Database Research Summaries
Characterization of P. sojae and P. sansameana

calendar_today Year of Research: 2019
update Posted On: 04/05/2019
group Anne Dorrance, principal investigator, The Ohio State University; Alison Robertson, Iowa State University; Martin Chilvers, Michigan State University; Kiersten Wise, Purdue University; Emmanuel Byamukama, South Dakota State University; Santiago Mideros Mora, University of Illinois at Urbana-Champaign; James Kurle, Dean Malvick, University of Minnesota; Loren Giesler, University of Nebraska
bookmark North Central Soybean Research Program


Phytophthora sojae root and stem rot are present in many fields across the North Central region and Ontario, Canada, and had been managed successfully with the deployment of single resistance Rps genes. However, an increasing number of reports indicate that varieties with Rps genes are sold that are no longer effective.

Findings from a 2013 study indicate that a more thorough assessment of the P. sojae populations in the North Central region is needed. State populations of  P. sansameana will also be examined for host range, resistance in current soybean cultivars and efficacy of seed treatment fungicides.


After collecting and analyzing soil samples from nine states, multiple P. sojae isolates were recovered and some pathotyping has begun. The high number of locations in the survey provide current knowledge of the level of virulence against certain Rps genes, which is valuable in determining which Rps genes should be used to maintain effective levels of resistance.

2019 NCSRP Annual Report summary


Keeping up to date on how to ensure P. sojae root and stem rot is managed successfully will improve profitability of the North Central region soybean farmer. Improving plant health and reducing the incidences of disease will only improve plant health and yield.

For more information about this research project, please visit the National Soybean Checkoff Research Database.

Funded in part by the soybean checkoff.