XVI International Botanical Congess

Unicellular autosporic coccoid algae are ubiquitous in freshwater ecosystems. However, little is known about the distribution and diversity of these organisms because of the simple morphology and small size. A hierarchal approach was used to examine the diversity of 80 winter isolates of autosporic coccoid algae from three shallow ND lakes. The methods included HPLC analysis of photosynthetic pigments, taxon-specific primers, and PCR-RFLP of the 18S rDNA. Fourteen 18S rDNA genotypes of coccoid trebouxiophytes, 3 genotypes of coccoid chlorophytes, and 1 genotype of coccoid eustigmatophyte were detected in the winter isolates. These results suggest a higher level of diversity in coccoid green algae than has been reported in regional floras. Currently, we are examining the seasonal distribution of these coccoid organisms.