David Gadoury

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Erysiphe necator is an obligate biotroph capable of infecting three genera within the Vitaceae (Vitis, Parthenocissus, and Ampelopsis). The pathogen inhabits a niche unique to most powdery mildews, i.e., wholly external mycelial growth supported by haustoria within the subtending host epidermal cells. This growth habit coupled with its biotrophic reliance(More)
Marker-assisted selection (MAS) is often employed in crop breeding programs to accelerate and enhance cultivar development, via selection during the juvenile phase and parental selection prior to crossing. Next-generation sequencing and its derivative technologies have been used for genome-wide molecular marker discovery. To bridge the gap between marker(More)
Use of resistant cultivars represent an efficient control measure for lettuce downy mildew (Bremia lactucae), although the durability of presently deployed resistance genes remains uncertain. Our objective was to document the pathogenic diversity of B. lactucae isolates in Norway. A total of 69 isolates of B. lactucae were collected between 2001 and 2006(More)
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(More)
Quantitative trait locus (QTL) identification in perennial fruit crops is impeded largely by their lengthy generation time, resulting in costly and labor-intensive maintenance of breeding programs. In a grapevine (genus Vitis) breeding program, although experimental families are typically unreplicated, the genetic backgrounds may contain similar progenitors(More)
The fungal pathogen that causes strawberry powdery mildew (Podosphaera aphanis) can survive on senescent green leaves of overwintering plants in perennial production systems, as cryptic infection on nursery stock deployed in annual or perennial production systems, and as small spherical fruiting structures called chasmothecia that normally function as(More)
1 Grapevine powdery mildew (PM) is an annual occurrence in most New York vineyards, but its severity can vary year to year. Drawing on 22 years of historical data on powdery mildew epidemics and weather, we have built a model to predict the risk of powdery mildew pressure in a given year. The model uses two key observations about powdery mildew biology.(More)