Dissertation Research: Population Structure of the Late Stage Ectomycorrhizal Fungus, Russula brevipes

对于影响真菌与寄主树形成共生关系的遗传特征的历史和生殖因素的研究相对较少。为了阐明共生外生菌根真菌Russula brevipes的遗传结构，利用各种分子标记进行了研究，以确定历史和地理障碍（如冰川期和山脉的形成）如何影响传播、遗传组成和种群分化。在太平洋西北部和落基山脉地区的许多地点收集短叶蝉，以评估其遗传分化。外生菌根真菌（EMF）与树根形成不可或缺的共生关系，提供水和养分，提高幼苗存活率，并保护根系免受病原生物的侵害。在美国西部，短叶松与珍贵的木材和娱乐树木形成共生关系，包括黑松（Pinus contorta）、花旗松（Pseudotsuga menziesii）和锡特卡云杉（Picea sitchensis）。在落基山脉，黑松从未被重新种植到大面积的空地上，其再生依赖于电磁场介导的自然幼苗建立和存活过程。了解EMF的种群生物学和遗传结构非常重要，特别是因为这些真菌可能通过地下相互连接的网络介导物种之间的竞争，从而影响其宿主的生存能力。

MillerRelatively little research has been conducted on the historical and reproductive factors that affect genetic characteristics of fungi that form mutualistic associations with host trees. In an effort to elucidate the genetic structuring of the mutualistic ectomycorrhizal fungus, Russula brevipes, studies utilizing various molecular markers were designed to determine how historical and geographical barriers (e.g., ice ages and the formation of mountains) affect dispersal, genetic makeup and population differentiation. Collections of R. brevipes from many locations in the Pacific Northwest and Rocky Mountain region will be made to assess genetic differentiation.Ectomycorrhizal fungi (EMF) form indispensable symbiotic relationships with tree roots by providing water and nutrients, increasing seedling survivability, and protecting against root pathogenic organisms. R. brevipes forms mutualistic associations with valuable timber and recreation trees in the western U.S. including lodgepole pine (Pinus contorta), Douglas fir (Pseudotsuga menziesii) and Sitka spruce (Picea sitchensis). In the Rocky Mountains, lodgepole pine is never replanted into massive clearcuts and regeneration is dependent on processes of natural seedling establishment and survival mediated by EMF. It is important to understand the population biology and genetic structure of EMF, particularly since these fungi may affect survivability of their hosts by mediating competition between species through interconnected networks below-ground.