Tri-kingdom co-evolution: mechanisms and consequences of hybridization

兰花为研究植物、昆虫和真菌类群的生态进化过程提供了一个特殊的研究系统，因为它们与杂交机制有关。兰花具有一系列独特的特征，包括：“漏洞百出”的物种界限混淆了流行的物种概念；各种授粉和受精综合症；以及完全依赖菌根萌发。虽然每个特征都可以在其他植物家族中找到，但兰花的所有特征的组合为更好地在微观和宏观进化尺度上解决生态和遗传物种形成机制的研究提供了一个机会。使用田间和基因组学方法，我使用沼泽兰(悬铃兰)系统来了解在生殖和生态成功的不同阶段，是什么驱动物种形成和杂交机制：授粉、受精、染色体进化和菌根专一性。这项工作将：1)开发一个基于兰花的系统，同时研究共同进化和物种形成过程中的多种因素及其复杂的相互作用；2)调查三界物种的相互作用及其生态相互依赖，以更好地了解潜在的生态和共同进化阈值；3)确定促进/阻碍进化过程的机制；4)揭示倍性和染色体结构的限制如何限制基因组兼容性和功能杂交；以及5)为学生提供跨多个分类群和学科的培训机会。我的研究项目翻译的知识在弱势群体管理、园艺繁殖、增加座果率、真菌生物安全和比较基因组学方面具有重要应用。

Orchids present an exceptional study system for investigating eco-evolutionary processes, as they relate to hybridization mechanisms, across plant, insect and fungal taxa. Orchids possess a combination of peculiar features including: `leaky' species boundaries that confound popular species concepts; a variety of pollination and fertilization syndromes; and a complete reliance on mycorrhiza for germination. While each feature can be found in other plant families, the combination of all features in orchids presents an opportunity to integrate studies that better address ecological and genetic speciation mechanisms at both micro- and macro-evolutionary scales. Using field and genomic methods, I use a bog orchid (Platanthera) system to understand what drives speciation and hybridization mechanisms at the various stages of reproductive and ecological success: pollination, fertilization, chromosomal evolution and mycorrhizal specificity. This work will: 1) develop an orchid-based system to simultaneously study multiple factors and their complex interactions on the process of co-evolution and speciation; 2) investigate tri-kingdom species interactions and their ecological co-dependencies to better understand potential ecological and co-evolutionary thresholds; 3) define mechanisms that facilitate/hinder evolutionary processes; 4) unravel how limitations of ploidy and chromosomal architecture can limit genomic compatibility and functional hybridization; and 5) provide opportunities for student training across multiple taxa and disciplines. Translated knowledge from my research program has important applications for the management of vulnerable populations, horticultural propagation, increasing fruit set, fungal biosecurity and comparative genomics.