Molecular
Ecology 10(9): 2285 (Sept 2001)
Extreme specificity in epiparasitic Monotropoideae (Ericaceae):
widespread phylogenetic and geographical structure
M. I.
Bidartondo and T. D. Bruns
Abstract
The
Monotropoideae (Ericaceae) are nonphotosynthetic plants that obtain fixed
carbon from their fungal mycorrhizal associates. To infer the evolutionary
history of this symbiosis we identified both the plant and fungal lineages
involved using a molecular phylogenetic approach to screen 331 plants,
representing 10 of the 12 described species. For five species no prior
molecular data were available; for three species we confirmed prior studies
which used limited samples; for five species all previous reports are in
conflict with our results, which are supported by sequence analysis of multiple
samples and are consistent with the phylogenetic patterns of host plants. The
phylogenetic patterns observed indicate that: (i) each of the 13 plant
phylogenetic lineages identified is specialized to a different genus or species
group within five families of ectomycorrhizal Basidiomycetes; (ii) mycorrhizal
specificity is correlated with phylogeny; (iii) in sympatry, there is no
overlap in mature plant fungal symbionts even if the fungi and the plants are
closely related; and (iv) there are geographical patterns to specificity.