Phylogenetic Systematics of Moraceae: Inflorescence Evolution and the Origin of a Pollination Mutualism

明尼苏达大学George Weblen博士的工作使用桑科(桑科)这一古老开花植物谱系中活着的成员的DNA序列，研究了桑科的进化史。世界上有1000多种桑科植物，包括无花果、桑树、菠萝蜜和面包果等具有重要经济价值的水果。在桑科植物中，无花果(榕属)因其与无花果黄蜂的复杂相互作用而成为生态学和进化研究的主要焦点。以无花果种子为食的专门化黄蜂是700多种无花果的唯一传粉者。无花果和它们的黄蜂之间的互利关系激发了许多关于共同进化的研究，共同进化是两个物种经历基因变化以应对对方的过程。无花果授粉的生态学研究促进了我们对共同进化的理解，但导致无花果授粉的起源和进化阶段实际上仍然未知。该项目使用DNA测序和系统发育分析的新工具来探索桑树家族的早期历史，并识别无花果的近亲。东半球热带地区的野外工作将集中在几个桑科植物的授粉生物学上。以这种方式重建多样性模式，可以检验关于独特的无花果授粉综合征起源的理论，并提高我们对花卉进化总体趋势的理解。该项目将显著扩展我们对生命树的一个重要分支的分类学和系统发育知识。桑科具有重要经济价值的成员包括观赏和食用无花果(Ficus)、面包果和菠萝蜜(Artocarpus)、作为纤维来源的纸皮桑树(Broussonetia)和主要的热带木材面包坚果(Brosimum)。桑树作为蚕蛾的主要食物来源，在蚕丝生产中也起着关键作用。了解这些植物的遗传关系对于它们的可持续利用和保护非常重要。此外，这项研究还提供了高级研究生培训的机会，将最先进的分子技术与基于博物馆收藏品的方法相结合，以研究生物多样性。

Weiblen0128833Work by Dr. George Weiblen at the University of Minnesota examines the evolutionary history of the mulberry family (Moraceae) using the DNA sequences from the living members of this ancient lineage of flowering plants. There are more than 1000 species of Moraceae worldwide, including such economically important fruits as figs, mulberries, jackfruit and breadfruit. Among the Moraceae, the figs (species of the genus Ficus) have been a major focus of research in ecology and evolution because of their complex interactions with fig wasps. Specialized wasps that feed on fig seeds are the exclusive pollinators of over 700 species of figs. The mutually beneficial relationship between figs and their wasps has stimulated much research on coevolution, the process by which two species undergo genetic change in response to each other. Ecological studies of fig pollination have advanced our understanding of coevolution, and yet the origins and evolutionary stages leading to fig pollination have remained virtually unknown. This project uses new tools of DNA sequencing and phylogenetic analysis to probe the early history of the mulberry family and to identify the closest relatives of the figs. Field work in the Old World tropics will focus on pollination biology of several Moraceae. Reconstructing patterns of diversification in this way makes it possible to test theories on the origin of the unique fig pollination syndrome, and to improve our understanding of general trends in floral evolution.The project will significantly expand our taxonomic and phylogenetic knowledge of an important branch of the tree of life. Economically significant members of the Moraceae include ornamental and edible figs (Ficus), breadfruit and jackfruit (Artocarpus), paperbark mulberry (Broussonetia), a source of fiber, and breadnut (Brosimum), a major tropical timber. Mulberry (Morus) also plays a key role in the production of silk as the main food source for silk moths. Understanding how these plants are related genetically is important for their sustainable use and conservation. In addition, the research provides an opportunity for advanced graduate training in state-of-the-art molecular techniques combined with museum collections-based approaches to the study of biodiversity.