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Successive collections of Basidiospores from wood decay fungi (in vitro) show variation in germination levels on common media
1978 - IRG/WP 191
In the course of various preliminary experiments in which spore germination levels of 6 decay fungi on malt and water agar were recorded as controls, it was noted that one could not reliably obtain an expected level of spore germination for any particular fungus. Inconsistent 'control' spore germination levels of a fungus greatly complicates large scale experiments in which comparisons of data based on germination levels are attempted upon replication of the study over time. This study was done to determine if, in fact, spores collected at different times from specific hymenial areas of wood decay fungi sporulating in vitro differed significantly in germination level on common media under standardized conditions.
E L Schmidt, D W French

Synergistic effect of boron on Streptomyces rimosus metabolites in preventing conidial germination of sapstain and mold fungi
1992 - IRG/WP 92-1565
We evaluated the synergistic effect of boron (4% BAE solution of Tim-Bor or 4% boric acid) on Streptomyces rimosus metabolites in preventing spore germination of sapstain and mold fungi using plate bioassay, Southern yellow pine and sweetgum block tests, and green pine log sections: sapstain -- Ceratocystis coerulescens, Ceratocystis minor, and Aureobasidum pullulans; mold fungi -- Aspergillus niger, Penicillium spp, and Trichoderma spp. Inhibition of spore germination in plate bioassay by metabolites with boron was more effective than without added boron. Treatment of wood samples with the mixture of boron and unconcentrated metabolites also resulted in the synergistic effect and completely inhibited spore germination of sapstain and mold fungi.
S C Croan, T L Highley

Monographic cards for wood-destroying fungi. [Fiches monographiques pour les champignons lignivores]
1970 - IRG/WP I 5B
C Jacquiot

Use of vermiculite as substrate in assays on phytotoxicity of treated wood
1989 - IRG/WP 3547
It is considered the possibility of using vermiculite instead of soil as substrate in assays on phytotoxicity of wood treated with preservatives for agricultural use. Three organic preservatives were used. It had been tested the behaviour of both, vermiculite and soil in case of preservative leaking due to a leach. So that, assays of germination with cucurbitaceous were carried out, mixing a dose of preservatives with both substrates.
M V Baonza Merino, D Franco

Influence of aliphatic acids on spore germination of wood decay fungi
1984 - IRG/WP 2224
Influences of eight saturated fatty acids (C5-C10, C12 and C16) on spores of four isolates of wood decaying basidiomycetes (white rot fungi: Poria tenuis and Trametes hispida; brown rot fungus: Gloeophyllum trabeum [two isolates]) were observed in-vitro. Spore response after 24 hr on malt extract agar containing 10, 10² , or 10³ ppm of each fatty acid included: no effect on normal germination, delayed germination or restricted mycelial growth, vacuolation and degeneration of spore cytoplasm, or germination inhibition without loss of spore integrity. C7-C10 acids destroyed spores of all fungi at 10² ppm whereas spores remained 'intact' at 10³ ppm of the same acids. C12 destroyed spores of the brown rot isolates but not the white rot fungi, and C16 lacked effect on all fungi at all concentrations. C5 and C6 destroyed spores only at 10³ ppm.
E L Schmidt

Effects of a chitin synthesis inhibitor on spore germination of the decay fungi Gloeophyllum trabeum and Poria tenuis
1986 - IRG/WP 2253
This study sought to determine the effect of a chitin synthesis inhibitor - Polyoxin D, on spore germination and early hyphal development of a brown rot and a white rot fungus in-vitro. Polyoxin D is a competitive, substrate-analogue type of chitin synthtase inhibitor (2). The drawbacks to use of such a compound as a wood preservative tie. cost - $20,000/g, possible leaching or degradation) might be reduced should it be effective in preventing decay initiation by spore germination at very low concentrations.
E L Schmidt

Spore germination of Gloeophyllum trabeum on wood is related to the mass of the wood sample
1978 - IRG/WP 2118
E L Schmidt, D W French

Antagonism to spore germination in Scots pine
1990 - IRG/WP 1458
Germination of Lenzites trabea and Chaetomium globosum spores was observed directly on wood blocks, on water soluble extracts and on organic solvent soluble extracts from pine wood. In all cases pine heartwood was found to be antagonistic to spore germination but pine sapwood varied in its antagonism according to the method of drying. Chromatography revealed that extracts from antagonistic wood differed from those of non-antagonistic wood in their composition.
S M Gray

