2014
Developing a Comprehensive Management Program for Foliar Diseases of Soybean (Year 3 of 2262)
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Contributor/Checkoff:
United Soybean Board
Category:
Sustainable Production
Keywords:
(none assigned)
Parent Project:
Developing a Comprehensive Management Program for Foliar Diseases of Soybean (Year 1 of 2262)
Lead Principal Investigator:
Ahmad Fakhoury, Southern Illinois University
Co-Principal Investigators:
X B Yang, Iowa State University
Clayton Hollier, Louisiana State University
Burton Bluhm, University of Arkansas
John Rupe, University of Arkansas
Carl Bradley, University of Kentucky
Grover Shannon, University of Missouri
Heather Kelly, University of Tennessee-Institute of Agriculture
Rouf Mian, USDA/ARS-Ohio State University
Alemu Mengistu, USDA/ARS-West Tennessee Experiment Station
+8 More
Project Code:
1420-532-5662
Contributing Organization (Checkoff):
United Soybean Board
(n/a)
Institution Funded:
Southern Illinois University
(n/a)
Brief Project Summary:

Unique Keywords:
#foliar diseases, cercospora leaf blight, frogeye leaf spot, soybean vein necrosis virus, #foliar fungicides, phomopsis seed decay, septoria brown spot, #soybean disease resistance, #soybean diseases
Information And Results
Project Deliverables

- Generation of draft genomes of C. sojina and C. kikuchii.
- The identification of genes or gene variants unique to specific races of the C. sojina.
- Complete an initial survey of strobilurin-fungicide-resistant strains of C. sojina across IL, IA, MO, TN, LA, and AR.
- Screening of a collection of commercial varieties and public lines for resistance to frogeye leaf spot.
- Determine yield loss curve for soybean vein necrosis

Final Project Results

Updated October 30, 2017:
Progress for each KPI is specified according to the numbered KPIs:
1. The genomes of C. sojina (frogeye leaf spot) and C. kikuchii (Cercospora leaf blight) were sequenced. The C. sojina genome is being formatted in preparation for public release. A publication describing the genome, as well as a web portal, is being prepared. Information from the sequences of both genomes will be used to identify genetic markers (e.g., SNPs) that can be used to assess pathogen diversity, discover genes involved in pathogenesis, and determine the genetic basis of race structure.
2. Isolates of C. sojina were collected from soybean fields with a high incidence of frogeye leaf spot in the Midwest (IL, IA, and MO) and the Midsouth (TN, LA, and AR). Also, a collection of C. kikuchii isolates was also built, and is currently housed and curated at the University of Arkansas.
3. An extensive collection of C. sojina (frogeye leaf spot) isolates were collected from AL, AR, IL, IN, KY, LA, MS,MO, NC, and TN. The isolates were assessed for resistance to strobilurin fungicides using an in-vitro petri dish assay, and results were published for public use. Likewise, field and lab studies are underway to determine efficacy of triazole fungicides upon frogeye leaf spot.
4. A website has been developed by Carl Bradley of IL that indicates the geographic areas where fungicide resistance to frogeye leaf spot is showing up.
5. Work is just underway in screening of commercial varieties in Illinois for their level of resistance to frogeye leaf spot and Septoria brown spot.
6. Two conventional, S08-18186 and S07-2680 and two Roundup Ready S08-9936RR1and S08-9727RR1 group V soybean lines with excellent resistance to frogeye leaf spot and soybean cyst nematode races 3 and 14 were developed. Each of these lines has the Rcs3 gene for broad resistance to frogeye races.
7. New sources of genetic resistance to frogeye leaf spot are being investigated. In one case, 50 frogeye leaf spot soybean accessions are being thoroughly genotyped to determine if they carry resistance genes other than the well-know source (Rcs3 gene).

View uploaded report Word file

Progress has been made to develop novel sources of resistance to Frogeye Leaf Spot. For the first time, resistance sources to Cercospora Leaf Blight have been initially identifed. New means to screen for these two major diseases are under development to enhance the breeding for resistance. Methods to detect fungicide resistance of Frogeye strains to foliar fungicides has been determined, that in turn, has led to establishment of a geographic map for incidence of fungicide resistance. Foliar fungicides are screened annually for efficacy against all major foliar diseases and published widely. A prediction system for Septoria brown spot has initially been developed.

The United Soybean Research Retention policy will display final reports with the project once completed but working files will be purged after three years. And financial information after seven years. All pertinent information is in the final report or if you want more information, please contact the project lead at your state soybean organization or principal investigator listed on the project.