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The systematic study of aphyllophoroid, including hymenochaetoid, fungi in Armenia revealed around 200 species, forms, and varieties among which around 40 species possess medicinal properties. The modern taxonomic analysis and nomenclature verification of mycobiota of macromycetes are required for assessment of the resource value of Armenian medicinal mushrooms. According to Index Fungorum the hymenochaetoid fungi (order Hymenochaetales) is currently represented by 27 species, 14 genera, and 3 families. Among them, Phellinus tremulae has originally been reported for Armenian mycobiota; 12 species possess pharmacological properties. The current review addresses the biodiversity, resource value, bioactive and pharmacological properties, as well as perspectives for further biotechnological exploitation of hymenochaetoid fungi in Armenia.

During the course of a study on the functional biodiversity of the mycobiota inhabiting rainforests in Thailand, a fungal strain was isolated from a plant sample and shown to represent an undescribed species, as inferred from a combination of morphological and molecular phylogenetic methods. Molecular phylogenetic analyses, based on four DNA loci, revealed a phylogenetic tree with the newly generated sequences clustering in a separate branch, together with members of the Sulcatisporaceae (Pleosporales, Ascomycota). The Thai specimen morphologically resembled Neobambusicolastrelitziae in having pycnidial conidiomata with phialidic conidiogenous cells that produce both fusoid-ellipsoid macroconidia and subcylindrical microconidia. However, the new fungus, for which the name Pseudobambusicolathailandica is proposed, differs from N.strelitziae in having conidiomata with well-defined necks, the presence of globose to subglobose thick-walled cells adjacent to conidiomata and the production of chlamydospores in culture. When cultures of P.thailandica, growing on water agar, were confronted with Caenorhabditiselegans nematodes, worms approaching the fungal mycelia were killed. This observation gave rise to a study of its secondary metabolites and six novel and two known compounds were isolated from submerged cultures of P.thailandica. The structures of metabolites 1–6, for which the trivial names thailanones A–F are proposed, were elucidated using a combination of spectral methods, including extensive 1 and 2D NMR analysis and high resolution mass spectrometry. Compounds 4 and 8 showed strong nematicidal and weak antifungal activity, whereas all other tested compounds showed moderate to weak nematicidal activity but no significant effects in the serial dilution assay against various fungi and bacteria. Compounds 1 and 8 also inhibited growth of the pathogenic basidiomycete Phellinustremulae in a plate diffusion assay.

Populus tremuloides Michx. is an iconic tree of the mountains of the western United States. In Utah, it very commonly suffers from white trunk rot caused by Phellinus tremulae (Bondartsev) Bondartsev & P.N.Borisov. The incidence of this disease is affected by tree and site characteristics, but the magnitude of these effects appears to be site-dependent. To minimize harvest wood loss in Utah, we determined the locally important factors that explain the wide variation in the incidence of sporocarps of Phellinus tremulae. To avoid confounding of factors, we utilized a multiple regression approach. We found that while the incidence of Phellinus tremulae sporocarps on quaking aspen was always low at high elevations, it was variable at low elevations. Our logistic regression model indicated that variation in the incidence of sporocarps at low elevations was attributable, in part, to variation in aspect, slope, environmental stress, and tree age and size. Based on these results, we recommend that harvesting at elevations below 2500 m be confined to younger trees or to sites on relatively steep, north-facing slopes. Because of site-dependency, the same general method could be used to establish harvesting criteria in other regions.

A rampant highly heterozygous aspen (Populus tremula L.) clone “Meshabash” has been revealed in course of population genetic diversity analysis in a native stand in the Republic of Tatarstan, Russia. Here we report the results of karyological analysis showing that this highly vigorous clone is diploid (2n=38) while typically triploid aspen demonstrates increased growth rate and resistance to aspen trunk rot caused by fungus Phellinus tremulae. By means of DNA identification of a series of model trees using 14 SSR loci we outlined the area occupied by this clone (at least 1.94 ha) and demonstrated that its ramets constitute 40 out of 48 genotyped trunks on the plot with the maximal distance between ramets 254 m. Since aspen is able to regenerate after cutting or die-off of maternal tree by root suckers at a distance up to 20–35 m this assumed that current stand appeared as a result of such spreading from an ortet tree during at least 5 generations. Trunk rot damage in the wood of model trees indicated low influence of this pathogen on viability and performance of the studied clone that can be associated with its extreme heterozygosity level (0.926) exceeding all the studied trees in this research plot and in three other control samples.

