Cameron, DD; Preiß, K; Gebauer, G; Read, DJ: The chlorophyll-containing orchid Corallorhiza trifida derives little carbon through photosynthesis, New Phytologist, 183, 358-364 (2009), doi:10.1111/j.1469-8137.2009.02853.x | |
Abstract: While measurements of tissue stable isotope signatures and isotope mixing models have suggested that the green orchid Corallorhiza trifida is photosynthetically active and hence only partially mycoheterotrophic, these assumptions have not been validated by direct analysis of carbon assimilation. The photosynthetic capabilities of three orchid species assumed on the basis of the indirect methods or chlorophyll content to have differing trophic strategies: Neottia nidus-avis (fully mycoheterotrophic), Cephalanthera damasonium (partially autotrophic), C. trifida (partially autotrophic), as well as saplings of an autotrophic tree, Fagus sylvatica, were investigated by combining the determination of chlorophyll content and fluorescence, with direct measurement of the potential for CO2 assimilation using 13C isotope tracers in the field. Chlorophyll content and fluorescence values were indicative of ineffective photochemical processes in Neottia and reduced efficiency of photochemical processes in Corallorhiza. These differences are reflected in the mean assimilation rates of 13CO2 of 594 ± 129, 331 ± 72, 12.4 ± 2.4 and 7.3 ± 0.9 µg g−1 h−1 for Fagus, Cephalanthera, Corallorhiza and Neottia, respectively. Our study, while confirming the fully mycoheterotrophic status of Neottia and the partially autotrophic condition in Cephalanthera, also demonstrates under field conditions that Corallorhiza is physiologically closer to the fully mycoheterotrophic condition than has previously been recognized. |
BayCEER-Kolloquium: |
---|
Do. 18.04.2024 The Canvas of Change: Creative Marketing for Behaviour Change, Sustainability and Social Good |
Do. 18.04.2024 Survival, 'dormancy', and resuscitation of microorganisms in water-limited environments: insights from coastal salt flats and desert soil crusts |
BayCEER Short Courses: |
Di. 16.04.2024 Geographical information system and R environment for conservation biology |
Ökologisch-Botanischer Garten: |
So. 07.04.2024 Führung | Talking Tree: Was Bäume über´s Klima erzählen |
Fr. 19.04.2024 Führung | Gesteine im Ökologisch-Botanischen Garten |