Colonization patterns of mycorrhizal fungi associated with two rare orchids, Cephalanthera falcata and C. erecta

• Published in: Ecological research Vol. 24; no. 5; pp. 1023 - 1031
• Main Authors: Matsuda, Yosuke, Amiya, Aya, Ito, Shin-ichiro
• Format: Journal Article
• Language: English
• Published: Japan Springer Japan 01.09.2009; Blackwell Publishing Ltd
• Subjects: Behavioral Sciences; Biomedical and Life Sciences; Cephalanthera; Colonization; Ecology; Evolutionary Biology; Flowers & plants; Forestry; Forests; Fungi; Life Sciences; Orchid mycorrhizas; Orchidaceae; Original Article; Peloton formation; Plant populations; Plant Sciences; Plant species; Risk management; Root system; Roots; Sebacinaceae; Soil microorganisms; Spatial distribution; Taxonomy; Thelephoraceae; Threatened species; Zoology; Thelephoraceae; Sebacinaceae; Orchid mycorrhizas; Peloton formation; Root system
• ISSN: 0912-3814; 1440-1703
• DOI: 10.1007/s11284-008-0575-0

We investigated the spatial distribution and taxonomic identity of mycorrhizal fungi colonizing the root systems of two threatened Cephalanthera species, C. falcata and C. erecta , in naturally regenerated forests. Peloton formation was observed in both plant species, confirming the existence of orchid mycorrhizas. For C. falcata , mycorrhization was significantly different among individuals, ranging from 14 to 63%, and no significant difference among C. erecta individuals was detected (57–68%). Mycorrhization among three growth directions of roots and between orchid species was not significantly different. The spatial distribution of mycorrhizas in both orchids showed significant differences, being most frequent at an apical position. Based on DNA sequencing and phylogenetic analyses, we inferred that the families Thelephoraceae and Sebacinaceae were mycobionts for C. falcata and Thelephoraceae for C. erecta . Our findings indicated that mycorrhizal colonization occurs at a distal position from the base of these orchid root systems and that mycorrhizal fungi are restricted to few ectomycorrhizal fungal families.