Some peculiarities of expansion characteristics and general dynamics of the forest disease cores in Volyn region were studied in Volyn Regional Forestry and Hunting Industry Administration (VRFHIA). The dynamics of sanitary selective and solid felling with area distributions connected with VRFHIA in 2016 was illustrated. The main problems and tendencies of forest sanitary conditions were explained. The area of lesions the most dangerous forest diseases for 2016 if found to increase by 954.8 ha or 3.8 %. Having analysed Volyn region forest sanitary condition the authors have ascertained that generally 1220.5 ha of disease cores were eliminated by means of forest protection activities and written off during the report year. The biggest size is the concentration of Root fungus (Heterobasidion annosum (Fr.) Bref. 1889) and it remained the same as in the previous years. It covers 13961 ha or in other words it is 55 % of general surface of disease cores in this region. 5117 hectares need some methods of felling. Root fungus (Heterobasidion annosum (Fr.) Bref. 1889) has developed rapidly because of the long lasting drought season and the ground water level decrease. During 2016 Volyn RFHIA enterprises tried to solve the problem by solid sanitary felling in the areas of 332 ha with disease concentration. This is 2.4 % of the general land area of these nucleuses. The most common forest diseases are defined to be as follows: stem rot (Fomes fomentarius (L) Fr.1849) – 2363 hа; aspen fungus (Phellinus tremulae (Bondartsev & P. N. Borisov 1953) – 993 hа; diametrical Oak cancer (Pseudomonas quercus Schern.) – 922 hа; oak fungus (Daedalea quercina (L.) Pers.1801) – 676 hа; birch polyporus (Piptoporus betulinus (Bull.) P. Karst.1881) – 657 hа; red rot (Phellinus pini) – 562 hа; pitch streak (Cronartium flaccidum (Alb. & Schwein.) G. Winter 1880) – 369 ha; alder fungus (Phellinus igniarius (L.) Quél. 1886) – 313 ha; bacterial ash cancer (Pseudomonas savastanoi (Janse 1982) Gardan, et al., 1992) – 216 ha; much smaller (Armillariella mellea (Vahl) P. Kumm. 1871) – 183 hа. In order to protect and preserve forests when forestry proceedings, a complex of sanitary and recreational events and sanitary requirements are taking place., Розглянуто особливості поширення та динаміку розвитку осередків хвороб в лісах Волинської області. Відмічено, що динаміка осередків хвороб лісу є негативною в лісопатологічному відношенні, а площа осередків найбільш небезпечних хвороб лісу за 2016 р. збільшилась на 954,8 га або 3,8%. Висвітлено основні проблеми та тенденції санітарного стану лісів та дана характеристика осередків хвороб лісу в розрізі Волинського ОУЛМГ. Показано динаміку санітарних рубань вибіркових та суцільних за останні 10 років та розподіл СРС по причинах розладнання в розрізі Волинського ОУЛМГ. Проаналізувавши санітарний стан лісів Волині встановили, що в загальному ліквідовано заходами боротьби та списано протягом звітного року 1220,5 га осередків хвороб, затухли під дією природних факторів 539,7 га осередків хвороб, виникло протягом року 2716,8 га нових осередків. Виявлено, що найбільшим осередком хвороб по площі є коренева губка (Heterobasidion annosum (Fr.) Bref. 1889). Її площа, в порівнянні з попередніми роками, збільшилась на 4,5 % і становить 13961 га. В 2016 році виникло 1590 га осередків кореневої губки, а ліквідовано заходами боротьби 708 га. Встановлено, що досить поширеними хворобами по площі в лісах області є стовбурова гниль (Fomes fomentarius (L)Fr.1849) – 2363 га, осиковий трутовик (Phellinus tremulae (Bondartsev & P.N. Borisov 1953) – 993 га, поперечний рак дуба (Pseudomonas quercus Schern.) – 922 га, несправжній дубовий трутовик (Daedalea quercina (L.) Pers.1801) – 676 га, березова губка (Piptoporus betulinus (Bull.) – 657 га., Рассмотрены особенности распространения и динамику развития очагов болезней в лесах Волынской области. Отмечено, что динамика очагов болезней леса является отрицательной в лисопатологичного отношении, а площадь очагов наиболее опасных болезней леса за 2016 увеличилась на 954,8 га или 3,8%. Освещены основные проблемы и тенденции санитарного состояния лесов и дана характеристика очагов болезней леса в разрезе Волынского ОУЛОХ. Показана динамика санитарных рубок выборочных и сплошных за последние 10 лет и распределение СРС по причинам расстройство в разрезе Волынского ОУЛОХ. Проанализировав санитарное состояние лесов Волыни установили, что в общем ликвидировано мерами борьбы и списаны в течение отчетного года 1220,5 га очагов болезней, затухла под действием природных факторов 539,7 га очагов болезней, возникло в течение года 2716,8 га новых очагов. Выявлено, что самым центром болезней по площади является корневая губка (Heterobasidion annosum (Fr.) Bref. 1889). Ее площадь, по сравнению с предыдущими годами, увеличилось на 4,5% и составляет 13961 га. В 2016 году возникло 1590 га очагов корневой губки, а ликвидировано мерами борьбы 708 га. Установлено, что достаточно распространенными болезнями по площади в лесах области является стволовая гниль (Fomes fomentarius (L) Fr.1849) – 2363 га, осиновый трутовик (Phellinus tremulae (Bondartsev & PN Borisov 1953) – 993 га, поперечный рак дуба (Pseudomonas quercus Schern.) – 922 га, ненастоящий дубовый трутовик (Daedalea quercina (L.) Pers.1801) – 676 ​​га, березовая губка (Piptoporus betulinus (Bull.) – 657 га.

