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

揭示具有生态意义的互利共生中的自然变异模式：西海岸菌根真菌的物种划分和多样性

• 批准号: 138427-2010
• 负责人: Berbee, Mary
• 金额: $ 1.82万
• 依托单位: University of British Columbia
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=451829
• 关键词: Unraveling; patterns; natural; variation; ecologically

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.

树木，为了繁荣，必须与共生菌根真菌。气候变化模型预测，未来几年树种的范围将发生巨大变化。它们的真菌伴侣能跟上变化的步伐吗？我们的项目将有助于回答这个问题，通过提供一个系统的框架，在Cortinarius，Inocybe和红菇，三个最广泛和物种丰富的真菌属从加拿大西海岸的遗传多样性的模式。我们之前的环境采样突出了我们对这些真菌多样性的理解的惊人差距。大多数检测到的物种在真菌标本中没有代表，它们的序列在GenBank中缺失。然而，如果自然界中出现的频率是任何指导，这些真菌是我们生态系统中的主要参与者。我们正在UBC植物标本馆/Beaty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。这是可能的，感谢来自本科生，当地专家和“业余”真菌学家的热情捐赠。通过这些捐赠，我们在过去一年中将UBC的Cortinarius标本数量增加了两倍。因此，我们可以识别组密切相关的标本，我们正在筛选UBC标本使用DNA序列从标准的真菌参考区域：核糖体内转录间隔区（ITS）。对于有足够标本代表的物种（包括新捐赠的UBC标本，我的学生新的野外收集标本，以及其他标本馆的标本），我们将使用六个额外的遗传位点来划分物种。经过仔细划定物种，我们将调查真菌种群细分和迁移率从北方公元前通过俄勒冈州和华盛顿。有效种群规模小、地理范围窄和多样性有限可能会使那些不太可能在气候变化中生存的物种处于不利地位。或者，大的有效人口规模和冰后期快速迁移的证据将提供一个令人鼓舞的迹象表明，个别真菌物种很可能伴随着树种的迁移，允许保留这种重要的互惠共生。