Record ID No. |
1980 |
Author(s) |
Otero J.T., Flanagan N.S., Herre E.A., Ackerman J.D., Bayman P , 2007 |
Affiliation |
University of Puerto Rico, Department of Biology, POB 23360, San Juan,PR 00931 USA |
Title |
Widespread mycorrhizal specificity correlates to mycorrhizal function in the neotropical, epiphytic orchid Ionopsis utricularioides (Orchidaceae) |
Source. Vol.(no):Page |
American Journal of Botany.94(12):1944-1950p. |
Categories |
Mycorrhiza General |
Subjects |
Biochemistry |
Sub-subjects |
Miscellaneous |
Organism |
n.a. |
Country |
United States |
Abstracts |
Tropical orchids constitute the greater part of orchid diversity, but little is
known about their obligate mycorrhizal relationships. The specificity of these interactions and
associated fungal distributions could influence orchid distributions and diversity. We
investigated the mycorrhizal specificity of the tropical epiphytic orchid Ionopsis
utricularioides across an extensive geographical range. DNA ITS sequence variation was surveyed
in both plants and mycorrhizal fungi. Phylogeographic relationships were estimated for the
mycorrhizal fungi. Orchid functional outcomes were determined through in vitro seed germination
and seedling growth with a broad phylogenetic representation of fungi. Most fungal isolates
derived from one clade of Ceratohasidium (anamorphs assignable to Ceratorhiza), with 78% within a
narrower phylogenetic group, clade B. No correlation was found between the distributions of
orchid and fungal genotypes. All fungal isolates significantly enhanced seed germination, while
fungi in clade B significantly enhanced seedling growth. These results show that I.
Utricularioides associates with a phylogenetically narrow, effective fungal clade over a broad
distribution. This preference for a widespread mycorrhizae may partly explain the ample
distribution and abundance of I. Utricularioides and contrasts with local mycorrhizal
diversification seen in some nonphotosynthetic orchids. Enhanced orchid function with a
particular fungal subclade suggests mycorrhizal specificity can increase orchid fitness. |