Now, Agricultural Research Service scientists have developed molecular sleuthing techniques to monitor these biocontrol agents once released into the environment. This has already resulted in DNA fingerprints for several isolates, or types, of Myrothecium verucarria, a soil fungus that kills morning glories.
Morning glory is a weed that plagues sugarcane and other crops.
Luster conducted the study with ARS plant pathologist Dana Berner and agronomist Rex Millhollon. Though used in the lab, DNA fingerprinting is intended to help scientists keep close tabs on the spore growth and spread, host range and effectiveness of biocontrol pathogens like Myrothecium once they've been released to control weeds. The technology also allows researchers to pinpoint and analyze particular DNA regions that can differentiate strains of the same fungal family, such as Puccinia carduorum and P. jacea, which attack musk thistle and yellow starthistle, respectively. They also examine the spores under a microscope, subject them to biochemical tests, and scrutinize infected plants for tell-tale disease symptoms. But the results can be ambiguous.