DISSERTATION RESEARCH: Evolution of Form and Function: Fruit Development in a Neotropical Lineage of Bignoniaceae

华盛顿大学的理查德·奥姆斯特德博士和苏珊·格罗斯女士获得了一项资助，用于研究中美洲一种哺乳动物分散水果的进化。研究组为十字花科(喇叭爬行科)中的一个部落新月花族的三个属。这些植物的近亲是Tabebuia属的一组树，这种树的干燥果实类似于喇叭攀缘植物的果实。这项研究的目标首先是确定被研究物种的进化关系，其次是分析发生了哪些变化，以从干燥和木质的水果中产生出适合动物品尝的水果。样本将在前往墨西哥和危地马拉的探险队中收集。DNA序列分析将被用来确定新月桂亚科和塔贝布亚科之间的亲缘关系。这项工作将在华盛顿大学进行。苏黎世大学将利用光学和电子显微镜技术研究果实组织中发生的变化。这项研究将加深我们对开花植物谱系中花和果实发育之间的关系以及重要功能性状的进化的理解。新月形目动物被认为是被现已灭绝的冰河时代哺乳动物吃掉的，这驱散了未消化的种子。目前还不知道现代有哪些动物在吃掉和散布水果。今天，新月虫亚科非常罕见，而且这些物种的分布非常局部化。它们不断面临着由于砍伐森林而灭绝的威胁。了解这些植物是如何进化的，是确定保护其种子传播器已经灭绝的植物物种的适当行动方案的一个步骤。

A grant has been awarded to Dr. Richard Olmstead and Ms. Susan Grose at the University of Washington to study the evolution of a mammal dispersed fruit in Central America. The study group is the three genera in the Crescentieae, a tribe in the family Bignoniaceae (Trumpet creeper family). The closest relative of these plants is a group of trees in the genus Tabebuia, a tree with dry fruits similar to those of Trumpet creeper. The goals of the research are first to determine the evolutionary relationships of the species under study, and second to analyse the changes that have taken place to produce a fruit palatable to animals from one that is dry and woody. Samples will be collected on an expedition to Mexico and Guatemala. DNA sequence analysis will be used to determine the relationships among the species of Crescentieae and Tabebuia. This work will take place at the University of Washington. The changes that have taken place in the fruit tissues will be studied at the University of Zurich using light and electron microscopy techniques.This study will enhance our understanding of the relationship between flower and fruit development and the evolution of functionally important traits in a lineage of flowering plants. The Crescentieae are thought to have been eaten by now extinct ice-age mammals, which dispersed the undigested seeds. It is not known which, if any, animals in modern times are eating and dispersing the fruits. Today, Crescentieae are very rare and the species have very localised distributions. They are constantly facing threats of extinction due to deforestation. Understanding how these plants evolved is one step in determining appropriate courses of action for conservation of plant species whose seed dispersers have gone extinct.