Intersimple sequence repeats (ISSR) molecular markers to distinguish gametophytes of Batrachospermum boryanum (Batrachospermales, Rhodophyta)

Genetic variability among individual gametophytes of a single population of Batrachospermum boryanum Sirodot was investigated using the relatively new molecular marker technique of intersimple sequence repeats (ISSR). Indepen dent PCR amplifications with five individual primers yielded 57 distinct ba nds from 15 individuals. Each gametophyte was distinct in its overall bandi ng pattern. Percent similarity between individuals romped from 41% to 82%, with most pairwise comparisons being between 60% to 80%. The neighbor-joini ng tree constructed from the data showed little population structure based on location from upstream to downstream. Interestingly, the individuals fro m the most upstream microsite were most closely related to the individuals from the furthest downstream microsite, suggesting either high gene flow or dispersal. ISSR molecular markers appear to be useful in distinguishing in dividual gametophytes within a population and may prove to be valuable in p hylogeographic and other macroalgal studies.