Germination of basidiospores on preservative treated wood after leaching or natural weathering
1981 - IRG/WP 2150
In tests of residual toxic efficacy after leaching or natural weathering, spore germination with Gloeophyllum trabeum has proved to be a less reliable criterion of attack than when used with unaged preservative treatments. Since spores sometimes prove more tolerant than their parent mycelium, their use should be continued.
J K Carey

Effect of sterilization method on germination of spores of wood decay fungi observed by contact agar block method
1978 - IRG/WP 2117
Previous studies of germination of spores of wood decay fungi on wood have generally concluded that method of wood sterilization has little significant effect on germination response. This study expands the numbers of test fungi as well as number of sterilization methods employed to determine the influence of sterilization method on spore germination response of decay fungi. Germination was assessed on agar discs fused by aqueous diffusion path to 1 cm³ samples of aspen and white spruce sapwood.
E L Schmidt, D W French

Studies on the biological improvement of permeability in New Zealand grown Douglas fir
1983 - IRG/WP 3231
This report outlines progress towards optimizing conditions for water storage of New Zealand grown Douglas fir with the aim of improving permeability to water-borne preservatives, in particular CCA. Small scale laboratory tests are in progress but the need to scale up to potential commercial applications is being considered. Mixed populations of bacteria isolated from 10 week water sprinkled Douglas fir are being used to inoculate green, sterile timber. Environmental parameters such as pH, temperature and nutrient status are controlled to evaluate optimum conditions of growth, enzyme production and pitmembrane degradation leading to permeability improvement.
K J Archer

In vitro studies on the effect of chitosan on mycelial growth and spore germination of decay fungi, moulds and staining fungi
2004 - IRG/WP 04-10507
The effect of solubilised, low molecular weight chitosan on established mycelial growth of a range of decay fungi, moulds and staining fungi was investigated using nutrient medium amended with different concentrations of chitosan that ranged from 0.1 to 0.4% weight per volume (%w/v). Also, spore germination of Trichoderma harzianum and Leptographium procerum was examined on chitosan amended nutrient medium using visual and microscopic assessment. The results showed that chitosan affected mycelial growth of a wide range of test fungi which generally showed lower growth rates as the chitosan concentration increased. However, the degree of inhibition exhibited by chitosan varied with fungal species. Under the present test conditions, chitosan was fungistatic, but not fungitoxic, against established mycelium of the staining fungi tested and also two moulds, Botrytis cinera and Cladosporium herbarum, but not against any of the decay fungi tested. Spores of T. harzianum germinated on chitosan amended nutrient medium at all chitosan concentrations tested, except for the highest level (0.2%w/v) used, while L. procerum failed to germinate on 0.15 and 0.2%. Also, T. harzianum and L. procerum spores incubated on 0.15% and 0.2% chitosan failed to germinate when placed onto fresh malt extract agar suggesting fungitoxic activity of chitosan at these higher concentration levels.
C Chittenden, B Kreber, N McDowell, T Singh

A rapid colorimetric assay for mold spore germination using XTT tetrazolium salt
2011 - IRG/WP 11-20462
A rapid colorimetric assay was developed to quantitate metabolic activity in mold spores during germination using 2,3-Bis(2-methoxy-4-nitro-5-sulfophenyl)-5-[9phenyl-amino)carbonyl]-2H-tetrazolium hydroxide (XTT). The assay was used to demonstrate inhibition of spore germination following exposure to different biocides and variability in the inhibition of spore germination of different mold species to the same biocide.
C A Clausen, V W Yang

The possible role of mobile CCA components in preventing spore germination in checked surfaces, in treated wood exposed above ground
2001 - IRG/WP 01-30263
Untreated check surfaces are often exposed in CCA-treated lumber of refractory species used above ground since, during weathering, some checks develop beyond the preservative penetrated zone. However, decay is seldom observed in these checks even after many years of exposure. It is hypothesized that minor amounts of mobile CCA preservative components redistribute during weathering into checks, and that this 'surface treatment' prevents fungal spores washed into checks from germinating and causing decay. A substantial amount of copper was found on the exposed check and end-cut surface in exposed wood through the current research, and whether spores are prevented from germinating by this amount of chemical is being studied.
S Choi, J N R Ruddick, P I Morris

