Unraveling patterns of natural variation in an ecologically significant mutualism: species delimination and diversity in west coast mycorrhizal fungi

树木为了茁壮成长，必须与共生的菌根真菌联系在一起。气候变化模型预测，树种的范围在未来几年将发生巨大变化。他们的真菌伙伴能够跟上变化的步伐吗？我们的项目将通过提供Cortinarius、Inocybe和Russula的遗传多样性模式的系统框架来帮助回答这个问题，Cortinarius、Inocybe和Russula是加拿大西海岸分布最广、物种最丰富的三个真菌属。我们之前的环境采样突显了我们对这些真菌多样性的理解存在惊人的差距。大多数检测到的物种在真菌标本中没有代表性，它们的序列也没有在GenBank中出现。然而，如果以自然界的发生频率为指导的话，这些真菌是我们生态系统中的主要参与者。我们正在UBC植物馆/美丽博物馆建立真菌收藏，作为物种多样性信息的储存库，并为我们的研究提供材料。这要归功于本科生、当地专家和“业余”真菌学家的热情捐赠。通过这样的捐赠，我们在过去的一年里将UBC持有的Cortinarius标本增加了两倍。为了识别密切相关的标本组，我们使用标准真菌参照区：核糖体内转录间隔区(ITS)的DNA序列筛选UBC标本。对于有足够标本的物种(包括新捐赠的UBC标本、我的学生新收集的野外标本和其他草本植物的标本)，我们将使用额外的六个遗传基因座来划分物种。在仔细划分物种之后，我们将调查从卑诗省北部到俄勒冈州和华盛顿州的真菌种群细分和迁移率。低有效种群规模、狭窄的地理范围和有限的多样性可能标志着不太可能在气候变化中生存的物种。或者，大规模的有效种群规模和冰后快速迁徙的证据将提供一个令人鼓舞的迹象，表明个别真菌物种可能伴随着树种的迁徙，使这种重要的互惠共生得以保留。

Trees, in order to flourish, must be associated with symbiotic mycorrhizal fungi. Climate change models predict that ranges of tree species will change dramatically over the next years. Will their fungal partners be able to keep pace with the changes? Our project will help answer this question by providing a systematic framework of the patterns of genetic diversity in Cortinarius, Inocybe, and Russula, three of the most widespread and species rich fungal genera from Canada's west coast. Our previous environmental sampling highlighted astonishing gaps in our understanding of the diversity of these fungi. Most detected species were unrepresented in fungal collections and their sequences were absent from GenBank. Yet, if frequency of occurrence in nature is any guide, these same fungi are major players in our ecosystems. We are building the fungal collections in the UBC herbarium/Beaty museum to serve as a repository of information about species diversity and to provide the materials for our studies. This is possible thanks to enthusiastic donations from undergraduate students, local experts, and 'amateur' mycologists. Through such donations, we tripled UBC's holdings of Cortinarius specimens in the past year. So that we can recognize groups of closely related specimens, we are screening UBC specimens using DNA sequences from the standard fungal reference region: the ribosomal internal transcribed spacer (ITS). For species that are represented by enough specimens (after including newly donated UBC specimens, new field collections made by my students, and specimens from other herbaria) we will delimit species using six additional genetic loci. After careful delimitation of species, we will investigate fungal population subdivisions and migration rates from northern BC through Oregon and Washington. Low effective population sizes, narrow geographical ranges and limited diversity may flag species that are unlikely to survive climate change. Alternatively, large effective population sizes and evidence of rapid postglacial migration would provide an encouraging indication that individual fungal species are likely to accompany the migration of tree species, allowing the retention of this important mutualistic symbiosis.