Partial mycoheterotrophy in orchids
Funding: DFG Ge 565/7-2
From 05/2012 to 04/2016
Principal Investigator: Gerhard Gebauer
Staff: Julienne Schweiger
Partial mycoheterotrophy is now generally accepted in addition to initial mycoheterotrophy of all tiny orchid seedlings and full mycoheterotrophy of about 200 adult achlorophyllous orchids as an additional nutritional mode for a continuously increasing number of green forest orchid species. Characteristic of partially mycoheterotrophic orchids is their switch of the fungal partner towards mycorrhizae with ectomycorrhizal fungi of forest trees and the natural relative abundance of carbon (C) and nitrogen (N) stable isotopes in their tissues. Their stable isotope signature is positioned between fully autotrophic non-orchids living in the same micro-habitats and fully mycoheterotrophic orchids and varies in dependence on species, light climate and leaf chlorophyll concentration. Furthermore, they have unusually high total N concentrations in their tissues. Based on these findings of the 1st phase we will intensify in the 2nd phase of this project specifically studies (i) on relationships between local light climate and C exchange between fungi and orchids, (ii) on C and N isotope signatures in fully mycoheterotrophic seedlings of later on green orchid species, (iii) on identification of further partially mycoheterotrophic or non-mycoheterotrophic species including not conclusively clarified nutritional types and (iv) on the identification of the chemical nature of N compounds responsible for the unusually high total N concentrations in fully and partially mycoheterotrophic orchids.
Publications
| • Schweiger, JMI; Kemnade, C; Bidartondo, MI; Gebauer, G: Light limitation and partial mycoheterotrophy in rhizoctonia-associated orchids, Oecologia, 189, 375-383 (2019), doi:10.1007/s00442-019-04340-0 |
| • Schiebold, JMI; Bidartondo, MI; Lenhard, F; Makiola, A; Gebauer, G: Exploiting mycorrhizas in broad daylight: Partial mycoheterotrophy is a common nutritional strategy in meadow orchids, Journal of Ecology, 106, 168-178 (2018), doi:10.1111/1365-2745.12831 |
| • Schweiger, JMI; Bidartondo, MI; Gebauer, G: Stable isotope signatures of underground seedlings reveal the organic matter gained by adult orchids from mycorrhizal fungi, Functional Ecology, 32, 870-881 (2018), doi:10.1111/1365-2435.13042 |
| • Schiebold, JMI; Bidartondo, MI; Karasch, P; Gravendeel, B; Gebauer, G: You are what you get from your fungi: nitrogen stable isotope patterns in Epipactis species., Annals of Botany, 119, 1085-1095 (2017), doi:10.1093/aob/mcw265 |
| • Hynson, NA; Schiebold, JMI; Gebauer, G: Plant family identity distinguishes patterns of carbon and nitrogen stable isotope abundance and nitrogen concentration in mycoheterotrophic plants associated with ectomycorrhizal fungi., Annals of Botany, 118, 467-479 (2016), doi:10.1093/aob/mcw119 |
| • Ercole, E; Adamo, M; Rodda, M; Gebauer, G; Girlanda, M; Perotto, S: Temporal variation in mycorrhizal diversity and C and N stable isotope abundance in the winter-green meadow orchid Anacamptis morio, New Phytologist, 205, 1308-1319 (2015), doi:10.1111/nph.13109 |
| • Lee, Y-I; Yang, C-K; Gebauer, G: The importance of associations with saprotrophic non-Rhizoctonia fungi among fully mycoheterotrophic orchids is currently under-estimated: novel evidence from sub-tropical Asia, Annals of Botany, 116, 423-435 (2015), doi:10.1093/aob/mcv085 |
| • Liebel, HT; Bidartondo, MI; Gebauer, G: Are carbon and nitrogen exchange between fungi and the orchid Goodyera repens affected by irradiance?, Annals of Botany, 115, 251-261 (2015), doi:10.1093/aob/mcu240 |