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ARS Home » Pacific West Area » Corvallis, Oregon » Horticultural Crops Research Unit » Research » Publications at this Location » Publication #182610
Title: QUANTIFICATION OF AIRBORNE HOP POWDERY MILDEW INOCULUM, A MOLECULAR APPROACH.

Author
item PEETZ, A - OREGON STATE UNIVERSITY
item Mahaffee, Walter - Walt
item GROVE, G - WASHINGTON STATE UNIV

Submitted to: Phytopathology
Publication Type: Abstract Only
Publication Acceptance Date: 6/29/2005
Publication Date: 10/5/2005
Citation: Peetz, A.B., Mahaffee, W.F., Grove, G.G. 2005. Quantification of airborne hop powdery mildew inoculum, a molecular approach.. Phytopathology.

Interpretive Summary:

Technical Abstract: Current disease forecasting models for Hop powdery mildew, Podosphaera macularis, assume inoculum presence. Evidence suggests that temperature fluctuations influence inoculum availability. Therefore, knowledge of inoculum presence and density and their relationship to environmental conditions may increase management efficacy by reducing pesticide use and cost of crop production. Primers designed to the internal transcribed spacer region of P. macularis ribosomal DNA have made inoculum detection possible using conventional and quantitative SYBR Green PCR methods. DNA extracted from conidia impinged on glass rods coated in silicon grease has been used as template for qPCR and we have successfully detected greater than or equal to 100 spores. However, background SYBR green fluorescence unrelated to primer, template, or magnesium ion concentration is reducing sensitivity. Various fluorescent probes are being pursued as a means of increasing stringency and efficiency of the qPCR reaction.