Dissertation Research: Dispersal, Breeding Patterns, and Genetic Structure of an Epiphytic Orchid

Hamrick0104598在植物中，基因运动通过花粉或种子进行。在大多数开花植物中，花粉可能比种子传播的距离更远。然而，兰花能够进行相当长距离的种子传播，而花粉的流动仅限于传粉者的活动范围。花粉和种子传播对遗传变异总体划分的相对贡献是什么？在受干扰的栖息地中发生了多少基因运动？这种运动的空间尺度是多少？为了解决这些问题，将利用双亲遗传的核标记(等位酶)和母本遗传的叶绿体序列标记，在多个空间尺度上研究新热带附生兰花冬凌草的遗传多样性分布。遗传多样性对物种的长期生存至关重要，特别是在日益无处不在的支离破碎和受干扰的地貌中。它增加了一个物种能够在环境波动和自然灾害中幸存下来的可能性，这些变化和自然灾害总是随着时间的推移而发生。通过更好地了解花粉和种子传播如何影响这种兰花的遗传多样性分布，将深入了解森林碎片化如何影响遗传生存能力，以及具有远距离种子传播能力的物种如何保存遗传变异，从而促进它们在高度干扰的生境中长期生存。

Hamrick0104598In plants, gene movement is mediated either via pollen or seeds. In most flowering plants, pollen can potentially travel much greater distances than seeds. Orchids, however, are capable of considerable long-distance seed dispersal while pollen flow is limited to the range of pollinator movement. What is the relative contribution of pollen and seed dispersal to overall partitioning of genetic variation? How much gene movement occurs in disturbed habitats and what is the spatial scale of that movement? To address these questions, the distribution of genetic diversity in the neotropical, epiphytic orchid, Laelia rubescens, will be examined at multiple spatial scales using biparentally inherited nuclear markers (allozymes) and maternally inherited chloroplast sequence markers. Genetic diversity is crucial for the long-tern survival of species, particularly in fragmented and disturbed landscapes which are becoming increasingly ubiquitous. It increases the likelihood that a species can survive environmental fluctuations and natural catastrophes that invariably occur over time. By better understanding how pollen and seed dispersal impact the distribution of genetic diversity in this orchid, insights will be gained into how forest fragmentation influences genetic viability and how species with long-distance seed dispersal capabilities may preserve genetic variation and thereby facilitate their long-term survival in highly disturbed habitats.