Updated November 8, 2017:
This project was initiated preceding the incorporation and standardization of KPIs. The progress of objectives are as follows:
Achieving the objectives:
• Generating crosses and screening plants for more than 10 copies of Rhg1 is ongoing and several potential high copy number variants have been identified. The genetics and resistance characteristics of these lines are being evaluated.
• A robust TaqMan PCR assay was developed to identify each repeat unit sequence as well as the number of copies of reach repeat. This will be useful to breeders and companies who want to know exactly what SCN resistance is present in their lines. A preliminary patent application for the assay has filed.
• A putative line containing Rhg1 resistance from both Peking and PI88788 types is ongoing, but a line combining both resistances has not yet been identified.
• Fine mapping SCN resistance at 2 QTL from Glycine soja PI 468916 has progressed. Plants with recombinants close to cqSCN-006 and cqSCN-007 have been obtained and are being tested for SCN resistance. Candidate genes in the cqSCN-007 region were tested for function in SCN resistance using RNAi, one gene showed promising results, however fungal contamination of nematodes in the lab has hindered this work.
• Work to identify proteins in soybean that physically interact with Glyma18g02610 using metabolite profiling is ongoing.
• A paper on the evolution and selection of Rhg1 was published in Molecular Ecology.
The knowledge that the number of copies of the gene Rhg1 may have bearing on the magnitude of SCN resistance within a variety will make a difference in the future of how varieties are bred for improved SCN resistance.