Evaluating novel germplasm for resistance to Phytophthora sojae

June 13, 2016 12:33 PM
Blog Post

It is hot here in Iowa...but not hot enough to discourage us from hand planting a soybean trial evaluating novel germplasm for resistance to Phytophthora root and stem rot (PRR) caused by P. sojae. PRR causes stand and yield losses every year throughout the U.S. 

My lab has been collaborating with several labs across the U.S. on a USDA-AFRI funded project on oomycete diseases of soybeans. Many of you are probably aware of the soybean seedling disease survey that was part of this project. Soybean researchers at Virginia Tech, Georgia, and Oregon State have been researching ways to develop  P. sojae-resistant soybeans. We get the fun part—to plant field trials and see if they actually are resistant to this pathogen. (The soybeans, right, not the researchers!)

This morning we headed out to the field, smiling and equipped with frozen bottles of water—ready to take on the heat. Nothing was going to stop us. We inoculated the seed furrow of the trial with millet seed that had been colonized by P. sojae. Then, we placed seed of each of the different lines into the furrow. 

Rachelle and Elizabeth are both doing their PhDs in my lab; and came out to help plant the trialSoybean seed placed in a seed furrow inoculated with millet seed colonized with P. sojae

The trial will be flooded over the next couple of days (by irrigation, and hopefully the forecasted storms), and we'll evaluate stands over the next few weeks. Remember,  P. sojae, is an oomycete that produces swimming zoospores, which infect the roots of soybean plants. We'll also be regularly checking the trial through the growing season for characteristic symptoms of PRR.




Alison Robertson Professor of Plant Pathology and Microbiology

Dr. Alison Robertson is a professor of plant pathology and microbiology. She provides extension education on the diagnosis and management of corn and soybean diseases. Her research interests include Pythium seedling disease of corn and soybean and Goss's wilt. Dr. Robertson received her bach...