Effect of fumigant residue in aerated wood blocks on the spore germination of decay fungi
1991 - IRG/WP 2382
Fumigants are increasingly used in several countries for remedial treatments of transmission poles to increase the service life. The present study was initiated primarily to test the remaining toxic effects of spruce (Picea rubra) wood, fumigated with chloropicrin (trichloronitro methane) or MIT (Methyl isothiocyanate) after long period of aeration, on the spore germination of decay fungi. This study indicates that spore germination of decay fungi is more sensitive than mycelia for these fumigants. An assay involving spores could therefore complement the earlier proposed open and closed tube bioassays for assessment of remaining ability to prevent reestablishment of decay fungi in fumigated wood. This assay is sensitive both to bound wood residues contributed by the fumigants as well as to fumigant vapor.
J Bjurman, B Goodell

Risk of pulmonary damage as a result of an evaporation of ca. 50 ppb = 42 mg HF, evaporated from wood treated by difluorides
1987 - IRG/WP 3401
In this review of the literature the effects of fluorides and fluorine on man are described, especially the low level effects of inhaled HF on human beings. The term "fluoride" is used as a general term everywhere, where exact differentiation between ionic and moluecular forms or between gaseous and particulate forms is uncertain or unnecessary. The term covers all combined forms of the element, regardless of chemical form, unless there is a specific reason to stress the gaseous elemental form F2, in which case the term "fluorine" is used.
H F M Nijman

Do CCA treated support stakes cause increased arsenic level in crops?
2003 - IRG/WP 03-50204
Trial of using CCA-C treated eucalypts stakes for supporting banana plants in Guangdong Province, China, began in 1998 and later it was expanded as a demonstration program of a joint International Tropical Timber Organization–Chinese Government timber preservation project in 2000. The greatest concern was whether the crop would be contaminated by the preservatives, arsenic in particular. Data from four years tracking analysis of bananas collected from the demonstration plots indicated that the arsenic levels were not significantly higher than the levels found in plants supported by untreated stakes. The arsenic content in bananas supported by preservative treated stakes was well below the level specified in food standards of China. Similar results were obtained from a trial of tomatoes and garden peas supported with treated eucalypts and round bamboo posts in pottery pots.
Li Zhaobang, Su Haitao, Liang Linqing

Effect of thickened boron in preventing conidial germination of sapwood-inhabiting fungi
1994 - IRG/WP 94-30059
We evaluated the efficacy of thickened boron preservative "Diffusolä" in preventing conidia germination of sapwood-inhabiting fungi using plate bioassay, Southern Yellow Pine and sweetgum block tests, and green pine log sections. The test fungi were sapstain fungi Ceratocystis coerulescens, Ceratocystis minor, and Aureobasidum pullulans and mold fungi, Aspergillus niger, Penicillium spp, and Trichoderma spp. Conidial germination were inhibited in plate bioassay by Diffusol. Treatment of Southern Pine and sweetgum blocks and green pine log sections with a 10 percent boric acid equivalent of Diffusol inhibited conidial germination of sapstain and mold fungi. In the field exposure, the same Diffusol treatment of green pine log sections inhibited natural basidiospore and conidial germination of forest-inhabiting fungi, thus preventing wood discoloration and deterioration
S C Croan

Inhibitory effects of leachates from Scots pine wood on germination of some wood rotting fungi
1986 - IRG/WP 1282
Leachates from sapwood of Pinus sylvestris inhibited or reduced the germination of basidiospores of the wood decay fungi tested. The fungi were selected among those preferentially colonizing hardwood or softwood, representatives for brown rot and white rot fungi, early basidiomycete colonizers and late basidiomycete colonizers in above-ground parts of pine as well as fungi found in high frequencies in window frames. In contrast, leachates from the heartwood were less inhibitory to germination of the majority of the tested fungi. Wood materials for the tests were selected to reveal differences in inhibitory effect of pine heartwood and sapwood according to: 1. Trees cut in the summer or in the winter 2. Latitude at which the trees had grown 3. Method of drying kiln-dried or air-seasoned wood No differences in inhibitory effect against the test fungi in relation to these different wood materials were revealed.
J Bjurman

Basidiospore structure and germination of Serpula lacrymans and Coniophora puteana
1988 - IRG/WP 1340
Using a nuclear staining technique and fluorescence microscopy, the basidiospores of Serpula lacrymans were shown to be uninucleate whereas those of Coniophora puteana were binucleate. The germination rate of the Serpula lacrymans spores, which was considerably lower than that of Coniophora puteana, decreased further after storage or heat treatment. Transmission electron micrographs indicate that the majority of Serpula lacrymans spores have a disorganised internal cellular structure and are filled mainly with lipidic material; these spores lack a nucleus. Germination of viable Serpula lacrymans spores occurs through the spore apiculus or through the spore apex. In contrast, Coniophora puteana spores can produce two germ tubes and germinate simultaneously through the apiculus and the apex.
B M Hegarty, U Schmitt

