A study of the aquatic "Phycomycetes" of the gull lake area in Michigan / Adauto Ivo Milanez.

Tese (Ph.D.) Michigan State University, 1966

1. A total of 694 Aquatic "Phycomycetes", belonging to 64 species were isolated from 406 samples containing twigs, leaves and other material in water or from soil around the Gull Lake area by using different kinds of baits. 2. The most common fungi isolated belonged to the family Saprolegniaceae, comprising of 51.1% of the total number of isolates. 3. Among the 64 species isolated, 26 were new records for Michigan, including a new species of the genus Pythium. 4. The new records for the state are: Olpidium luxurians (first report from USA), Rhizophydium carpophilum, Rhizophydium vermicola, Rozella allomycis, Catenophlyctis variabilis, Allomyces anomalus, Allomyces arbuscula, Monoblepharis ovigera, Rhizidiomyces apophysatus, Rhizidiomyces bivellatus, Achlya ambisexualis, Achlya bisexualis, Achlya debaryana, Achlya intricata, Achlya oligacantha, Achlya recurva, Aphanomyces parasiticus, Brevilegnia unisperma, Geolegnia inflata, Saprolegnia torulosa, Saprolegnia turfosa, Pythium monospermum, Pythium terrestris n. sp. (echinulate oogonia), Apodachlya pyrifera P. macrosporangia, Lagenidium humanum and Olpidiopsis fusiformis. 5. The eccentric oospore grooup of Saprolegniaceae predominated all the year around, with a total percentage of 57,5%. 6. There was some increase of eccentric oospore group in the warmer months with a reverse for the centric and subcentric oospore group. 7. The water community: Dictyuchus monosporus, Blastocladia pringsheimii, Nowakowskiella elegans, Saprolegnia ferax, Zoophagus insidians and Pythium sp. 8. Soil communities include: Rhizophlyctis rosea, Saprolegnia sp., Allomyces anomalus, Nowakowskiella elegans, Saproolegnia ferax and Pythium sp. 9. Phlyctochytrium planicorne formed resting spores in oogonia and hyphae of Achlya oligacantha and Saprolegnia ferax, which are new hosts. 10 . Achlya flagellata, Achlya intricata and Achlya recurva are new hosts for Rhizophydium carpophilum. 11. Rhizophidium sp. is the first report of this genus on Hydrodictyon sp. 12. Achlya prolifera is a new host for Olpidipsis fusiformis and Aphanomyces parasiticus.