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

兰花为研究植物、昆虫和真菌分类群的杂交机制提供了一个特殊的生态进化过程研究系统。兰花具有一系列奇特的特征，包括：泄漏的物种边界，混淆了流行的物种概念；各种授粉和受精综合征；并且完全依赖菌根发芽。虽然每种特征都可以在其他植物科中找到，但兰花中所有特征的结合为整合研究提供了机会，从而更好地解决微观和宏观进化尺度上的生态和遗传物种形成机制。使用田间和基因组方法，我使用沼泽兰（Platanthera）系统来了解在生殖和生态成功的各个阶段驱动物种形成和杂交机制的因素：授粉，受精，染色体进化和菌根特异性。本研究将：1)建立一个以兰科植物为基础的系统，同时研究兰科植物共同进化和物种形成过程中的多因素及其复杂相互作用；2)研究三界物种的相互作用及其生态相互依赖关系，以更好地了解潜在的生态和共同进化阈值；3)定义促进/阻碍进化过程的机制；4)揭示倍性和染色体结构的局限性如何限制基因组相容性和功能性杂交；5)为学生提供跨分类群和学科的培训机会。我的研究项目转化的知识在脆弱群体的管理、园艺繁殖、增加坐果、真菌生物安全和比较基因组学方面具有重要的应用。

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.