Novel phytophthora sojae resistance genes for soybean cultivar development
Identification of 75 new resistance loci for Phytophthora root and stem rot in soybean using genome-wide association analyses across 1,813 plant introductions. Enables development of soybean cultivars with durable, broad-spectrum resistance to this major yield-limiting soil-borne pathogen.
Overview
Phytophthora sojae is a soil-borne pathogen that causes Phytophthora root and stem rot, one of the most economically damaging diseases affecting soybean production worldwide. The most effective management approach has been the deployment of soybean cultivars carrying single qualitative resistance genes (Rps genes). However, the high pathotypic and genetic diversity of P. sojae, combined with its rapid adaptation, limits the effective lifespan of any single Rps gene to roughly 8 to 20 years. This research directly addresses that challenge by identifying novel Rps genes that can be deployed in new cultivars to extend and diversify resistance.
The project applied three complementary genome-wide association analysis (GWA) strategies to identify both known and novel Rps loci. Phenotypic data from 1,813 soybean plant introductions across 16 panels were combined with genotypic data from the SoySNP50K iSelect BeadChip. Three statistical methods—compressed mixed linear model (CMLM), multi-locus mixed model (MLMM), and Fixed and random model Circulating Probability Unification (FarmCPU)—were used to ensure robust detection. The work identified 75 new Rps loci for P. sojae resistance, significantly expanding the pool of resistance sources available to soybean breeders.
Technical specifications
Research approach:
- Phenotypic screening of 1,813 soybean plant introductions (PIs) from 16 panels for resistance to P. sojae isolates
- Genotyping using the SoySNP50K iSelect BeadChip for high-density marker coverage
- Three GWA analytic methods applied: CMLM, MLMM, and FarmCPU, to cross-validate resistance loci
- Identification of 75 novel Rps loci for Phytophthora resistance
Planned next-stage validation:
- Selection of PIs showing resistant phenotypes that carry novel Rps loci
- Selection of maturity groups I, II, and III from among resistant PIs
- Crossing selected PIs with the P. sojae-susceptible cultivar "Williams"
- Generation of mapping populations following F1 confirmation
- Development of genetic markers to track and select progeny carrying the novel resistance loci
Technology readiness level
This research is at an early-to-mid stage of technology development. The genome-wide association analyses have been completed, and 75 novel Rps loci have been identified. The next phase involves validation through classical genetic approaches, including crosses with the susceptible "Williams" cultivar, population development, and marker-assisted selection to confirm the resistance conferred by the newly identified loci. Once validated, these novel Rps genes will be available for deployment in commercial soybean breeding programs, offering breeders a broader and more durable set of resistance options against P. sojae.
About The Ohio State University
The Ohio State University is a comprehensive public land‑grant research university in Columbus, serving one of the nation’s largest student populations and a broad research enterprise. Industry partners engage through an integrated academic medical center for clinical translation, a campus‑adjacent innovation district for co‑located projects, and a statewide extension network that pilots solutions across Ohio. Corporate engagement provides a single front door for sponsored research, talent pipelines, and streamlined agreements. Research is supported by competitive federal funding from agencies such as NIH, NSF, DOE, USDA, DoD, and NASA. A dedicated technology transfer office and venture support help protect IP, license technologies, and launch startups.
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