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Inoculation potential of soil-borne Frankia on red alder (Alnus rubra Bong.)

Inoculation trials were set up in fumigated nursery beds for red alder (Alnus
rubra Bong.) seedling production. Frankia inoculum was applied in eight treatments:
control, nodule suspension, and three levels of cell suspension (strain ArI5) applied
with and without a peat carrier. Seedlings were evaluated at midseason and lifting.
The peat inoculum treatment produced larger seedlings than the other treatments, both
at mid-season and at lifting. The other treatments had little effect on growth. Size
differences paralleled differences in degree of nodulation. Differences in percentage
of seedlings nodulated were most pronounced at midseason, indicating that the
inoculation conferred primarily an early-season advantage.
In a second nursery experiment, Frankia inoculum was applied in a peat mix
carrier, in four treatments: uninoculated control, strain ArI5, strain AvcI1, and
combined dual-inoculum. Seedlings were evaluated at midseason and at lifting.
Frankia DNA from nodules was analyzed by DNA fingerprinting. The controls were
poorly nodulated and grew slowly. The single strain inoculum for ArI5 produced
larger seedlings than for AvcI1, both at mid-season and at lifting. The dual-inoculum
treatment produced larger seedlings than all other treatments. The AvcI1 single-inoculum
nodules primarily produced fingerprints identical to AvcI1, but nodule
fingerprints from all other treatments were dominated by ArI5 patterns.
In a field experiment, nodulation capacity was determined for soils from red
alder stands in the Oregon coast range covering a wide span of ages. Total nitrogen,
total carbon, nitrate, ammonium and pH were measured on the same soil samples.
Soil pH was most highly correlated with nodulation potential, with nitrate content also
significant. Cluster analysis of the sites using these two variables produced two
groups with distinctly different nodulation capacities. The higher capacity cluster was
lower in nitrate and higher in pH than the majority of sites in the lower capacity
cluster. There was general overlap in the age ranges for the two groups but the lower
capacity cluster contained the oldest sites. / Graduation date: 2002

Identiferoai:union.ndltd.org:ORGSU/oai:ir.library.oregonstate.edu:1957/32265
Date05 June 2001
CreatorsMartin, Kendall J.
ContributorsMyrold, David D.
Source SetsOregon State University
Languageen_US
Detected LanguageEnglish
TypeThesis/Dissertation

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