Genetic diversity of Halodule wrightii using random amplified polymorphic DNA

The genetic diversity of three populations of the seagrass Halodule wrightii from Christmas Bay, a Flour Bluff cooling pond in Corpus Christi, and Florida Bay was determined using random amplified polymorphic DNA (RAPD). The purpose was to determine if these populations were multiclonal or monoclonal and to see if any genotypes were shared between them. Approximately 72% of the loci were polymorphic and reproducible. Corpus Christi had the highest average heterozygosity. An analysis of molecular variance (AMOVA) showed that approximately 60% of genetic variation was found among populations indicating a highly structured species. AMOVA also showed that 10% of the genetic variation may be due to geographic differences. UPGMA cluster analysis showed every individual except one clustered within its population. All individuals appeared to have unique genotypes. Corpus Christi clustered more closely to Florida Bay than to Christmas Bay. The similar habitats of Corpus Christi and Florida Bay may be acting as a selection agent causing these unexpected results. (C) 2002 Elsevier Science B.V All rights reserved.