Increases in mortality of trembling aspen (Populus tremuloides Michx.) have been recorded across large areas of western North America following recent periods of exceptionally severe drought. The resultant increase in standing, dead tree biomass represents a significant potential source of carbon emissions to the atmosphere, but the timing of emissions is partially driven by dead-wood dynamics which include the fall down and breakage of dead aspen stems. The rate at which dead trees fall to the ground also strongly influences the period over which forest dieback episodes can be detected by aerial surveys or satellite remote sensing observations. Over a 12-year period (2000-2012), we monitored the annual status of 1010 aspen trees that died during and following a severe regional drought within 25 study areas across west-central Canada. Observations of stem fall down and breakage (snapping) were used to estimate woody biomass transfer from standing to downed dead wood as a function of years since tree death. For the region as a whole, we estimated that >80% of standing dead aspen biomass had fallen after 10 years. Overall, the rate of fall down was minimal during the year following stem death, but thereafter fall rates followed a negative exponential equation with k = 0.20 per year. However, there was high between-site variation in the rate of fall down (k = 0.08-0.37 per year). The analysis showed that fall down rates were positively correlated with stand age, site windiness, and the incidence of decay fungi (Phellinus tremulae (Bond.) Bond. and Boris.) and wood-boring insects. These factors are thus likely to influence the rate of carbon emissions from dead trees following periods of climate-related forest die-off episodes.

To better understand the potential long-term effects of biomass harvesting on biodiversity, the polyporoid fungi community was characterized from 120 plots in four aspendominated forests in Minnesota. Four deadwood variables (substratum species, substratum type, decay class and diameter class) were recorded for each polyporoid species occurrence. A total of 2358 polyporoid occurrences, representing 86 species, were recorded on 16 tree species. Eight species (Trichaptum biforme, Bjerkandera adusta, Trametes hirsuta, Phellinus tremulae, Fomes fomentarius, Irpex lacteus, Fomitopsis ochracea and Antrodia serialis) made up 67 % of occurrences. Four polyporoid species (Funalia trogii, Pycnoporellus fulgens, Rigidoporus crocatus and Skeletocutis chrysella) are potentially rare and/or threatened in the Lake States. Non-metric multidimensional scaling and rarefaction curves demonstrated that small diameter substrata (especially those

