Rhizopogon salebrosus is a member of the order
Boletales, and the genus is the sister taxon to
Suillus. It is an ectomycorrhizal symbiont, and like
other fungi in this functional guild it is an important mutualist
that provides mineral nutrients to its host in exchange for
photosynthetically produced sugars. Pinus spp are its
primary hosts, and it is commonly found associated with them
throughout Western North America in both young and mature forest
settings.
Rhizopogon salebrosus is also host to the parasitic plant
Pterospora andromedea, which obtains carbon indirectly
from pine trees through the shared connection to R.
salebrosus. This epiparasitic plant is specifically associated
with Rhizopogon salebrosus and a few closely related
species. In fact the isolate used for the genomic sequence was
isolated from the roots of Pterospora andromedea.
The highly specific pattern of host specialization is typical of
epiparasitim interactions in the Monotropoidea, the subfamily that
contains Pterospora.
R. salebrosus produces an underground truffle-like
fruiting body that are dispersed through mycophagy by a diversity
of mammals including squirrels, voles, mice, marmots, deer, and
bears. The spores, once deposited in the soil, form long-lived
spore banks that colonize pine seedlings following disturbance and
serve an important role in forest regeneration.
