Coevolution between algae and fungi in lichen associations

地衣群落中藻类和真菌之间的共同进化地衣是研究最少的生物之一，也是对环境变化最敏感的生物之一，对组成地衣群落的藻类和真菌共生体之间的共同进化共生伙伴关系知之甚少。广泛分布的枝状地衣属包括在稳定环境中生长的物种(驯鹿地衣；枝状枝状地衣及相关物种)和生长在不稳定干扰环境中的物种(精灵杯状地衣；拟枝状枝状地衣及同类)。这项研究的目的是研究生长在不同栖息地的两组物种(驯鹿和仙人杯地衣)的每个藻类和真菌基因组以及共生体之间的遗传变异模式，以确定：1)物种和种群之间的进化关系，2)繁殖模式和交配系统，3)每个共生体的种群结构。这些目标将使用每个藻类和真菌伙伴的核和线粒体标记进行检查。这项研究将阐明地理和分类尺度在共同进化研究中的重要性，种群水平的活动可能决定更高分类水平的共同进化关系，以及先锋地衣和顶端地衣之间的适应机制可能存在重要差异。这些研究还将有助于理解稀有和濒危物种或入侵和广泛分布的物种的适应情况。这些信息对于实施以科学为基础的自然资源管理战略很重要。

Summary of proposed research Coevolution between algae and fungi in lichen associations Lichens are among the most understudied organisms and the most sensitive to environmental changes with little known about the co-evolving symbiotic partnership between algal and fungal symbionts that make up lichen associations. The widespread genus Cladonia contains species that grow in stable environments (Reindeer lichens; Cladonia rangiferina and allies) and species that grow in unstable disturbed sites (Pixie cup lichens; Cladonia pyxidata and allies). The objectives of this research are to examine patterns of genetic variation in each of the algal and fungal genomes and between symbionts for two groups of species that grow in different habitats (reindeer and pixie cup lichens) to determine: 1) evolutionary relationships among species and populations, 2) mode of reproduction and mating system, and 3) population structure for each of the symbionts. These objectives will be examined using nuclear and mitochondrial markers for each of the algal and fungal partners. This research will illustrate the importance of geographic and taxonomic scale in coevolutionary studies, that population level activity may determine coevolutionary relationships at higher taxonomic levels, and that there may be important differences in the mechanisms of adaptation between pioneer and climax lichens. These studies will also shed light on the understanding of adaptation in rare and endangered species or invasive and widespread species. This information is important for implementing science-based management strategies of natural resources.