Differences in mycorrhizal preferences between two tropical orchids
- 16 June 2004
- journal article
- research article
- Published by Wiley in Molecular Ecology
- Vol. 13 (8), 2393-2404
- https://doi.org/10.1111/j.1365-294x.2004.02223.x
Abstract
Orchids parasitize their mycorrhizal fungi and are dependent on them for seed germination. Controversy reigns over how specific the mycorrhizal association is in tropical species. Although there is little experimental evidence to support any viewpoint, some variation is known to exist. We compared mycorrhizal specificity and performance in two phylogenetically related epiphytic orchids from Puerto Rico, Tolumnia variegata and Ionopsis utricularioides (Oncidiinae) by integrating two techniques: phylogenetic analysis of mycorrhizal fungi based on nuclear ribosomal internal transcribed spacer (ITS) sequences, and symbiotic seed germination experiments. Most of the mycorrhizal isolates from T. variegata fell into four different clades of Ceratobasidium, while most of those from I. utricularioides were restricted to a single clade of the same genus. Seeds of T. variegata germinated equally well with fungi from both T. variegata and I. utricularioides, but seeds of I. utricularioides germinated significantly better with its own isolates. Seeds of I. utricularioides germinated and developed faster than those of T. variegata. Both the molecular phylogeny and the seed germination experiments showed that T. variegata is a generalist in its association with fungal symbionts. In contrast, I. utricularioides is more specialized and more effective at exploiting a specific fungal clade. Our data are consistent with the theoretical trade-offs between specialized and generalized interactions.Keywords
This publication has 70 references indexed in Scilit:
- An expanded plastid DNA phylogeny of Orchidaceae and analysis of jackknife branch support strategyAmerican Journal of Botany, 2004
- Diversity and host specificity of endophytic Rhizoctonia‐like fungi from tropical orchidsAmerican Journal of Botany, 2002
- Phylogenetic Placement and Host Specificity of Mycorrhizal Isolates Belonging to AG-6 and AG-12 in the Rhizoctonia solani Species ComplexMycologia, 2001
- What makes a specialist special?Trends in Ecology & Evolution, 1999
- An Orchid Flora of Puerto Rico and the Virgin IslandsKew Bulletin, 1996
- CLUSTAL W: improving the sensitivity of progressive multiple sequence alignment through sequence weighting, position-specific gap penalties and weight matrix choiceNucleic Acids Research, 1994
- Factors Associated with a Rust Infection (Sphenosphora saphena) in an Epiphytic Orchid (Tolumnia variegata)American Journal of Botany, 1994
- Diversity and Seasonality of Male Euglossine Bees (Hymenoptera: Apidae) in Central PanamÁEcology, 1983
- Perfect states of some rhizoctoniasTransactions of the British Mycological Society, 1966