pressing question. Here, we show that Arabidopsis (Arabidopsis thaliana) Rho of Plants6 (AtROP6) integrates developmental and pathogen response signaling. AtROP6 expression is induced by auxin and detected in the root meristem, lateral root initials, and leaf hydathodes. Plants expressing a dominant negative A...

ABSTRACT A polymerase chain reaction (PCR) assay employing species-specific primers was developed to differentiate Erysiphe necator from other powdery mildews common in the northwest United States. DNA was extracted from mycelia, conidia, and/or chasmothecia that were collected from grape leaves with a Burkard cyclonic surface sampler. To differentiate E. necator from other erysiphaeceous fungi...

BACKGROUND Molecular tools may greatly improve our understanding of pathogen evolution and epidemiology but technical constraints have hindered the development of genetic resources for parasites compared to free-living organisms. This study aims at developing molecular tools for Podosphaera plantaginis, an obligate fungal pathogen of Plantago lanceolata. This interaction has been intensively st...

Powdery mildews (Erysiphales) are economically important plant pathogens that attack many agricultural crops. Conventional management strategies involving fungicide application face challenges, including the evolution of resistance and concerns over impacts on non-target organisms, that call for investigation of more sustainable alternatives. Mycophagous ladybird beetles (Coleoptera: Coccinelli...