Detection of in Air Samples by Quantitative PCR.

Detection and quantification of pathogen propagules in the air or other environmental samples is facilitated by culture-independent assays. We developed a quantitative PCR assay for the hop powdery mildew fungus, , for detection of the organism from air samples. The assay uses primers and a TaqMan probe designed to target species-specific sequences in the 28S large subunit of the nuclear ribosomal DNA.

A Multiplex TaqMan qPCR Assay for Detection and Quantification of Clade 1 and Clade 2 Isolates of and .

The ability to detect and quantify aerially dispersed plant pathogens is essential for developing effective disease control measures and epidemiological models that optimize the timing for control. There is an acute need for managing the downy mildew pathogens infecting cucurbits and hop incited by members of the genus ( clade 1 and 2 isolates and , respectively). A highly specific multiplex TaqMan quantitative polymerase chain reaction (PCR) assay targeting unique sequences in the pathogens' mitochondrial genomes was developed that enables detection of all three taxa in a single multiplexed amplification.

Genotyping-by-Sequencing Reveals Fine-Scale Differentiation in Populations of .

is the causal agent of downy mildew of hop, one of the most important diseases of this plant and a limiting factor for production of susceptible cultivars in certain environments. The degree of genetic diversity and population differentiation within and among . populations at multiple spatial scales was quantified using genotyping-by-sequencing to test the hypothesis that populations of .