Many mycorrhizosphere microorganisms can produce
plant growth regulating compounds in vitro. Plant growth
regulating compounds are known to mediate root growth and
development. In reforestation practices, conifer tree
seedling growth and survival are linked to rapid root
growth and development after outplanting. Multifactorial
experiments were conducted to document variations in...
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 ectomycorrhizal fungi Cenococcum geophilum, Hebeloma
crustuliniforme and Laccaria laccata produced ethylene in vitro in
modified Melin-Norkrans liquid medium only if amended with 2.5 to
10 mM methionine; Pisolithus tinctorius failed to produce ethylene
unless the cultures were renewed with fresh methionine-amended
medium prior to ethylene assay. An additional 19...
Fusarium spp. frequent conifer nursery soils yet are rarely recovered from coniferous forest soils. Experiments were performed to determine what influence humic-rich organic amendments and volatiles from soil, ectomycorrhizal fungi and ectomycorrhizae have on the populations of several physiologic and taxonomic microbial groups potentially related to this phenomenon. A comparative...
Fusarium spp. are among the most important pathogens of Douglas-fir
(Pseudotsuga menziesii) seedlings in bareroot nurseries. Currently the most effective
disease control method is soil fumigation with methyl bromide. As methyl bromide is
phased out, however, other disease management strategies may become more important.
We explored two alternative approaches 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...