Microsatellite loci identified in the seagrass Posidonia oceanica (L.) Delile

The detection of within- and between-population genetic variability in the Mediterranean seagrass Posidonia oceanica (L.) Delile, a difficult species to work with because Of its genotypic homogeneity, longevity, and clonal gr owth, has been achieved through the development of six polymorphic microsat ellite markers. The development of these markers is significant because pre vious studies indicate extreme levels of clonality in this seagrass species using minisatellite multilocus DNA fingerprints and RAPD markers. A furthe r eight microsatellite regions were found to be monomorphic, but wider and more extensive population surveys may find variation with these microsatell ite regions. Ten of the 14 microsatellite regions were observed to be prese nt in two Australian con generic species, P. australis and P. sinuosa, sugg esting that there is potential for their wide application in population gen etic analyses in this genus. These markers represent an important contribut ion to population genetic analysis in seagrasses, a group of considerable i nterest because of their important role in nearshore benthic marine communi ties worldwide.