Microsatellite Markers for Population Genetic Applications in the Domoic Acid-producing Diatom Pseudo-nitzschia australis Frenguelli (Bacillariophyceae).

Microsatellitesare commonly used markers in population genetics and are increasingly being employed to determine population structure in phytoplankton populations. We have developed seven polymorphic microsatellitemarkers for the domoic-acid producing diatom Pseudo-nitzschiaaustralis. Using these markers, thirty P. australis isolates were genotyped, 10 isolates were from Monterey Bay, California and 20 were from off the northern coast of Oregon. The number of alleles per locus ranged from two to eight and observed heterozygosities ranged from 0.11 to 0.70. All but two of the isolates were genetically distinct and initial population differentiation analysis indicated no significant differences between the Pacific Northwest isolates and the Monterey Bay isolates. Pseudo-nitzschiaaustralis microsatellitesappear to be species specific based on cross amplification tests with Pseudo-nitzschiafraudulenta (Cleve) Hasle, Pseudo-nitzschia seriata(Cleve) H.Peragallo, Pseudo-nitzschiapungens (Grunow ex Cleve) and Pseudo-nitzschiamultiseries (Hasle) Hasle.