A survey of fungi associated with lesioned and chlorotic sago pondweed (Potamogeton pectinatus)

Isolations from 1000 Potamogeton pectinatus plants collected from six major stands in Back Bay, Virginia and 13 in Currituck Sound, North Carolina yielded Pythium spp. consistently and in relatively high frequency. Although specific determination of these isolates was unsuccessful, they were separated into three groups according to morphological and cultural characteristics. Rhizoctonia solani Kuehn was isolated in rare instances. In inoculation studies, isolates of R. solani were pathogenic to P. pectinatus, whereas inoculations with Pythium spp. proved inconclusive, even though one group of isolates exhibited pathogenic tendencies.