The mycorrhizal rootlets of Douglas-fir (Pseudotsuga menziesii (Mirb.) Franco.) and red alder (Alnus rubra Bong.) were extensively investigated. A jet-black mycorrhiza was found to be dominant on Douglas-fir rootlets. The fungal symbiont was identified as Cenococcum graniforme (Sow.) Ferd. and Winge. Two forms of mycorrhizae predominated on root systems of...
The influence of mycorrhizae on the nutrient uptake of
strawberries and red raspberries was investigated. On red raspberries
innoculation with a mycorrhizal fungus resulted in increased P uptake
and a greater concentration of P in the shoots of the plants. The
strawberries were innoculated with 2 species of mycorrhizal fungus....
A greenhouse bioassay was used to investigate effects of natural and manmade disturbances on native ectomycorrhizal populations of Douglas-fir and western hemlock on a steep southeast slope in the
west central Cascade Mountains. Total and mycorrhizal root tips were counted on seedlings grown in soils collected from (a) two 100+...
Results from approximately 400 fungus-host pure culture
inoculations indicate that specificity of ectomycorrhizal associations
is a complex phenomenon and cannot be based solely on field observations
of sporocarp-host associations. Of the numerous sporocarp-host
specific fungi tested, most formed ectomycorrhizae with one or more
unexpected, non-associated hosts. These results conclusively demonstrate...
Studies were conducted on inoculation of container-grown plants
with vesicular-arbuscular (VA) mycorrhizae.
Intraradical vesicles formed in colonized roots were found to
serve as propagules and significantly contribute to the infectivity
of these roots. A procedure was developed for separating
intraradical vesicles from roots; isolated intraradical vesicles were
able to colonize...
A study, consisting of two sequential greenhouse experiments, was
designed to determine the effects of soil liming upon the fungal
partner in a mycorrhizal association. A Willamette Valley foothill
soil, of the Jory series, was limed in increments to achieve a range
of acidity and alkalinity. The P-deficiency and P-fixing...
A study was conducted to characterize the vesicular-arbuscular
(VA) fungi of apples grown in Oregon. Using roots and soil from
apple orchards as inoculae, six different fungal species were found
in pot cultures: Gigaspora margarita Becker and Hall, Glomus fasciculatum
(Thaxter sensu Gerdemann) Gerd. and Trappe, Glomus mosseae
(Nicol. and...
Field and greenhouse bioassays were used to compare the mycorrhizal associations of Douglas-fir seedlings from undisturbed forests, and nonburned and burned portions of clearcuts on three Sites in the west-central Cascades of Oregon. Field soil transfers and greenhouse soil pasteurization and reinoculation were used to investigate soil biology and inoculum...
Published June 1983. Facts and recommendations in this publication may no longer be valid. Please look for up-to-date information in the OSU Extension Catalog: http://extension.oregonstate.edu/catalog
Basidiospores of Rhizopogon viriicolor Smith and R. colossus
Smith were inoculated onto container-grown Douglas-fir (Pseudotsuga
menziesii (Mirb.) Franco) seedlings and grown under two levels of
soluble fertilizer and one level of slow-release fertilizer. Both
fungi formed abundant (54%) ectomycorrhizae under the soluble
fertilizer regimes. Slow-release fertilizer greatly reduced percent
ectomycorrhizae...
The colonization of several species of plants by vesicularar-buscular
mycorrhizae (VAM) was studied to determine how host, soil,
or symbiont factors interacted to enhance growth of the host plant.
Seedlings of two species of the Cuppressaceae and two of the
Taxodiaceae formed VAM; colonization significantly improved growth.
This response to...
The influence of vesicular-arbuscular mycorrhizae (VAM) on
populations of general taxonomic and functional groups of naturally-occurring
rhizosphere bacteria and actinomycetes associated with
roots of sweet corn (Zea mays var. rugosa) and subterranean clover
(Trifolium subterraneum L.) was assayed using selective media.
Sporangial production by Phytophthora cinnamomi was also used as...
The several thousand fungi known to form ectomycorrhizae have co-evolved with their host plants and have developed impressive physiological and ecological diversity. Exploration of some relationships of enzyme activities and phytohormone production of selected ectomycorrhizal fungi to distribution and tree hosts is reported in this thesis. The data have particular...
Small-mammal community composition, microhabitat selection, and
dispersal of mycorrhizal fungal spores were studied in southwestern
Oregon. Sampled habitats exhibited structural variation resulting
from silvicultural practices.
In 1981, the effect of clearcut treatment on these phenomena was
evaluated. In 1982, the effect of forest structure was studied.
Discriminant function analysis (DFA)...
Many higher plants have mycorrhizae associated with their roots. These structures are often essential for survival and growth (Harley & Smith 1983). Mycorrhizae are known for the abilities to enhance nutrient absorption. While nitrogen-fixing organisms are found as components of the mycorrhizosphere, mycorrhizal fungi are not presently known to fix...