Paul T. Madeira

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).

Genetic Variation in Melaleuca quinquenervia Affects the Biocontrol Agent Oxyops vitiosa1

Abstract Melaleuca was first imported into the United States during 1886, and introduction records suggest that at least six sources have contributed to extant populations in Florida. Allozyme analyses found substantial genetic variation within and among populations, contributing to geographic structuring of melaleuca in southern Florida. The presence and distribution of two chemical phenotypes (chemotypes) contributed to this variation. Performance of the melaleuca snout beetle imported as a biological control agent differed dramatically in laboratory studies depending on which chemotype it was fed, with larval survivorship and growth substantially greater on an (E)-nerolidol chemotype. We are currently investigating whether these differences can be detected in the field. Nomenclature: Melaleuca, Melaleuca quinquenervia (Cav.) Blake; melaleuca snout beetle, Oxyops vitiosa Pascoe. Additional index words: Allozyme analysis, biological control, chemotype, herbivory, invasion history, insect–plant interactions.

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

Abstract 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.