Integration of five Southeast Asian accessions into the world-wide phenetic relationships of Hydrilla verticillata as elucidated by random amplified polymorphic DNA analysis

Random amplified polymorphic DNA (RAPD) markers were analyzed for five new accessions of Hydrilla verticillata (L.f.) Royle collected from southeast Asia (Vietnam and Thailand). These were compared to 12 accessions that had been analyzed in a previous study. Five primers produced 91 loci which were used to calculate the Dice similarity metric which was in turn used to compare the accessions phenetically using both the neighbor-joining algorithm and the unweighted pair-group arithmetic average clustering (UPGMA) method. The US dioecious accessions, as previously, clustered closest to a plant from Bangalore, India. The US monoecious accessions again clustered with a Seoul, Korean accession. The five Southeast Asian accessions clustered loosely near accessions from Pinang Island, Malaysia, Rawa Pening, Indonesia and Tainan, Taiwan, but showed less phenetic similarity to the Asian accessions. (C) 1999 Elsevier Science B.V. All rights reserved.