Project Number: 3611-22000-019-00
Project Type: Appropriated

Start Date: Apr 30, 2007
End Date: Apr 29, 2012

Objective:
1: Develop and use quantitative methodologies to detect, identify, and characterize soybean pathogens and monitor the spread of disease epidemics. 2: Identify viral and host determinants of horizontal and vertical transmission of soybean viruses. 3: Identify and improve germplasm with soybean disease resistance using phenotypic and marker-assisted selection. 4: Develop and improve integrated strategies for sustainable disease management in soybean. Sub-objectives: a. Determine the efficacy of fungicides and optimize cultural practices for the management of soybean rust. b. Develop and validate biological control protocols for bacterial agents against soybean cyst nematode.

Approach:
1) Pathogens will be collected from diseased plants, air, soil, and water and phenotypically and molecularly characterized to identify nucleotide sequences that will be used to quantitatively identify pathogenic organisms and to determine genetic variability of pathogens. 2) To identify viral determinants of transmission, transmission phenotypes of chimeric viruses constructed from viruses differing in transmission properties will be evaluated; regions of the soybean genome involved in seed transmission will be identified using molecular markers and populations of soybean plants differing in transmission of virus through seed. 3) Potential sources of soybean resistance genes and populations segregating for resistance will be evaluated in nurseries and other sites appropriate for resistance screening tests. 4) Soybean germplasm accessions with resistance will be crossed with selected cultivars and lines to create populations used for inheritance and mapping studies. Fungicide trials will evaluate fungicide efficacy, sprayer/delivery technology, timing and frequency of applications, possible interactions between fungicides and soybean genotypes, row spacing, irrigation, and plant architecture on soybean rust infection. Molecular techniques will be developed to identify and quantify obligately parasitic, biological control bacteria in soybean cyst nematode populations and in field soil and culture of bacteria will be attempted using proprietary technology.