A grant has been awarded to Dr. Donald Les and Mr. Michael Moody at the University of Connecticut to study the species relationships of plants in the angiosperm family Haloragaceae, which will enable them to identify invasive hybrid weeds, enhance viability of rare species and elucidate patterns of character evolution. Haloragaceae are distributed worldwide with approximately 120 species. They are extremely diverse, ranging from small trees to submerged aquatics. They are important economically as aquarium and water garden plants. Molecular data from both nuclear and chloroplast DNA will be analyzed using phylogenetic methods to infer relationships among the species. Molecular methods will also be used to determine parentages of hybrids. Because DNA profiles unique to each potentially parental species can be determined, plants sharing DNA markers from different species can be readily identified as hybrid offspring. DNA data will also be used to assess species limits of several rare species in North America and also Australia. Within this family the species look quite similar and often it is difficult to confidently distinguish those considered rare or endangered from those regarded as nuisance weeds. In order to make appropriate recommendations equally useful for conservation and management it is essential to identify the species accurately. Because these aquatic plants often display much variation in leaf shape, etc., molecular data will assure that plants are identified accurately. Dr. Les and Mr. Moody have shown for the first time that weedy watermilfoil (Myriophyllum) populations in North America have hybrid origins. Many state government agencies spend millions annually to combat watermilfoil weeds and some of these agencies already have solicited assistance to facilitate identification and improve their knowledge of invasive hybrid distributions. This work should provide important recommendations for invasive plant management, leading ultimately to more efficient aquatic weed control strategies.
