Temporal variation in mycorrhizal diversity and carbon and nitrogen stable isotope abundance in the wintergreen meadow orchid Anacamptis morio

• Published in: The New phytologist Vol. 205; no. 3; pp. 1308 - 1319
• Main Authors: Ercole, Enrico, Adamo, Martino, Rodda, Michele, Gebauer, Gerhard, Girlanda, Mariangela, Perotto, Silvia
• Format: Journal Article
• Language: English
• Published: England Academic Press 01.02.2015; New Phytologist Trust; Wiley Subscription Services, Inc
• Subjects: Abundance; adults; Anacamptis morio; Ascomycetes; Autotrophic Processes; Autumn; Bayes Theorem; Biodiversity; Carbon; Carbon Isotopes; Ceratobasidium; Depletion; Environmental conditions; environmental factors; fungal communities; fungal diversity; Fungi; Grassland; Growing season; Isotopes; mature plants; Meadows; mixotrophy; Molecular Sequence Data; multivariate analysis; mycorrhizae; Mycorrhizae - physiology; Mycorrhizal fungi; mycorrhizal temporal variation; Mycorrhizas; Nitrogen; Nitrogen Isotopes; orchid mycorrhiza; Orchidaceae; Orchidaceae - microbiology; Pezizaceae; Phylogenetics; Phylogeny; Plant ecology; Plant growth; Plant Leaves - metabolism; Plant roots; Plants; seasonal variation; Species; spring; stable isotope dynamics; Stable isotopes; summer; Symbiosis; Tansley reviews; Temporal variations; Time Factors; Tulasnella; winter; stable isotope dynamics; fungal diversity; orchid mycorrhiza; mycorrhizal temporal variation; mixotrophy; Anacamptis morio
• ISSN: 0028-646X; 1469-8137; 1469-8137
• DOI: 10.1111/nph.13109

Many adult orchids, especially photoautotrophic species, associate with a diverse range of mycorrhizal fungi, but little is known about the temporal changes that might occur in the diversity and functioning of orchid mycorrhiza during vegetative and reproductive plant growth. Temporal variations in the spectrum of mycorrhizal fungi and in stable isotope natural abundance were investigated in adult plants of Anacamptis morio, a wintergreen meadow orchid. Anacamptis morio associated with mycorrhizal fungi belonging to Tulasnella, Ceratobasidium and a clade of Pezizaceae (Ascomycetes). When a complete growing season was investigated, multivariate analyses indicated significant differences in the mycorrhizal fungal community. Among fungi identified from manually isolated pelotons, Tulasnella was more common in autumn and winter, the pezizacean clade was very frequent in spring, and Ceratobasidium was more frequent in summer. By contrast, relatively small variations were found in carbon (C) and nitrogen (N) stable isotope natural abundance, A. morio samples showing similar¹⁵N enrichment and¹³C depletion at the different sampling times. These observations suggest that, irrespective of differences in the seasonal environmental conditions, the plant phenological stages and the associated fungi, the isotopic content in mycorrhizal A. morio remains fairly constant over time.