SIU student discovers fungi ‘good guys’ to fight SDS

Mirian Pimentel, a Southern Illinois University Carbondale (SIUC) agricultural sciences doctoral student, discovered a promising new tool to fight sudden death syndrome in soybeans. (Photo by Yenitza Melgoza, Southern Illinois University Communications and Marketing)

Beneficial fungi, already existing in midwestern soils, may help soybean growers fight sudden death syndrome thanks to a Southern Illinois University (SIU) doctoral student’s discovery.

Mirian Pimentel, originally from Brazil, explained her discovery came as part of a larger research project to identify fungi associated with diseased soybean seedlings. “Some of those organisms tried were known to be possible biological controls of the disease,” Pimentel told FarmWeek.

Proud of their student’s discovery, SIU School of Agricultural Professors Ahmad Fakhoury and Jason Bond noted the beneficial fungi were “not known in the soy world,” although scientific literature in other fields published information about them.

“When we deal with plant disease, we wonder, ‘Why is there more (disease) here or there?’ ” Bond said. “Mirian’s research has given us more insight. There is chemical warfare going on below the ground. This (discovery) is a good chunk of the puzzle.”

Pimentel explained she saw fungi organisms fight the disease. “It was really interesting to see the effect and the (fungi) aggression against the pathogen,” said the student, who began her research in 2017. “There is a great potential to optimize that effect.”

While “the good guys” are present in soil, they may not be in large enough numbers to protect soybean seedlings, Bond explained. One key will be making sure enough beneficial fungi are present at the right time because SDS starts early in the growing season although symptoms aren’t visible until late season, he said. Fungi population fluctuation may also partially explain why some areas of a field have more SDS issues than others, Bond added.

“We want to enhance the presence of the good guys in the soil, to make them more abundant,” said Fakhoury.

The potential for the disease to develop resistance to biological controls is less likely because of the complex interaction between the fungi and the disease, according to Fakhoury. The fungi “munches on the pathogen as well as enhances the plant growth,” he explained. “This complex mechanism can help the plant. ... The pathogen can be harder to counter (the fungi) because of this complexity.”

Among the next steps are studying management practices for the organisms and a potential partnership with company to develop a commercial product, according to Pimentel.

“We are still investigating (management practices) and are not sure when we will come up with the answers,” she said. Likewise, Pimentel had no estimate when a commercial product might be available, but she noted this would be an application of basic research.

“One thing we are looking at now, this is a different tool (for farmers),” Fakhoury said.

Pimentel, Fakhoury and Bond praised research funding from the soybean checkoff and growers who support their work. Funding was contributed through the United Soybean Board and the North Central Soybean Research Program to SIU.