Collaborative Research: The Roles of Polyploidy and Apomixis in Shaping the Diversity and Distribution of Cheilanthoid Ferns

多倍体（细胞核内染色体组的增殖）和无融合生殖（不受精就产生胚胎）在许多生物体中都有发现。它们在杂种繁殖中的作用（在小麦、棉花、柑橘等中）有很好的文献记载，但它们对遗传多样性和地理分布的影响在很大程度上尚未探索。多倍体和无融合生殖在唇齿蕨中特别普遍，唇齿蕨是一组500多个物种，适应大多数其他蕨类植物避免的季节性干燥栖息地，它们显然有助于这些物种在这些气候挑战的环境中繁荣的能力。利用遗传（DNA，蛋白质和染色体）和形态分析的组合，该项目将探讨多倍体和无融合生殖，遗传多样性和殖民边缘栖息地的能力之间的这种明显的联系。本研究将探讨多倍体和无融合生殖如何有助于旱生适应植物的进化成功，促进适用于一般陆地植物的假说的发展。面对全球气候变化和日益严重的干旱，这些研究可能至关重要。其他目标包括开发在线识别指南，创建供高中教师使用的教学模块，系统学本科生和研究生培训，以及向实地工作所在国的学生和专业人员进行宣传。

Polyploidy (the multiplication of chromosome sets within a nucleus) and apomixis (the production of embryos without fertilization) are encountered in many living organisms. Their roles in the propagation of hybrids (in wheat, cotton, citrus, etc.) are well documented, but their effects on genetic diversity and geographic distribution are largely unexplored. Polyploidy and apomixis are especially prevalent in cheilanthoid ferns, a group of 500+ species adapted to seasonally dry habitats avoided by most other ferns, and they clearly have contributed to the ability of these species to prosper in these climatically-challenged environments. Using a combination of genetic (DNA, protein, and chromosome) and morphological analyses, this project will explore this apparent connection between polyploidy and apomixis, genetic diversity, and the ability to colonize marginal habitats. This study will examine how polyploidy and apomixis have contributed to the evolutionary success of xeric-adapted plants, facilitating the development of hypotheses applicable to land plants in general. Such studies may prove critical in the face of global climate change and increasing aridity. Additional goals include development of an online identification guide, creation of teaching modules for use by high school teachers, graduate and postgraduate training in systematics, and outreach to students and professionals in countries hosting field work.