Phylogenetic relationships and reticulate evolution in Poa and subtribe Poinae

我的研究计划的长期目标集中在了解系统发育关系和杂交对开花植物进化的影响。 我的研究主要集中在大型草族Poeae和最大的草属Poa，通常被称为蓝草，作为这些研究的模型。 早熟禾属是开花植物中最具分类学挑战性的属之一;其复杂性被认为是由于广泛的杂交和多倍性，进一步由形态减少和缺乏有用的特征进行鉴定。 我们以前的研究成功地利用分子数据构建了早熟禾属内和相关属间进化关系的框架。 使用这种系统发育假说，沿着仔细考虑形态特征，我们最近提出了一个初步的广泛修订的分类方案早熟禾，第一个与世界范围内的属。 我们通过鉴定古老和相对较近的杂交案例，在Poa内及其与其他属之间，在解开其复杂的相互交织的谱系历史方面取得了进展。 我现在建议通过对额外的DNA区域进行采样并扩大地理和分类覆盖范围来测试我们的系统发育假设和分类的鲁棒性。 多个分类水平将被检查，从speciose组内早熟禾部落水平，杂交的情况下，将被确定和详细探讨。 我们的目标是最终了解这一生态上成功的、物种丰富的植物群的进化历史、多样化、植物地理学、形态学和育种系统进化，为世界范围的修订提供一个健全的系统发育框架，并进一步了解开花植物的网状进化和杂交起源。和覆盖作物，所获得的信息也可以在应用程序，如农学，土地开垦和保护管理有用。

The long-term objectives of my research program focus on understanding phylogenetic relationships and the influence of hybridization on the evolution in flowering plants. My research is focused primarily on the large grass tribe Poeae and the largest grass genus Poa, commonly known as bluegrass, as the model for these studies. Poa is one of the most taxonomically challenging genera of flowering plants; its complexity is thought to be due to extensive hybridization and polyploidy, further compounded by morphological reduction and the paucity of useful characters for identification. Our previous research successfully used molecular data to construct a framework of evolutionary relationships within Poa and among related genera. Using this phylogenetic hypothesis, along with a careful consideration of morphological characters, we recently presented a preliminary extensively revised classification scheme for Poa, the first with world-wide coverage for the genus. We made progress towards unraveling its complex history of intertwined lineages by identifying cases of ancient and relatively recent hybridization, both within Poa and between it and other genera. I now propose to test the robustness of our phylogenetic hypothesis and classification by sampling additional DNA regions and broadening the geographic and taxonomic coverage. Multiple taxonomic levels will be examined, from speciose groups within Poa up to the tribe level, and cases of hybridization will be identified and explored in detail. Our aims are ultimately to understand the evolutionary history, diversification, biogeography, morphological and breeding system evolution in this ecologically successful, species-rich group of plants, to provide a sound phylogenetic framework for worldwide revisions, and to further our understanding of reticulate evolution and hybrid origin in flowering plants Economically important as nutritious and palatable forage, lawn and pasture grass, soil stabilizers, and cover crops, information gained can also be useful in applied applications such as agronomy, land reclamation, and conservation management.