Cavity excavators (woodpeckers, chickadees, nuthatches) are vulnerable to loss of old forest associated with traditional harvest practices. In the boreal plains of Canada, old forest excavators are retained in the short term in small ( 35 cm) and tall (>25 m) trembling aspen (Populus tremuloides) with multiple (∼20) conks of a heartrot fungus (Phellinus tremulae) were the preferred cavity trees for yellow-bellied sapsucker (Sphyrapicus varius), hairy woodpecker (Picoides villosus), and pileated woodpecker (Dryocopus pileatus). Short (∼10 m), broken-top aspen snags of medium (>20 cm) and large (>35 cm) diameter were preferred by black-capped chickadees (Poecile atricapillus) and northern flickers (Colaptes auratus), respectively. In the harvests, sapsuckers, hairy woodpeckers, and flickers selected cavity trees in clumps with other medium- and large-diameter aspen with conks. Black-capped chickadees selected trees with no live large conifers within ∼10 m. Sapsuckers selected old aspen and mixedwood stands in intact landscapes. In harvest landscapes, sapsuckers selected trees in or near planned patches greater than 5 ha and composed of mature and old aspen and mixedwood stands. Sapsuckers tended to nest in areas with ∼50% residual forest cover whereas flickers selected open areas of cutblocks away from planned patches. We recommend harvest operators retain several live, large (>35 cm dbh) aspen with numerous (∼20) fungal conks in clumps that are adjacent to or near ( 5 ha) patches. Planned patches should have one to two thirds of their area derived from mature and old aspen and mixedwood stands and should be at least 5 ha, with most greater than 15 ha. These prescriptions will facilitate retention of the cavity-using assemblage of old upland forest in aggregated harvests in the short term. However, regional strategies for old forest conservation may be necessary to conserve cavity users in managed forest landscapes over the long term.

In northern Europe, the biologically rich European aspen (Populus tremula) tends to disappear both from intensively managed and strictly protected forests, thus representing a biodiversity conservation challenge. This study describes the distribution of Aphyllophoroid fungi inhabiting aspen in a hemiboreal mixed-forest landscape where clear-cutting was usually followed by natural regeneration. In a 4-km2 area in Estonia, 181 individual forest stands and cut areas were surveyed. Sixty-one percent of the 2831 live aspen trees found were concentrated in 11% of the area. Thirty-six polypore species were recorded on aspen, with old stands and naturally created deadwood hosting most species. Among the records of 14 pre-defined aspen-specific basidiomycetes, Phellinus tremulae comprised about 95%. Six species (Ceriporiopsis aneirina, Clavicorona pyxidata, Funalia trogii, Phellinus populicola, Rigidoporus corticola, Steccherinum pseudozilingianum) were infrequent to rare, but widely distributed, inhabiti...

Phellinus tremulae is an important fungal decay agent common to aspen and a critical component to the cavity-nesting bird complex found in western aspen stands. Little information exists on the conditions that facilitate infection and spread of P. tremulae in aspen forests. I used Forest Inventory and Analysis (FIA) data to explore the relationships of several tree and stand characteristics to the presence and frequency of P. tremulae in aspen measured across several western states of the United States. Results suggest a strong relationship between tree age, tree diameter, and compacted crown ratio with infection frequency in trees while stand purity, canopy cover and stand age had a positive relationship with the occurrence of P. tremulae in forest stands containing aspen. Logistic regression modeling identified stand age as the only variable that increased the odds of predicting infection at the stand-level while all tree-level variables were included in the tree model. Data also show that infection rates in the study area were lower than in other parts of aspen's range, and that average size of infected trees was smaller in the study area than those reported elsewhere. These results have important implications to management of aspen for wildlife, especially for birds that use decayed aspen for nesting.

This study was based on different susceptibility of Populus tremula clones to Phellinus tremulae, the major pathogen of this tree species. As the conventional resistance genes detection is time consuming and expensive, it is important to find other applicable methods to recognize resistance genes of the plants. The aim of this study was the assessment of correlation between various genetic population parameters and phenotipic, resistance or highly heritable traits of individual P. tremula trees. In this study we investigated all Lithuanian P. tremula plus trees from 16 populations in 3 provenance regions. Investigated trees were analyzed using RAPD, SSR and PCR-RFLP methods, and their individual and population genetic parameters as well as infection incidence with P. tremulae were assessed. Determined genetic parameters were examined for correlation with P. tremulae infection. Only two out of 292 RAPD loci were significant for damaged and undamaged by P. tremulae groups of trees. The resistance of investigated European aspen plus trees with P. tremulae showed no dependency on the population, provenance region or individual tree heterozygosity. RAPD loci linked to infection should be investigated further, to confirm or reject their value in assesing individual tree susceptibility to P. tremulae and the genetic mechanisms underlying such correlation.

