Randy LaBauve, Gould, Frances I., Blanchard, Tobie M. | 11/9/2017 7:18:36 PM
The LSU AgCenter soybean breeding program is developing and evaluating lines that offer resistance to Cercospora leaf blight.
This strain of the Cercospora fungus, now very destructive to soybeans, has been around for more than 60 years in the United States.
“We have three lines that look pretty good in regional trials against Cercospora in multiple locations in Louisiana, Mississippi, Arkansas and Alabama,” said Blair Buckley, principal investigator for the AgCenter soybean breeding program and associate director of the Red River Research Station in Bossier City. “There’s some encouragement that some of these might hold up on a regional basis.”
Researchers are looking for crosses resistant to Cercospora leaf blight that produce good yields. AgCenter plant pathologists have had a difficult time working with the pathogen because it rapidly adapts to different plant varieties and develops resistance to chemicals, Buckley said.
“Most of our crosses have that in mind, and some seem to be better than others,” he said. “We have a pool of varieties that are showing pretty good tolerance.”
Cercospora is considered a late-season disease — symptoms typically don’t appear until later growth stages.
Researchers are also working on flood- and drought-resistance projects that also tie in to better soybeans.
There is some overlap between different projects, which helps researchers crossbreed better overall varieties, Buckley said. The AgCenter has been part of a collaborative USDA breeding project that incorporates flood-resistant wild soybeans (Glycine soja) with cultivated soybeans (Glycine max) to form potentially successful new plant materials.
“When evaluating lines of plants for flood tolerance, for instance, one parent could be tolerant to flood water plus another parent with resistance to Cercospora leaf blight,” Buckley said.
“Whether we have complete resistance or not, some type of improvement can be a beneficial step in the right direction,” he said. “We like to see about five consistent years of plants with resistance to Cercospora in different locations in the state and regionally.”
The LSU AgCenter and the LSU College of Agriculture