MtDNA and CpDNA Sequence Variation in Limber Pine and Ponderosa Pine

进化和保护生物学家用一种新技术、系统地理分析或系统地理研究物种内的地理变异。这项技术结合了对种群间遗传距离的估计和它们的地理位置，以更好地了解种群之间的历史关系。系统地理学研究通常用于动物研究，但很少用于植物研究。植物线粒体DNA的低突变率使系统地理学所需的序列变异最小化。这项研究是为了获得足够的线粒体和叶绿体DNA序列变异来进行樟子松和黄皮松的系统地理学研究。针叶树为系统地理学研究提供了一个令人兴奋的机会，因为它们的线粒体和叶绿体具有不同的遗传模式，因此它们的扩散潜力也截然不同。在松树中，母系遗传的mtDNA具有很低的扩散潜力，而父系遗传的cpDNA具有很高的扩散潜力。不同的基因流动潜力预计将产生截然不同的系统地理结构。线粒体系统地理学应该提供古代历史事件的指示，例如冰川避难所的隔离。叶绿体系统地理学应该提供对今天和最近过去种群间花粉流动的数量的洞察。

Mitton9983151Evolutionary and conservation biologists study the geographic variation within a species with a new technique, a phylogeographic analysis, or a phylogeography. This technique combines estimates of genetic distances among populations with their geographic positions to better understand the historical relationships among the populations. Phylogeographic studies are commonly used in studies of animals, but rarely in plants. The low mutation rate of plant mitochondrial DNA minimizes the sequence variation needed for a phylogeography. The proposed research is a survey for sufficient mitochondrial and chloroplast DNA sequence variation to conduct phylogeographies of limber pine and ponderosa pine.Conifers present an exciting opportunity for phylogeographic studies, for their mitochondria and chloroplasts have different patterns of inheritance and, consequently, drastically different potentials for dispersal. In the pines, the maternally inherited mtDNA has very low potential for dispersal, while the paternally inherited cpDNA has high potential for dispersal. The disparate potentials for gene flow are expected to produce dramatically different phylogeographies. The mitochondrial phylogeography should provide an indication of ancient historical events, such as isolation in glacial refugia. The chloroplast phylogeography should provide insights into the magnitude of pollen flow among populations today and in the recent past.