DISSERTATION RESEARCH: The Genetic Basis of Local Adaptation: Serpentine Tolerance in Mimulus guttatus

自然景观往往是高度多变的，因此一个物种在其范围内可能会经历不同的选择压力。这种发散选择可以推动种群的适应性分化，保持遗传多样性，促进物种形成。种群对其当地栖息地的适应经常被证明，但在遗传层面上没有很好的特征。这项研究将着眼于对蛇纹石土壤的适应，以解决适应分歧的遗传基础。蛇纹土壤代表着一种特别恶劣的栖息地，大多数植物物种都不能在这种土壤中生存；然而，牙根分枝杆菌能够在这些土壤上和离开这些土壤生长。该项目将使用高通量DNA测序技术来识别导致对土壤条件耐受性差异的基因组区域，测试这些基因组区域在田间的适应意义，并识别能够在蛇纹岩土壤中生存的特征。确定适应异质环境的遗传基础的特征可以为预测种群如何应对不断变化的环境提供重要的见解。此外，通过确定在金属丰富、营养贫乏的土壤上涉及植物生长的基因组区域，该项目可能对受采矿或其他导致有毒土壤的活动影响的地点进行植物修复以及作物育种，以提高对贫瘠或有压力的土壤的耐受性。该项目将包括对高中生和本科生的指导以及公众的参与。

Natural landscapes are often highly variable such that a species is likely to experience different selective pressures across its range. Such divergent selection can drive the adaptive differentiation of populations, maintain genetic variation, and promote speciation. Adaptation of populations to their local habitat has frequently been demonstrated, but is not well characterized at the genetic level. This study will look at adaptation to serpentine soils in Mimulus guttatus (common monkeyflower) to address the genetic basis of adaptive divergence. Serpentine soils represent a particularly harsh habitat that most plant species cannot survive in; however, M. guttatus is able to grow both on and off of these soils. This project will use high-throughput DNA sequencing technology to identify regions of the genome that contribute to differences in tolerance to soil conditions, test the adaptive significance of these genomic regions in the field, and identify traits that enable survival on serpentine soils. Characterizing the genetic basis of adaptation to heterogeneous environments could provide important insights for predicting how populations may respond to changing environments. Furthermore, by identifying genomic regions involved in plant growth on metal enriched, nutrient poor soils this project could have implications for phytoremediation of sites affected by mining or other activities resulting in toxic soils as well as crop breeding to improve tolerance to poor or stressful soils. This project will include mentorship of high school and undergraduate students and the engagement of the general public.