The ecotoxicology assessment of wood preservatives and their active ingredients by means of germination tests using cress - A critical consideration
1999 - IRG/WP 99-50125
With putting the Biocidal Products Directive 98/08/EC (BPD) in place an environmental risk assessment for wood preservatives and impregnated timber is requested. To assess possible risks, suitable test methods are required, which reveal the ecotoxicological profile including environmental fate and behaviour of treated commodities. Germination and growth tests could contribute to the determination of ecotoxicological effects on plant seeds and their embryos. Investigations were carried out in order to determine the germination and the growth behaviour of cress with the aim, to investigate the possibilities and limitations of these tests. The results show that the cress germination test is very sensitive as a rule. A prevention of the germination as such does not indicate a possible toxicity of the formulation investigated. The assessment of the germination processes as the only criterion is not a sufficient measure for the ecotoxicological profile of wood preservatives and impregnated timber. Germination tests, however, can supply a first indication concerning a possible effect on the environment. In connection with the other methods, it is possible to receive supplementary information in a very short time.
P Jüngel, A O Rapp, E Melcher

Analysis of volatile organic compounds (VOC's) from Trichoderma spp.: effect of media composition on VOC production and level of inhibition of wood decay fungi
1997 - IRG/WP 97-10207
Production of volatile organic compounds (VOC's) by two Trichoderma isolates grown on either malt extract or minimal media was examined and statistically assessed to identify which VOC's were predominantly produced on each of the two media types. The VOC's were captured onto chromatographic absorbent from above the cultures of the fungi before being analysed by integrated Automated Thermal Desorbtion- GC-MS. In addition the inhibitory effects of the VOC's were assayed against four common wood decay fungi. Although the VOC's produced on the malt media consistently inhibited the target fungi, effects were negligible when the fungi were grown on the minimal medium. A total of 45 individual VOC's were identified however statistical analysis by principal component analysis indicated that only 5 were implicated in the inhibition of the decay fungi. The likely importance of volatiles in the biological control of wood decay fungi is discussed.
A Bruce, R E Wheatley, C Hackett, A Kundzewicz

The effect of added nutrients on growth rate and decay capacity of Serpula lacrymans
1990 - IRG/WP 1427
At the previous meeting a new technique was presented that enables both fungal growth rate and wood decay rate to be measured using the same timber specimen. The technique (IRG/WP/1384) has previously been carried out with 1% malt as the sole nutrient within the small jar that provides the inoculum for this method. Results presented here relate to an additional level of 5% malt, with or without a nitrogen source in the form of ammonium sulphate at either 0.01 g or 1.0 g per litre. Two isolates of Serpula lacrymans (one of European and one of Australian origin) were used at a temperature setting of 20°C. The linear growth front was measured, on the 200 mm long specimens of Pinus radiata sapwood, between 10 and 21 days after the specimens were introduced to the inoculum. Mass loss values of these same specimens were determined after 12 weeks' exposure. Replication comprised three specimens, within each of three large jars, of each treatment. For both strains, increasing the malt level caused some reduction in growth rate, with the addition of nitrogen resulting in no further growth rate changes. In contrast, mass loss of timber was increased for both strains at the higher malt level. Furthermore, for each of the two malt levels tested, the mass loss due to both strains was further increased at the high nitrogen level.
J D Thornton, A McConalogue

A case for ecosystem-level experimentation - A discussion paper
1986 - IRG/WP 1296
Although laboratory bioassays provide a first step in testing for potential termiticides and assist in formulating recommendations of these chemicals for regulatory agencies and users, they are not designed for predicting effects on natural populations (including humans) and on ecosystem-level features. To overcome this we need microcosm studies, carefully controlled experimental manipulations of whole ecosystems run in parallel with laboratory bioassays, the gathering of long term field data, and a sound theoretical basis for extrapolation.
J R J French

Basidiospore germination threshold against borate in-vitro may vary between liquid and agar media
1992 - IRG/WP 92-2405
The concentration of disodium octaborate (BAE) which prevented mycelial growth of a common brown rot and 3 white rot fungi was compared to that required to prevent basidiospore germination on malt extract agar. Spore germination sensitivity was lower (50%) for only one of the white rot fungi. However, when spore germination thresholds were tested in malt extract-borate solutions in well slides (no agar), much lower thresholds were noted for 3 of 4 fungi. Neither set of threshold data predicted that noted in limited tests on aspen (Populus tremuloides).
E L Schmidt, Ya-Lih Lin

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