Tedersoo Leho, Suvi Triin, Beaver Katy, Kõljalg Urmas
Institute of Botany and Ecology, University of Tartu. 40 Lai Street, 51005 Tartu, Estonia.
Plant Conservation Action Group. PO Box 392, Victoria, Mahé, the Seychelles.
New Phytol. 2007;175(2):321-333. doi: 10.1111/j.1469-8137.2007.02104.x.
Ectomycorrhizal (ECM) fungi form highly diverse communities in temperate forests, but little is known about their community ecology in tropical ecosystems. Using anatomotyping and rDNA sequencing, ECM fungi were identified on root tips of the introduced Eucalyptus robusta and Pinus caribea as well as the endemic Vateriopsis seychellarum and indigenous Intsia bijuga in the Seychelles. Sequencing revealed 30 species of ECM fungi on root tips of V. seychellarum and I. bijuga, with three species overlapping. Eucalyptus robusta shared five of these taxa, whereas P. caribea hosted three unique species of ECM fungi that were likely cointroduced with containerized seedlings. The thelephoroid (including the anamorphic genus Riessiella), euagaric, boletoid and hymenochaetoid clades of basidiomycetes dominated the ECM fungal community of native trees. Two species of Annulatascaceae (Sordariales, Ascomycota) were identified and described as ECM symbionts of V. seychellarum. The low diversity of native ECM fungi is attributed to deforestation and long-term isolation of the Seychelles. Native ECM fungi associate with exotic eucalypts, whereas cointroduced ECM fungi persist in pine plantations for decades.
外生菌根（ECM）真菌在温带森林中形成高度多样的群落，但对于它们在热带生态系统中的群落生态学却知之甚少。利用解剖分型和rDNA测序技术，在塞舌尔群岛引入的大叶桉和加勒比松以及当地特有的塞舌尔考氏榄仁树和土生土长的双柱苏枋的根尖上鉴定出了ECM真菌。测序结果显示，在塞舌尔考氏榄仁树和双柱苏枋的根尖上有30种ECM真菌，其中有3种重叠。大叶桉共有其中5个分类单元，而加勒比松有3种独特的ECM真菌，它们可能是随容器苗一同引入的。担子菌的革菌类（包括无性型的Riessiella属）、伞菌、牛肝菌类和层孔菌类分支主导了本地树木的ECM真菌群落。鉴定出了两种小环壳科（粪壳菌纲，子囊菌门）真菌，并将其描述为塞舌尔考氏榄仁树的ECM共生菌。本地ECM真菌的低多样性归因于塞舌尔群岛的森林砍伐和长期隔离。本地ECM真菌与外来桉树相关联，而一同引入的ECM真菌在松树林中持续存在了数十年。
