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ARS Home » Southeast Area » Stoneville, Mississippi » Crop Genetics Research » Research » Publications at this Location » Publication #340473
Research Project: Genetics and Management of Newly Emerging Soybean Cyst Nematodes and Predominant Fungal Diseases for Sustainable Soybean Production

Location: Crop Genetics Research

Title: Coupling Spore Traps and Quantitative PCR Assays for Detection of Cercospora sojina, the Causal Agent of Soybean Frogeye Leaf Spot

Author
item LIN, BINBIN - University Of Tennessee
item YOUNG, HEATHER - University Of Tennessee
item YU, HAO - University Of Tennessee
item Mengistu, Alemu

Submitted to: National American Phytopathology Meetings
Publication Type: Abstract Only
Publication Acceptance Date: 6/30/2017
Publication Date: N/A
Citation: N/A

Interpretive Summary:

Technical Abstract: Frogeye leaf spot (FLS), caused by Cercospora sojina Hara, is a common disease of soybean. Significant yield losses (10–60%) have been attributed to FLS. We present a novel trapping approach using Vaseline coated slides placed at a 45° angle within a passive, wind-vane spore trap used in combination with real-time PCR to detect the presence of wind-blown inoculum. In 2016, multiple spore traps were deployed at 3 locations: (1) at Jackson, TN sampled twice weekly; (2) within tilled and no-till research plots sampled once weekly at Milan, TN; and (3) on the edge of large soybean plots in 4 different counties in TN sampled once weekly. DNA was extracted from Vaseline coated slides and qPCR was conducted using species primers/probes to estimate the number of spores based on a standard curve developed from known spore concentrations. FLS severity ratings were recorded at each reproductive growth stage using percent leaf area affected at locations 2 and 3. Comparing data from spore traps at location 1, there was no significant difference between sampling twice per week or once per week. There was no significant difference between spore amounts and disease severity collected from tilled and no-till plots. Spore trap data collected from different counties varied in trends and resulted in several major peaks of inoculum during the season most likely influenced by variety susceptibility to FLS, field history, and weather conditions. In combination with disease-conducive weather forecasting, variety and field history information, application of the assays may be helpful to time fungicide applications for disease management.