Random amplified polymorphic DNA analysis of the phenetic relationships among world-wide accessions of Hydrilla verticillata

Abstract

The phenetic relationships among forty-four accessions of Hydrilla verticillata from various regions of the world were determined using random amplified polymorphic DNA (RAPD) analysis of bulked genomic samples. Five primers were used producing a total of 85 resolvable, polymorphic bands. The accessions were compared using Gower and Dice metrics, clustered using unweighted pair-group arithmetic average clustering (UPGMA) and consensus algorithms, and factored using principal coordinate analysis. Four major clusters (Asian, Australian, Indonesian, monoecious U.S.) and one minor outlier cluster (Japan/Poland) were identified. The U.S. dioecious accessions formed a group closest to an accession from Bangalore, India, possibly lending credence to historical reports that it was imported from Sri Lanka. The U.S. monoecious plants cluster with an accession from Seoul, Korea. Accessions from Taiwan, Burundi, and Panama join the Asian cluster late. The New Zealand accessions cluster loosely with those from Australia. The use of band intensity in combination with the Gower similarity coefficient generated a cophenetic correlation coefficient (similarity matrix vs. UPGMA matrix) of r = 0.92, superior to that for the corresponding Dice metric ( r = 0.85).