Submitted to: Mycologia
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/10/1998
Publication Date: N/A
Interpretive Summary: Fusarium solani is a fungus that infects soybean roots and causes a disease of soybean referred to as sudden death syndrome (SDS). There has been very little information about this particular strain of the fungus that attacks soybeans. In this study, survival structures called chlamydospores were microscopically examined to determine how they form, and how their production varied over isolates and temperatures.In addition the nuclear status of macrocodidia (fungal spores) and chlamydospores were determined. It was found that the production of chlamydospores was prolific and even occurred at 4 C. The formation of chlamydospores occurred in different ways and was often dependent on temperature. The importance of this research is that it shows for the first time in F. solani SDS-causing isolates how chlamydospores formed and the nuclear status during formation. These results will impact researchers working on this fungus to help determine the role of these chlamydospores in plant infection, survival and dispersal.
Technical Abstract: Six isolates of Fusarium solani that cause soybean sudden death syndrome were examined for chlamydospore formation, production, and nuclear status. Chlamydospores formed from macroconidia either terminally, laterally by outward protrusion, or intercalarily. They also formed from germinated macroconidia and hyphae. Occasionally, a single macroconidium produced more than one chlamydospore. The percentage of chlamydospores produced differed significantly (P<0.0001) by incubation temperature and varied among fungal isolates. More chlamydospores formed at 30 C followed by 25 C, 20 C and 4 C. Nuclear staining revealed that chlamydospores usually were uninucleate but occasionally multinucleate. Nuclei migrated from macroconidia into the chlamydospores through germ tubes.