The investigation of tree-cavity habitat in north-central British Columbia’s sub-boreal forests is growing in importance as pressures on the forest landbase increase. Bats are one group of species that rely on tree cavities in these forests, particularly for communal maternity roosting. Suitable sites are crucial for viability of the population. We investigated the development and characteristics of six trees used by bats as maternity roosts. Maternity colonies were found in naturally formed cavities in live, decadent aspen in old stands. These confirmed maternity roost trees and four other trees with similar characteristics without bats, were sampled. Confirmed roost trees had a mean cavity size of approximately 282,700 cm3, a mean wall thickness of 13.4 cm, and minimum wall thickness of 8.0 cm (includes solid and decayed wood). Identified fungi involved in creating the cavities were Phellinus tremulae, a true heartrot, and Armillaria sinapina, a root rot. A. sinapina was not expected to be associated with bat habitat as it typically acts as a butt rot which creates cavities near the base of the tree; however, bats were seen using roosts with entrances starting as low as 10 cm. Both pathogens require time to develop advanced decay, therefore cavities are more prevalent in older trees. Older trees are also larger, have more heartwood than younger trees and may provide larger cavities with thicker walls. These features may contribute to a more stable and warmer microclimate, which accelerates fetal development and juvenile growth. Forest managers must recognize the importance of old aspen and monitor the availability and quality of bat roosting habitat to ensure populations are not threatened when forests are managed primarily for commercial timber harvesting.

Advanced decay caused by Phellinus tremulae was estimated in 295 trembling aspen on 30 plots in 2 Minnesota counties using existing inventory guides, and then measured by felling and sectioning the trees. In standing trees, decay volume was underestimated by 38% compared to measured decay volume in felled trees. The most reliable external indicator of decay was the presence of conks of the fungus. Results indicate that decay associated with conks in the first 16 ft of the trees accounted for nearly 70% of the total volume loss. Decay volume in trees with no conks averaged less than 2% compared to 14% in trees with conks. There was little merchantable volume lost from decay associated with poplar borer (Saperda calcarata) damage, closed wounds, and hypoxylon cankers. We recommend that inventory guides for estimating aspen decay in Minnesota be revised, and a suggested guide is provided. North. J. Appl. For. 15(1):33-36.

Summary Phellinus tremulae is the most important decay fungus on Populus tremuloides. In forest industries using aspen wood chips, two blue-stain fungi Ophiostoma crassivaginatum and Ophiostoma piliferum cause considerable reduction in the value of the end product. Thirty-eight homologues and analogues of 4-phenyl-3-butenoic acid were studied against P. tremulae, O. crassivaginatum, and O. piliferum. Varied inhibition of the in vitro growth of these fungi was observed at 1–1000 μg/ml. The wood-chip colonization by P. tremulae was not affected by the six most active compounds at 1 μg/ml, however, at 10 and 100 μg/ml the growth of P. tremulae on wood chips was totally arrested. 4-Phenyl-3-butenoic acid and 4-phenyl-3-butynoic acid prevented blue-stain development on wood chips at 1 μg/ml.

Basidiocarps of Phellinus tremulae were col­ lected from trembling aspen (Populus tremuloides) in Alberta, Saskatchewan, and Ontario. A mating study based on single spore isolates of 12 of these basido­ carps was performed using carrot agar, malt agar, and malt-yeast agar media. Results from carrot agar showed that the fungus is heterothallic and has a tetrapolar mating system. Mating studies on malt agar and malt­ yeast agar were inconclusive. The mating factor genes were multiallelic. Compatible and incompatible mat­ ings could be recognized microscopically. Radial growth rate of heterokaryon colonies did not differ significantly from that of homokaryon colonies. When genetically different heterokaryotic isolates were paired on agar media a zone of antagonism formed where the two colonies met. No zone of antagonism occurred between genetically identical heterokaryon colonies.

