• Journal of Korean Society of Forest Science
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• v.99 no.2
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• pp.251-257
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• 2010

Influences of environment (indicated by plant associations) and forest management practices on the distribution of Armillaria spp. and genets (vegetative clones) were investigated. A total of 142 isolates of Armillaria was collected from various host trees on pristine and managed sites (thinned and/or fertilized) growing in relatively wet and dry environments in eastern Washington, U.S.A. The incidence of Armillaria spp. was significantly higher in the relatively wetter sites than the relatively drier sites, as indicated by plant associations. However, no differences in Armillaria occurrence were found among different forest management practices (control vs. thinned vs. thinned and fertilized) within both wetter and drier sites. Incidence of Armillaria was significantly different among conifer and shrub species. The highest proportion with Armillaria was found on grand fir (Abies grandis). Based on pairing tests and rDNA sequencing, the 142 isolates were comprised in a total of 20 genets representing three Armillaria species. More diverse Armillaria spp. were found in both relatively wetter and relatively drier sites within the undisturbed control plots, compared to plots disturbed by forest management practices. The results from this study provide baseline information toward understanding how environment and forest management practices influence incidence and diversity of Armillaria species and genets.

• The Plant Pathology Journal
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• v.39 no.6
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• pp.548-565
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• 2023

Armillaria root disease affects forests around the world. It occurs in many habitats and causes losses in the infested stands. Weather conditions are important factors for growth and development of Armillaria species. Yet, the relation between occurrence of damage caused by Armillaria disease and weather variables are still poorly understood. Thus, we used generalized linear mixed models to determine the relationship between weather conditions of current and previous year (temperature, precipitation and their deviation from long-term averages, air humidity and soil temperature) and the incidence of Armillaria-induced damage in young (up to 20 years old) and older (over 20 years old) coniferous stands in selected forest districts across Poland. We used unique data, gathered over the course of 23 years (1987-2009) on tree damage incidence from Armillaria root disease and meteorological parameters from the 24-year period (1986-2009) to reflect the dynamics of damage occurrence and weather conditions. Weather parameters were better predictors of damage caused by Armillaria disease in younger stands than in older ones. The strongest predictor was soil temperature, especially that of the previous year growing season and the current year spring. We found that temperature and precipitation of different seasons in previous year had more pronounced effect on the young stand area affected by Armillaria. Each stand's age class was characterized by a different set of meteorological parameters that explained the area of disease occurrence. Moreover, forest district was included in all models and thus, was an important variable in explaining the stand area affected by Armillaria.

• The Korean Journal of Mycology
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• v.23 no.1 s.72
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• pp.61-70
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• 1995

The genus Armillaria is important because they produce Gastrodia tubers. Seventy two isolates of Armillaria were obtained from fruit bodies grown on decayed wood in Korea. Twenty four isolates from Pinus koraiensis were identified as A. ostoyae. Two isolates from G. elata growing in the field were identified as A. mellea. Seven isolates from Acer ginnala and Quercus spp. were identified as A. tabescens. Thirty nine isolates were identified as A. gallica. Armillaria gallica was isolated from Quercus spp., Ainus japonica, Vitis amurensis and Prunus sargentii. Armillaria spp. isolates were divided into four groups based on the cultural characteristics. Group II (A. gallica KNU-A110) was better than the other groups for mycelial growth and rhizomorph formation. Isolate KNU-A110 proved to be good for production of G. elata tubers. This fungus forms mycelial fan in the plant tissue and rhizomorphs in contact with G. elata tubers. Gastrodia spp. was found in thirteen sites in Kangweon province in Korea. The plants were divided into three different kinds based on stem color. Plants with stems of brownish orange and greyish yellow were identified as G. elata, and those with greyish green colored stems were identified as G. gracilis. Gastrodia was collected mainly from humus soils rich in leaf debris, and slopes facing south from mid-May to mid-July. Once the new tubers are formed from the ancestry tuber, the ancestry tuber begins to decay. The offspring tuber, apparently gaining nutrients through rhizomorphs, begins to grow in length and slowly to enlarge. It takes three years for the offspring tuber to become ancestry tuber.

