Related Experiment Video
Updated: Jun 10, 2026

Asymbiotic Germination and Leaf Explant-Based Regeneration of the Endangered Medicinal Orchid Hemipilia cucullata from Mature Seeds
Published on: September 19, 2025
Mycoheterotrophy evolved from mixotrophic ancestors: evidence in Cymbidium (Orchidaceae)
Hiroyuki Motomura1, Marc-André Selosse, Florent Martos
1Tsukuba Botanical Garden, National Museum of Nature and Science, Tsukuba, Ibaraki, Japan.
Background And Aims:
Nutritional changes associated with the evolution of achlorophyllous, mycoheterotrophic plants have not previously been inferred with robust phylogenetic hypotheses. Variations in heterotrophy in accordance with the evolution of leaflessness were examined using a chlorophyllous-achlorophyllous species pair in Cymbidium (Orchidaceae), within a well studied phylogenetic background.
Methods:
To estimate the level of mycoheterotrophy in chlorophyllous and achlorophyllous Cymbidium, natural (13)C and (15)N contents (a proxy for the level of heterotrophy) were measured in four Cymbidium species and co-existing autotrophic and mycoheterotrophic plants and ectomycorrhizal fungi from two Japanese sites.
Key Results:
δ(13)C and δ(15)N values of the achlorophyllous C. macrorhizon and C. aberrans indicated that they are full mycoheterotrophs. δ(13)C and δ(15)N values of the chlorophyllous C. lancifolium and C. goeringii were intermediate between those of reference autotrophic and mycoheterotrophic plants; thus, they probably gain 30-50 % of their carbon resources from fungi. These data suggest that some chlorophyllous Cymbidium exhibit partial mycoheterotrophy (= mixotrophy).
Conclusions:
It is demonstrated for the first time that mycoheterotrophy evolved after the establishment of mixotrophy rather than through direct shifts from autotrophy to mycoheterotrophy. This may be one of the principal patterns in the evolution of mycoheterotrophy. The results also suggest that the establishment of symbiosis with ectomycorrhizal fungi in the lineage leading to mixotrophic Cymbidium served as pre-adaptation to the evolution of the mycoheterotrophic species. Similar processes of nutritional innovations probably occurred in several independent orchid groups, allowing niche expansion and radiation in Orchidaceae, probably the largest plant family.
More Related Videos
11:48Microscopy Techniques for Interpreting Fungal Colonization in Mycoheterotrophic Plants Tissues and Symbiotic Germination of Seeds
Published on: May 17, 2022
06:53Isolation, Characterization, and Total DNA Extraction to Identify Endophytic Fungi in Mycoheterotrophic Plants
Published on: May 5, 2023
Related Concept Videos
Fungal Group Zygomycota
Epiphytes, Parasites, and Carnivores
Eukaryotic Evolution
Contrary to the endosymbiont theory, the eukaryote-first hypothesis proposes that the simpler prokaryotic and...
Microbial Interactions: Mutualism
Bacterial Phylum Cyanobacteria
Diversity of Protists II