DISSERTATION RESEARCH: Systematics of Haloragaceae R. Br. Emphasizing the Aquatic Genus Myriophylum: Phylogeny, Hybridization, and Character Evolution

康涅狄格大学的Donald Les博士和Michael Moody先生获得了一笔资金，用于研究被子植物Haloragaceae家族植物的物种关系，这将使他们能够识别入侵的杂交杂草，提高稀有物种的生存能力，并阐明性状进化的模式。盐菜科分布在世界各地，约有120种。它们种类繁多，从小树到水下生物都有。作为水族和水上园林植物具有重要的经济价值。来自细胞核和叶绿体DNA的分子数据将使用系统发育方法进行分析，以推断物种之间的关系。分子方法也将用于确定杂交后代的亲缘关系。由于可以确定每个潜在亲本物种的独特DNA图谱，因此共享不同物种DNA标记的植物可以很容易地识别为杂交后代。DNA数据还将用于评估北美和澳大利亚几种稀有物种的物种限制。在这个科的物种看起来很相似，通常很难自信地区分那些被认为是稀有或濒危的杂草和那些被认为是讨厌的杂草。为了提出对保护和管理同样有用的适当建议，必须准确地确定物种。由于这些水生植物通常在叶片形状等方面表现出很大的差异，因此分子数据将确保植物的准确识别。莱斯博士和穆迪先生首次表明，北美的水藻（肉豆科）种群具有杂交起源。许多州政府机构每年花费数百万美元来对抗水草，其中一些机构已经寻求帮助，以促进识别和提高他们对入侵杂交分布的了解。该研究为入侵植物管理提供了重要建议，最终导致更有效的水生杂草控制策略。

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.