Collaborative Research: Orchid-Fungal Interactions-A System for Testing Hypotheses about the Ecological Role and Distribution of Mycorrhizal Fungi in Affecting Plant Distribution

所有陆生兰花都需要称为菌根的共生真菌，只有在这些真菌存在的情况下才能存活。它们与多种真菌相互作用——一些兰花是极端的专家，而另一些则是多面手，可以宿主许多不同的真菌。本研究以兰花-菌根结合为模型系统，探讨共生真菌和基质化学成分在调节兰花寄主植物分布和生长中的作用。为了确定共生真菌是否调节兰花的分布，提出了一系列实验室和野外实验，其中兰花种子，真菌伴侣，凋落物基质和非生物因素（光，水）被操纵。为了确定基质质量如何影响兰花生长，将在不同的基质、水和光制度下确定幼苗兰花的碳源。本研究将有助于了解兰花与菌根的相互作用以及不同胁迫（基质质量、光、水）条件下营养物质（碳）获取的性质。这项研究的结果将大大有利于保护工作。参与该项目的所有三个机构都将包括本科生参与研究，史密森学会（Smithsonian Institution）以少数族裔机构为重点的实习活动将用于吸引学生参与研究。

All terrestrial orchids require symbiotic fungi called mycorrhizae and can persist only when these fungi are present. They interact with a wide range of fungi - some orchids are extreme specialists, while others are generalists that can host many different fungi. The proposed study uses orchid-mycorrhizal associations as a model system to investigate the roles of symbiotic fungi and of the chemical composition of the substrate in regulating the distribution and growth of orchid host plants. To determine whether symbiotic fungi regulate the distribution of orchids, a series of laboratory and field experiments is proposed in which orchid seeds, fungal partners, litter substrates and abiotic factors (light, water) are manipulated. To determine how substrate quality affects orchid growth, carbon sources for seedling orchids will be determined under varying substrate, water and light regimes. This study will contribute fundamental knowledge about orchid-mycorrhizal interactions and about the nature of nutrient (carbon) acquisition under different stress (substrate quality, light, water) regimes. Results from this study research will substantially benefit conservation efforts. All three of the institutions involved in the project will include undergraduate students in research, and intern activities at the Smithsonian Institution that focus on minority institutions will be used to solicit student participation in the study.