Collaborative Research: Generic Relationships within Subfamily Bromelioideae (Bromeliaceae)

怀俄明大学的布朗博士和霍普学院的埃文斯博士获得了一笔资助，用于研究热带植物科凤梨科亚科成员之间的进化关系。凤梨科有30属750种，是凤梨科中了解最少的亚科。凤梨亚科中几乎三分之一的物种由Aechmea属代表，这是一个非常可变的，几乎可以肯定是人工属。凤梨亚科中有几个属与凤梨亚属仅有一两个性状的差异，属间的形态界限非常模糊。aecmea是一个由多达20个凤梨科属组成的复合体的核心，其进化关系和系统分类学完全混乱。本项目的主要目标是利用形态学和分子（DNA序列）数据来研究凤梨亚科内的关系，重点研究凤梨亚属及其密切相关的属。在密集的野外研究中，将收集单株植物的形态信息。由于花的特征在正常的压榨和干燥过程中保存得很差，观察活的和/或液体保存的材料对于成功的系统发育分析至关重要。系统发育分析使用最大简约的方法将进行分类单元的特征数据矩阵产生在这个密集的再分析形态。将从用于形态学研究的同一个体中收集三个非编码区（两个叶绿体基因间间隔区，psbA-trnH和trl - trnf，以及核糖体内部转录间隔区）的DNA序列数据。分子数据的系统发育分析将提供形态系统发育的独立评估以及检查特定形态特征进化的工具。多数据集的整合目前是系统学中一个备受讨论和争论的领域，我们将探讨几种比较和整合分子和形态数据的方法。该研究将为以下几个更广泛的科学和教育目标做出重大贡献：1)它代表了首次尝试从明确的系统发育范式中发展关于凤梨科凤梨亚科系统发育关系的假设。2)对巴西大西洋森林生物群系中一个重要的生态类群（凤梨亚科）的生物多样性文献记录有重要贡献。3)从生态学角度来说，包括凤梨亚科大部分成员的库形凤梨亚科是维持生物多样性的关键物种。它们是树冠层自由水的重要资源，为代表所有生命王国的许多不同生物提供觅食、繁殖和栖息地。由此产生的系统发育假说将对生物学家研究多样性、生物地理学和利用凤梨菌池的任何生物可能的共同进化模式具有重要意义。4)美国和巴西的学生都将接受现代系统实践和理论的培训。5)该项目将改善巴西一所重要大学的专业植物系统学研究和教学基础设施。收集到的DNA样本和序列将提供给其他研究人员。7)该项目将有助于促进未来美国和巴西系统性和生物多样性相关的合作研究和教育。

A grant has been awarded to Dr. Brown at the University of Wyoming and Dr. Evans at Hope College to examine evolutionary relationships among members of the tropical plant family Bromeliaceae subfamily Bromelioideae. The Bromelioideae, with 30 genera and about 750 species, is the most poorly understood subfamily in Bromeliaceae. Almost a third of the species in subfamily Bromelioideae are represented by the genus Aechmea, an extremely variable, and almost certainly artificial genus. Several genera in Bromelioideae differ from Aechmea by only one or two characters, and the morphological boundaries among genera are very poorly defined. Aechmea forms the core of a complex of as many as 20 Bromelioideae genera for which evolutionary relationships and systematics are in complete disarray. The primary goal of this project is to utilize morphological and molecular (DNA sequence) data to examine relationships within Bromelioideae, with an emphasis on Aechmea and closely related genera. Morphological information from individual plants will be collected during intensive field studies. Because floral characteristics are poorly preserved in this family during the normal pressing and drying process, observation of live and/or liquid preserved material is critical for successful phylogenetic analysis. Phylogenetic analyses using maximum-parsimony methods will be conducted on the taxon by character data matrices produced in this intensive reanalysis of morphology. DNA sequence data from three non-coding regions (two chloroplast intergenic spacers, psbA-trnH and trnL-trnF, and nuclear ribosomal internal transcribed spacer regions) will be collected from the same individuals used for morphological studies. Phylogenetic analyses of the molecular data will provide an independent assessment of the morphological phylogenies as well as a tool to examine the evolution of specific morphological characters. Integration of multiple data sets is currently an area of much discussion and debate in systematics, and several methods for comparing and integrating the molecular and morphological data will be explored. The proposed research will contribute significanly to several broader sceintific and educational goals, as follows: 1) It represents the first attempt to develop hypotheses of phylogenetic relationships within Bromeliaceae subfamily Bromelioideae from within an explicit phylogenetic paradigm. 2) It will make a significant contribution to biodiversity documentation for an ecologically important taxon (Bromelioideae) in one of the most endangered, yet biotically diverse biomes on Earth, the Atlantic Forest Biome of Brazil. 3) Ecologically, tank-forming bromeliads, which include most members of Bromelioideae, are keystone species in biodiversity maintenance. They are an important resource for free-water in the canopy, and provide feeding sites, breeding sites, and habitat for many diverse organisms that represent all Kingdoms of life. The resulting phylogenetic hypotheses will be important to biologists studying diversification, biogeography, and possible co-evolutionary patterns of any of the organisms that utilize bromeliad tanks. 4) Both U.S. and Brazilian students will be trained in modern systematic practice and theory. 5) The project will improve professional botanical systematics research and teaching infrastructure at an important Brazilian university. 6) DNA samples and sequences collected will be made available to other researchers. 7) The project will help to stimulate future collaborative U.S. - Brazil systematic and biodiversity-related research and education.