Abstract:
Nothopassalora personata is a fungal pathogen that causes late leaf spot of peanut. Because this fungus does not sporulate on media, laboratory inoculation studies rely on spores collected from field-infected peanuts as the inoculum source. Recent studies have shown that inoculum solutions prepared using a vacuum spore collector do not germinate as well as inoculum solutions prepared using sporulating leaf spots that have been cut from peanut tissues and dried. An experiment was conducted to see if the poor germination rates were caused by the vacuum process or by a toxic effect of the dissolvable capsule that the vacuumed spores are stored in. Treatments included a negative control inoculum solution (vacuumed spores prepared in a dissolvable capsule), a positive control solution (spores from dried leaf spots prepared in a microfuge tube), a solution prepared in the dissolvable capsule using spores from dried leaf spots, and a solution prepared in a microfuge tube using vacuumed spores. The results demonstrated a higher percent germination of N. personata spores from both unvacuumed treatments versus the ones that were vacuumed. There was no effect from the dissolvable capsule. These results suggest that the vacuum process reduces spore health.