• The Korean Journal of Mycology
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• v.46 no.3
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• pp.255-269
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• 2018

Armillaria is a white-rot fungus that decomposes organics; it is also a root pathogen that kills trees. Recently, since the forest tending practice, the incidence of Armillaria infections on tree stumps has been increasing. Herein, we have examined the morphological features of Armillaria solidipes and A. gallica collected from 10 areas in Korea, and investigated the activities of the decomposing enzymes cellulase and laccase of these two Armillaria species. A. solidipes was found in eight host tree species including Pinus densiflora, Quercus serrata, and Castanea crenata at the altitude of 107~1,396 m, while A. gallica was found in three host species including P. densiflora and Fraxinus rhynchophylla at the altitude of 119~556 m. The fruiting bodies of A. solidipes are close with lamellae, and have brown to black hairs on the stipe, while those of A. gallica are distant with lamellae and clavate-shaped, and have yellow hairs on the base. The activites of cellulase of the two species were not different, but the activity of A. solidipes laccase was higher ($12.94{\pm}0.4U/mL$) than that of A. gallica laccase ($9.14{\pm}0.3U/mL$).

• The Korean Journal of Mycology
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• v.20 no.3
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• pp.273-276
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• 1992

Armillaria mellea mushrooms were cultivated on the sawdust media, Quercus sawdust; rice bran=80:20 in polypropylene bags. The isolate of Armillaria mellea used was ARM69002F collected from a Korean pine plantation in Hongcheon district. The length of time between spawning and fruiting was required for 90 to 100 days. The number of fruiting bodies produced in a bags with a kg substrate were approxinately 31 (range of 18 to 62), and the total fresh weight 158g (61 to 207g), converted to 13 to 15% of fresh weight. The pilei of fruiting bodies were average 4.0 cm (2.5 to 7.6 cm)wide, and their stipes 8.2 cm long and 0.6 cm-thick at the upper part and 1.2 cm at the base.

• The Korean Journal of Mycology
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• v.45 no.1
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• pp.1-13
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• 2017

Armillaria species are non-obligate root pathogens, as well as facultative parasites. The genus consists of about 40 species with worldwide distribution that are difficult to identify morphologically. Their hosts include conifers, hardwoods, vines, and even herbs. These fungi contribute to natural thinning and succession of vegetation in forests and decompose wood to develop edible fruiting bodies from spring to autumn. Its genets have a lifespan of up to 2000 years and have been found to occupy as much as 960 ha of forest land. Recently, forest tending work such as thinning of forests has resulted in the creation of tree stumps that support the growth of Armillaria, and these mushrooms have become an income source in mountainous areas. Therefore, identification of these species is needed. We review the difficulties in identification, suggest a species identification key for Korean indigenous species, and discuss the significance of Armillaria in terms of forest ecology and plant pathology.

• Journal of Korean Society of Forest Science
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• v.50 no.1
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• pp.10-15
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• 1980

This experiment was carried out to know the effects of artificial apawning of Armillaria matsutake in the Pinus densiflora stands. The results obtained were as followed: 1. The inoculation experiment resulted in only the development of hypha in the spore-spread plot and there appeared 2 fruit bodies in the spore injection plot and 4 fruit bodies in the hypha-transplanted plot. 2. The spore flushing plot method was considered a recommendable one in view of labor problem. 3. It was seemed that Armillaria matsutake was not a commensal fungus but a parasitic ectotrophic mycorhiza to pine trees since pine trees in the Armillaria matsutake-appearing plot grew remarkably slow comparing with the non-appearing plot. 4. Armillaria matsutake appearance only in 20 to 60 year-old pine trees seems to have a correlation with a special matter. Therefore the experimenter thinks that Armillaria matsutake spores must be inoculared only with 20 to 60 year-old pine trees.

