6 Wood Discoloration

80 3 Physiology
tree fungi (“biological forest protection”) and against fungi on wood in service
(“biological wood protection”) (Wälchli 1982; Bruce 1992; Holdenrieder and
Greig 1998; Phillips-Laing et al. 2003).
As early as 1934, Weindling showed the inhibiting effect of Trichoderma
species on several fungi. Bjerkandera adusta and Ganoderma species were
antagonistic against the causing agent of Plane canker stain disease (Grosclaude
et al. 1990). Also, v. Aufseß (1976) examined mycelial interactions between
Heterobasidion annosum and Stereum sanguinolentum and antagonistic fungi
like Phlebiopsis gigantea and Trichoderma viride (also Holdenrieder 1984).
Root rot by Heterobasidion annosum (Chap. 8.3.2) is the classical target for
biological forest protection and the only example of a successful biological
control of a fungal forest disease. Based on the work of Rishbeth, stump treatment
with Phlebiopsis gigantea was developed and successfully used in several
countries. Originally in England, the spread of root rot in pine sites was diminished
by the immediate coating of the fresh stump surface with an aqueous
spore (asexual arthrospores) suspension of P. gigantea (Meredith 1959; Rishbeth
1963). The antagonist colonizes the stump, that is H. annosum cannot
infect it by air-borne spores and thus an infection of neighboring trees via
root grafts is prevented. The treatment of spruces yielded differently satisfactory
results (Korhonen et al. 1994; Holdenrieder et al. 1997). Holdenrieder and
Greig (1998) listed also several bacteria, which were antagonistic against H. annosum.
Promising systems for the biological protection of growing trees have
been studied against Armillaria luteobubalina, Chondrostereum purpureum,
Phellinus tremulae, P. weirii, and Ophiostoma ulmi (Bruce 1998; also Palli and
Retnakaran 1998).
There were many attempts for biological wood protection (Bruce 1998).
To date, the application of biological control to prevent wood decay and discoloration
has been successful in the laboratory, but was often inconsistent
in its performance in the field (Dawson-Andoh and Morrell 1997; Mikluscak
and Dawson-Andoh 2004b). Much work has been done in the Forest Products
Laboratory, Madison. In the laboratory, a blue stain fungus was inhibited by
antibiotic substances from Coniophora puteana (Croan and Highley 1990) and
Bjerkandera adusta (Croan and Highley 1993). Bacteria were examined for
their suitability to prevent of blue stain (Bernier et al. 1986; Seifert et al. 1987;
Benko 1989; Florence and Sharma 1990; Kreber and Morrell 1993; Bjurman
et al. 1998; Payne et al. 2000; Bruce et al. 2004). A bacterial mixed culture decreased
staining and molding of pine wood samples as well as decay by Trametes
versicolor and Oligoporus placenta (Benko and Highley 1990). Streptomyces rimosus
Sobin, Finlay & Kane (Croan and Highley 1992b) and its culture filtrate
(Croan and Highley 1992c) prevented spore germination of Aspergillus niger,
Penicillium sp. and Trichoderma sp.aswellasbluestainbyAureobasidium
pullulans. Trichoderma species are extensively researched biological control
agents for wood protection against decay fungi (Highley and Ricard 1988;
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