Guilds of mycorrhizal fungi and their relation to trees, ericads, orchids and liverworts in a neotropical mountain rain forest
Guilds of mycorrhizal fungi and their relation to trees, ericads, orchids and liverworts in a neotropical mountain rain forest
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DOI：
10.1016/j.baae.2007.03.007
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发表时间：
2008-01-01
影响因子：
3.8
通讯作者：
Oberwinkler, Franz
中科院分区：
文献类型：
--
作者：
Kottke, Ingrid;Haug, Ingeborg;Oberwinkler, Franz
维管束植物的菌根和苔类和角藻的菌根状组合是陆地生态系统的组成部分，但在热带山地雨林中的研究很少。厄瓜多尔南部旧金山保留区的热带山地热带雨林区位于康苏埃洛科迪勒拉山脉的东坡，树种特别丰富，叶蝉和兰花非常丰富，但也有苔类植物。以前的光镜和电子显微镜研究表明，树根很好地被结构多样化的球孢菌门定植，附生的侧叶兰花与图拉斯奈菌目和担子菌门的菌根成员一起形成菌根。半附生冬虫夏草的菌根中也含有Sebacinales，天南星科的苔类植物中也含有Tulasnellales。在这些发现的基础上，我们假设寄主范围广泛的共生真菌在不同的植物物种和植物科之间建立了共享的公会甚至真菌网络。为了验证这一假说，利用球菌门小亚基rRNA(NucSSU)和担子菌门大亚单位rRNA(NucLSU)编码的核rDNA序列，对与根和菌体相关的真菌进行了分子系统发育研究。序列分析表明，Sebacinales和Tulasnellales仅在冬虫夏草和兰花之间共享，而不在冬虫夏草和兰花之间共享。然而，在丛枝菌根形成树方面，33个Glomus序列类型中有18个由不同科的2-4个树种共享。几乎所有被调查的树木都与另一树个体共享一种序列类型。担子菌门的寄主范围和潜在的共享行会似乎仅限于植物家族水平，但对于球孢菌门则涵盖了不同的植物家族。鉴于这里定义的序列类型对应于真菌物种，我们的发现表明树木之间可能存在真菌网络。(C)2007年Gesellschaft皮草Okologie。由Elsevier GmbH出版。版权所有。
Mycorrhizas of vascular plants and mycorrhiza-like associations of liverworts and hornworts are integral parts of terrestrial ecosystems, but have rarely been studied in tropical mountain rain forests. The tropical mountain rain forest area of the Reserva Biologica San Francisco in South Ecuador situated on the eastern slope of the Cordillera El Consuelo is exceptionally rich in tree species, ericads and orchids, but also in liverworts. Previous light and electron microscopical studies revealed that tree roots are well colonized by structurally diverse Glomeromycota, and that epiphytic, pleurothallid orchids form mycorrhizas with members of the Tulasnellales and the Sebacinales (Basidiomycota). Sebacinales also occurred in mycorrhizas of hemiepiphytic ericads and Tulasnellales were found in liverworts belonging to the Aneuraceae. On the basis of these findings, we hypothesized that symbiotic fungi with a broad host range created shared guilds or even fungal networks between different plant species and plant families. To test this hypothesis, molecular phylogenetic studies of the fungi associated with roots and thalli were carried out using sequences of the nuclear rDNA coding for the small subunit rRNA (nucSSU) of Glomeromycota and the large subunit rRNA (nucLSU) of Basidiomycota. Sequence analyses showed that Sebacinales and Tulasnellales were only shared within but not between ericads and orchids or between liverworts and orchids, respectively. Regarding arbuscular-mycorrhiza-forming trees, however, 18 out of 33 Glomus sequence types were shared by two to four tree species belonging to distinct families. Nearly all investigated trees shared one sequence type with another tree individual. Host range and potential shared guilds appeared to be restricted to the plant family level for Basidiomycota, but were covering diverse plant families in case of Glomeromycota. Given that the sequence types as defined here correspond to fungal species, our findings indicate potential fungal networks between trees. (C) 2007 Gesellschaft fur Okologie. Published by Elsevier GmbH. All rights reserved.