Chlamydospore formation, production, and nuclear status in Fusarium solani f.sp. glycines soybean sudden death syndrome-causing isolates

摘要

Six isolates of Fusarium solani f.sp. glycines that cause soyabean 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 1 chlamydospore. The percentage of chlamydospores produced differed significantly (P<0.0001) by incubation temperature and varied among fungal isolates. More chlamydospores formed at 30deg C followed by 25, 20 and 4degree C. Nuclear stained chlamydospores usually were uninucleate but occasionally multinucleate. Nuclei migrated from macroconidia into chlamydospores through germ tubes.