Dissertation Research: Fungal Community Effects on the Seed Bank of a Neotropical Tree

这项研究将研究巴拿马和哥斯达黎加两处低地森林中感染热带先锋树天蚕种子的真菌的群落组成、物种数量、空间结构和生态重要性。这项研究将（i）田间种子死亡率测量与（ii）分子分析相结合，以确定感染 C. insignis 种子的真菌的身份，以及（iii）重新接种健康种子以确定哪些真菌培养物具有致病性。这项研究的结果将首次评估真菌群落和重点真菌类群在影响热带森林常见树种人口统计方面的重要性，并将首次详细描述与任何温带或热带树木种子相关的真菌群落的特性和多样性。在两个研究最深入的热带森林中对单一寄主物种的种子-真菌相互作用进行比较，将增加有关大空间尺度土壤真菌多样性的重要新信息，并增强我们对真菌生物多样性的整体了解。分离株将存放在吉尔伯森真菌标本馆（亚利桑那大学），并保存在热带植物相关微真菌培养物保藏中心。新的基因序列数据将提交至在线数据库Genbank。

This research will examine the community composition, number of species, spatial structure and ecological importance of fungi infecting seeds of the tropical pioneer tree Cecropia insignis in two lowland forests in Panama and Costa Rica. This study will combine (i) measurements of seed mortality in the field with (ii) molecular analyses to determine the identities of fungi infecting C. insignis seeds, and (iii) re-inoculation of healthy seeds to determine which fungal cultures are pathogenic. Results of this study will provide the first assessment of the importance of fungal communities and focal fungal taxa in influencing demographics of a common tree species in tropical forests, and will provide the first detailed characterization of the identities and diversity of fungal communities associated with seeds of any tree, temperate or tropical. Comparisons of seed-fungal interactions of a single host species conducted at two of the best-studied tropical forests will add important new information regarding the diversity of fungi in soils at large spatial scales, and enhance our knowledge of fungal biodiversity overall. Isolates will be deposited in the Gilbertson Mycological Herbarium (University of Arizona), and maintained in a culture collection of tropical plant-associated microfungi. Novel genetic sequence data will be submitted to the on-line database Genbank.