Achieving the objectives:
• The gene conferring resistance to SCN at the Rhg4 locus was identified by conducting complementation studies. Experiments showed that differences in the activity of the enzyme encoded by the gene between susceptible and resistant cultivars that help how the gene confers resistance.
• A mutagenized soybean population using Forrest was generated to help look for other genes in the Rhg-4 pathway. Several new mutant alleles in Rhg4 were found as well as two putative new mutants in genes potentially involved in SCN resistance.
• Resistance in Forrest requires both Rhg1 and Rhg4. Work was done to identify a gene at the Rgh1 locus that may work with Rhg4.
• Experiments aimed at understanding nematode genes involved with Rhg4 involved developing near-isogenic SCN populations selected on soybean recombinant inbred lines differing at the Rhg4 locus. After several years of selection, these populations are now being used for next generation sequencing to look at differences between the populations. This will serve as a platform for comparative studies among avirulent and virulent SCN populations.
• This work, which is potentially very valuable in protecting over a billion dollars per year in yield loss, has been protected where applicable by patents. Provisional patent applications were filed for the genes and methods of use to control SCN resistance at the Rhg1 and Rhg4 loci.
• Collaboration with the USB-funded Soybean Tissue Culture and Genetic Engineering Center resulted in complementation of SCN resistance in stable soybean transgenics using Rhg4. This will be expanded into different soybean genetic backgrounds.

Not achieving objectives:
• No issues.