Dissertation Research: Systematics of Erythrina (Leguminosae) and the Evolution of Pollination Systems

在导师杰弗里·道尔博士的指导下， 康奈尔大学的研究生安妮·布鲁诺将研究 分子系统学、形态学和传粉生物学 豆科刺桐属的一个种。 有几个种类是 在热带地区作为行道树栽培，用作活栅栏， 或作为遮荫树种植在咖啡和可可种植园。 所有 刺桐属的种类有红色或橙子的花， 蜂鸟或栖息鸟（雀形目）。 由栖息的鸟类授粉的物种有宽而张开的花朵 朝向枝或分支尖的;种 由蜂鸟授粉，花有窄管， 只有鸟儿才能吃到花蜜， 影响授粉。 蜂鸟授粉被认为是 比栖息鸟类的授粉更加专业化，但这 从未被严格测试过。 相当大的生物和园艺兴趣， 导致了几乎所有112种物种的可用性， 在生活收藏中。 实验室工作将侧重于 物种多样性的分子标记，从 叶绿体DNA和核核糖体DNA的分析。 组合 分子和形态学证据将产生一个强大的 系统发育树。 实地工作将记录 那些尚未研究的物种的特定传粉者。 然后研究人员可以确定进化关系 蜂鸟和栖息鸟类之间的授粉物种， 测试进化变化是一次还是多次发生 这一属的物种之间的时间。

Under the guidance of faculty adviser Dr. Jeffrey Doyle, graduate student Anne Bruneau of Cornell University will study the molecular systematics, morphology, and pollination biology of species in the legume genus Erythrina. Several species are cultivated as street trees in the tropics, used as living fences, or planted as shade trees in coffee and cacao plantations. All Erythrina species have red or orange flowers and are pollinated by either hummingbirds or perching birds (order Passeriformes). Species pollinated by perching birds have wide, gaping flowers that are oriented toward branches or branch tips; species pollinated by hummingbirds have narrow-tubed flowers that face outwards and only birds that hover can obtain nectar, and thereby effect pollination. Hummingbird pollination has been considered more specialized than pollination by perching birds, but this has never been critically tested. Considerable biological and horticultural interest has resulted in the availability of nearly all 112 species in the genus in living collections. Laboratory work will focus on molecular markers of species diversification, obtained from analyses of chloroplast DNA and nuclear ribosomal DNA. Combined molecular and morphological evidence will produce a robust phylogenetic tree for the group. Field work will document the specific pollinators of those remaining species not yet studied. The researchers can then determine the evolutionary relationships between hummingbird- and perching bird-pollinated species and test whether the evolutionary change occurred once or several times among species of this genus.