ASSESSMENT OF GENETIC-VARIATION AND CLONALITY IN THE SEAGRASS POSIDONIA-AUSTRALIS USING RAPD AND ALLOZYME ANALYSIS

The genetic structure of a meadow of Posidonia australis Hook. f., an endemic seagrass from southern Australian coasts, was investigated at Warnbro Sound, Western Australia. A high level of genetic Variation as determined by allozyme and RAPD (random amplified polymorphic DNA) an alyses was found within a small area of the meadow. Allozyme analysis identified 15 four-locus genotypes from 43 samples (35%). RAPD analysi s identified 16 four-primer genotypes from 22 samples (73 %). The leve ls of genetic variation in P. australis are equivalent to or greater t han that observed in other hydrophilous species. The intrapopulational genetic Variation demonstrated in this study shows that meadows of P. australis need not be monoclonal in all cases.