Serpentine soils do not limit mycorrhizal fungal diversity.
BACKGROUND
Physiologically stressful environments tend to host depauperate and specialized biological communities. Serpentine soils exemplify this phenomenon by imposing well-known constraints on plants; however, their effect on other organisms is still poorly understood.


RESULTS
We used a combination of field and molecular approaches to test the hypothesis that serpentine fungal communities are species-poor and specialized. We conducted surveys of ectomycorrhizal fungal diversity from adjacent serpentine and non-serpentine sites, described fungal communities using nrDNA Internal Transcribed Spacer (ITS) fragment and sequence analyses, and compared their phylogenetic community structure. Although we detected low fungal overlap across the two habitats, we found serpentine soils to support rich fungal communities that include representatives from all major fungal lineages. We failed to detect the phylogenetic signature of endemic clades that would result from specialization and adaptive radiation within this habitat.


CONCLUSIONS
Our results indicate that serpentine soils do not constitute an extreme environment for ectomycorrhizal fungi, and raise important questions about the role of symbioses in edaphic tolerance and the maintenance of biodiversity.
Branco
Sara
S
Committee on Evolutionary Biology, University of Chicago, Chicago, Illinois, United States of America. sbranco@uchicago.edu
Ree
Richard H
RH
D017632:Asbestos, Serpentine / Q000633:toxicity; D044822:Biodiversity; D021903:DNA, Ribosomal Spacer / Q000235:genetics; D038821:Mycorrhizae / Q000145:classification / Q000187:drug effects / Q000235:genetics* / Q000254:growth & development*; D010802:Phylogeny; D012988:Soil Microbiology
D017632:Asbestos, Serpentine; D021903:DNA, Ribosomal Spacer