Data from: Beech roots are simultaneously colonized by multiple genets of the ectomycorrhizal fungus Laccaria amethystina clustered in two genetic groups

In this study we characterize and compare the genetic structure of aboveground and belowground populations of the ectomycorrhizal fungus Laccaria amethystina in an unmanaged mixed beech forest. Fruiting bodies and mycorrhizas of L. amethystina were mapped and collected in four plots in the Świętokrzyskie Mountains (Poland). A total of 563 fruiting bodies and 394 mycorrhizas were successfully genotyped using the rDNA IGS1 (intergenic spacer) and seven SSR (simple sequence repeat) markers. We identified two different genetic clusters of L. amethystina in all of the plots, suggesting that a process of sympatric isolation may be occurring at a local scale. The proportion of individuals belonging to each cluster was similar among plots aboveground while it significantly differed belowground. Predominance of a given cluster could be explained by distinct host preferences or by priority effects and competition among genets. Both aboveground and belowground populations consisted of many intermingling small genets. Consequently, host trees were simultaneously colonized by many L. amethystina genets that may show different ecophysiological abilities. Our data showed that several genets may last for at least one year belowground and sustain into the next season. Ectomycorrhizal species reproducing by means of spores can form highly diverse and persistent belowground genets that may provide the host tree with higher resilience in a changing environment and enhance ecosystem performance.

本研究对未受人为干扰的山毛榉混交林中的外生菌根真菌（ectomycorrhizal fungus）紫晶蜡蘑（Laccaria amethystina）的地上与地下种群遗传结构进行表征与比较分析。研究团队在波兰圣十字山脉的4块样地中，对紫晶蜡蘑的子实体与菌根开展定位与采集工作。本研究共成功对563个子实体与394条菌根样本完成基因分型，采用的分子标记包括核糖体DNA基因间隔区1（rDNA IGS1，intergenic spacer）以及7个简单序列重复（SSR，simple sequence repeat）标记。所有样地中均检出两类不同的紫晶蜡蘑遗传聚类群，这提示局部尺度下可能存在同域隔离过程。地上种群中各聚类群的个体占比在各样地间无显著差异，而地下种群的占比则存在显著分化。某一聚类群的优势地位可通过宿主偏好差异、优先定植效应以及无性系间的竞争关系予以解释。地上与地下种群均由大量相互交织的小型无性系构成。因此，宿主树木可同时被多个具备不同生理生态特性的紫晶蜡蘑无性系定植。本研究数据显示，部分无性系可在地下存活至少一年并延续至下一生长季。通过孢子繁殖的外生菌根真菌可形成高度多样且持久的地下无性系群体，这能够提升宿主树木在环境变化中的抗逆能力，并改善生态系统整体功能。