• Korean Journal Plant Pathology
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• v.10 no.4
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• pp.261-269
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• 1994

One hundred and ninety two isolates of Armillaria were obtained from mycelial fans on infected hosts, rhizomorphs, and single basidiospores or trauma tissue of fruiting bodies. Mating tests showed that two of these isolates were A. mellea, eight were A. tabescens, 20 were A. ostoyae, and 162 were A. gallica. Armillaria ostoyae was mainly isolated from Pinus koraiensis and Qurecus spp., A. tabescens from fruiting bodies on Pinus densiflora and Qurecus spp., and A. gallica from many tree species but not Pinus koraiensis. Armillaria mellea, A. gallica, A. ostoyae and A. tabescens showed distinct protein banding patterns. Mycelial growth and rhizomorph formation was good on basal medium with ethanol added. A. gallica and A. mellea formed many rhizomorphs, but A. ostoyae did not. A. gallica showed the best rhizomorph formation on media with tannic acid and ethanol, but a. mellea formed the most rhizomorphs on gallic acid. Rhizomorphs showed monopodial branching for A. gallica and dichotomous branching for A. ostoyae. Fruiting bodies. formed in the laboratory on sawdust media most abundantly by A. tabescens. In nature, fruit body formation by A. tabescens was from early to mid August. A. ostoyae and A. gallica fruit bodies were formed from early August to late October. While there are common names in Korea for A. mellea and A. tabescens, such as mulberry mushroom relative, no common names are available for A. gallica and A. ostoyae. Therefore, we refer to a. gallica as the Gastrodia mushroom because it has been used to produce Gastrodia and A. ostoyae as the Korean pine mushroom because it is frequently found as mushrooms on Korean pine.

• Journal of Mushroom
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• v.10 no.3
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• pp.143-149
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• 2012

Armillaria spp are well known as a symbiotic fungus with Gastrodia elata. This study was carried out to identify and analyze the genetic relationships among 83 strains of Armillaria spp.. The amplified internal transcribed spacer(ITS) region of the rDNA was about 500~750 bp long and identified by 9 strains; A. mellea, A. tabescens, A. ostoyae, A. gallica, A. novae-zenlandia, A. cepistipes, A. nabsnona, A. gemina, A. sinapina. Sequence analysis showed that 52% of strains were different with original identification. A. gallica, A. cepistipes and A. gemina were so close phylogenetic relationship, that was difficult to classify using ITS region. In A. gallica, 12 strains including ASI10104 were showed a close phylogenetic relationship with A. gallica, A. cepistipes and A. gemina. ASI10017 and ASI10114 were classified as the A. sinapina group, ASI10045 was the A. borealis group, ASI10002 and ASI10025 were the A. ostoyae group. So more studies need for more accurate identification and determine the phylogenetic relationships of Armillaria spp.

• The Korean Journal of Mycology
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• v.18 no.3
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• pp.158-163
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• 1990

To investigate symbiotic relationship of 'Chunma (Gastrodia elata) and the rhizomorph of Armillaria mellea, volatile organic acids and alcoholic compounds which were considered to be contained in Gastrodia elata were tested to determine stimulatory effects on rhizomorph growth on a chemically defined medium. Also, volatile organic acids were isolated from Gastrodia elata and analyzed by gas chromatography. The growth of rhizomorph was stimulated by the presence of alcohols and volatile organic acids, but acetic acid and methanol were ineffective. In the presence of valeric acid and ethanol, Armillaria mellea produced abundant rhizomorph at concentrations of 0.1 and 1%, respectively. Ethanol and valeric acid supplemented at regular intervals of 3 days as lower concentrations in the medium stimulated the growth of Armillaria mellea. The concentrations of ethanol and valeric acid as low at 0.01% added 3 days intervals for 15 days were more effective than initial concentrations of 0.1 and 1% in stimulating rhizomorph development of Armillaria mellea. Eight kinds of volatile organic acids were identified and quantified by gas chromatography. The major compounds were n-propionic, valeric, iso-carproic and caproic acids, and the minor compounds were iso-butyric, butyric, iso-valeric and hepatanoic acids. Valeric acid was the most abundant among them.