DISSERTATION RESEARCH: Reticulation and chromosomal evolution in Amaryllidaceae tribe Hippeastreae

本项目旨在研究新热带区开花植物中染色体多样性组的网状进化，Amaryllidaceae（孤挺花科）。 石蒜科朱顶红族（Amaryllidaceae tribe Hippeastelae）包括10-12属和约180种，包括石蒜、雨百合和其他植物，尽管这些植物在园艺上很重要，但其属的分类仍然存在争议。 这组单子叶植物是一个古老的杂交事件的后代，另外，最近的杂交混淆了进化关系。 主要目标是：1）评估海马网状进化的程度和性质; 2）探索系统发育背景下染色体进化的模式。 通过下一代测序技术获得的多个核基因的DNA序列，将研究该组的潜在进化历史或遗传学。 网状进化将通过考虑基因树异质性和网络表示的遗传学的方法来解决。 染色体进化将通过染色体数目变异的建模和细胞学特征（包括遗传、结构和数量差异）到进化树上的映射来评估。 该项目将通过整合分子方法提供植物进化中不同时间尺度和倍性水平（基因组复制）的网状结构的一般见解。这项研究将为共同研究者提供各种分子和细胞遗传学技术的重要培训机会，他将在他的祖国智利担任教师和研究员。 因此，他将为智利系统学研究项目的发展做出贡献，目前该领域缺乏足够的专业知识。 该项目将导致修订的Hippeastelae分类，这将有利于与这些植物合作的其他科学家和园艺家。 这一分类将被整合到eMonocot中，eMonocot是一个全球性的单子叶植物分类在线资源。

This project seeks to examine reticulate evolution in a chromosomally diverse group of Neotropical flowering plants, the Amaryllidaceae (amaryllis family). The generic classification of Amaryllidaceae tribe Hippeastreae, which includes 10-12 genera and ~180 species, including amaryllis, rain lilies, and other ornamentals, remains controversial, despite the horticultural importance of these plants. This group of monocots is putatively descended from an ancient hybridization event, and additional, more recent hybridizations have confounded evolutionary relationships. The main goals are to: 1) assess the extent and nature of reticulate evolution in Hippeastreae; and 2) explore patterns of chromosome evolution in a phylogenetic context. The underlying evolutionary history, or phylogeny, of the group will be investigated with DNA sequences of multiple nuclear genes obtained by next-generation sequencing techniques. Reticulate evolution will be addressed through methods that consider gene tree heterogeneity and network representations of the phylogeny. Chromosomal evolution will be assessed through modeling of chromosome number variation and mapping of cytological characters, including genetic, structural, and numerical differences, onto evolutionary trees. This project will provide general insights into reticulation in plant evolution at different temporal scales and ploidy levels (genome duplication) through an integrative molecular approach.This research will provide the co-PI with significant training opportunities in diverse molecular and cytogenetic techniques, which he will apply as a teacher and researcher in his home country, Chile. Hence, he will contribute to the development of systematics research programs in Chile, where this field currently lacks sufficient expertise. This project will result in a revised classification of Hippeastreae, which will benefit other scientists and horticulturists working with these plants. This classification will be integrated into eMonocot, a global online resource for monocot taxonomy.