In this project we will carefully describe the biology of the SCN/soybean interaction, focusing on the mechanism SCN uses to evade or suppress host plant resistance. This project will develop a novel strategy to manage virulent SCN by producing a rapid low-cost virulence assay validated on various unrelated SCN field populations. The virulence assay coupled with the knowledge of which SCN resistant plants suppress specific SCN virulence genes will allow the development of custom rotational strategies that will drive SCN populations below damage thresholds. The rapid virulence assay will act as an early warning system to alert growers when they have damaging levels of virulent SCN, which will allow the timely deployment of management strategies to avoid soybean damage. Finally, because the SCN virulence proteins appear to physically bind to soybean resistant proteins, these nematode virulence genes can be used to identify new sources of SCN resistance genes that will be molecularly optimized for maximal protection of the plant.
While our work, over the next year may not develop a DNA-based virulence test for all known Hg Types, we hope to have assays for some of the most common virulence types (Hg-type 1, 2) by the end of the project. This project addresses strategic topic areas 5, 6, 7, 8 and 9 described in the RFP.
• Extensive field-testing will be completed to correlate one SCN virulence assay to Hg- Type.
• The percentage of field SCN virulent populations that use the same mechanism for over coming a given source of SCN resistance will be determined.
• A working virulence assay, validated for two more SCN virulence genes, on unrelated SCN populations, for a common Hg type will be generated.
• Soybean resistance gene combinations that consistently amplify and suppress the SCN SNARE-like virulence gene will be identified.
• A list of soybean proteins that physically interact with SCN virulence proteins will be identified.