Trembling aspen (Populustremuloides Michx.) bearing certain types of black galls have a lower incidence of Phellinustremulae (Bond.) Bond. & Boriss. heartwood rot than do nongall-bearing trees. Extraction of finely ground black gall tissue with ethyl acetate and separation of the acidic components of the extract led to the isolation of benzoic acid, trans-cinnamic acid, p-hydroxybenzoic acid, p-hydroxycinnamic acid, naringenin, 7′-methyl-3-hydroxynaringen, aromadendrin, and taxifolin. Bioassays revealed that among these compounds, only benzoic acid showed significant activity against P. tremulae. An analytical procedure was developed to measure the concentration of benzoic acid in various types of aspen tissue. Tissue from the black galls showed a high concentration of benzoic acid, and tissue from gall-bearing trees contained significantly more benzoic acid than healthy nongalled trees. However, the amount of benzoic acid present in the gall-bearing trees may not be sufficient to prevent Phellinus decay. It is suggested that perhaps the benzoic acid serves as a precursor of salicylic acid, a signal molecule in systemic acquired resistance of plants.

Large black stem galls occur sporadically on trembling aspen (Populus tremuloides) in western Canada. Although little is known about their cause or structure, trees having these galls are less likely than surrounding aspen to have advanced decay caused by the fungus Phellinus tremulae. The anatomy and histochemistry of black galls and associated branch galls were studied and compared with normal wood and bark. Light microscopy showed that the cambium of black galls produces greater numbers of cells per growth ring and that growth rings are two to three times wider than normal. Vessel elements and fibers are unusually small and misshapen. Gall xylem has characteristics associated with wounding or infection: ray cells filled with phenolic deposits, and vessel elements occluded by tyloses and granular material. Frequent radial strands of undifferentiated callus tissue surrounded by necrophylactic periderms indicate sites of cambial damage of unknown cause. White areas within dark-colored gall xylem of some samples were free of most of these abnormalities, suggesting that a persistent agent is required for continuing tumor growth. Thickened outer bark harbored a variety of saprophytic fungi, especially hyphomycetes. Surface and internal morphology of black galls was also compared with similar stem galls caused by poplar budgall mites (Aceria parapopuli) and was found to be different. Bacteria, fungi, or mites were not obvious within living tissue, and further studies are necessary to determine the etiology of black galls. Key words: Populus tremuloides, poplar, black gall, wood anatomy.

Efficient use of trembling aspen (Populustremuloides Michx.) is often limited by the presence of extensive decay and stain. Aspen trees with black stem galls of unknown cause reportedly have less advanced decay caused by the fungus Phellinustremulae (Bond.) Bond. & Boriss. than do adjacent trees without galls. Nine field sites having large numbers of galled aspen were surveyed for the presence of P. tremulae conks. Logistic regression showed that the odds of a gall tree having at least one conk was 44% of that for trees without galls, and that the occurrence of conks varied among sites and increased with increasing tree diameter. Inclusion of black galls in models used to predict decay might result in greater accuracy on sites where these galls are prevalent. Black galls may also be potential sources of biological control agents against decay-causing organisms in aspen.

Phoma etheridgei is described and illustrated from isolates obtained from the bark of black galls and cankers of trembling aspen in Alberta. Comparisons are made with Phoma enteroleuca and several other mostly wood-inhabiting Phoma spp. using morphological, physiological, and molecular characteristics. A key is provided for the differentiation of Phoma spp. that could potentially be isolated from Populus wood. Phoma etheridgei produced antifungal compounds that were strongly inhibitory in vitro to the aspen decay pathogen Phellinus tremulae on agar, in liquid media and on aspen wood chips, and may play a role in the natural ecosystem as an antagonist to Phellinus tremulae. Key words: Phoma etheridgei, taxonomy, black gall, antifungal metabolites, biological control, Phellinus tremulae, Populus tremuloides.

Isolates of the wood-decaying basidiomycete Phellinus tremulae were obtained from four different stands of aspen Populus tremula in the south of Sweden. Studies were made of somatic incompatibility among all isolated within each site. No genet could be found in more than one tree. From one stand, two trees were felled and samples were taken from stem discs every half metre up to 13 m. Eight genets were isolated from the two trees, four in each tree. Fungal DNA was amplified from five isolates representing three different genets in one tree. The core sequence of M13 was used as primer. The results agreed with those of the somatic incompatibility test. Forty-five samples were taken from small twigs from healthy-looking branches and trees, and isolates of Phellinus tremulae were obtained from three of them. The likely route of infection of Phellinus tremulae in aspen is discussed. Key words: somatic incompatibility, Phellinus tremulae, Populus tremula.

A series of new sesquiterpenes, the tremulanes, possessing a previously unreported substituted perhydroazulene carbon skeleton, has been isolated from liquid cultures of the aspen (Populus tremuloides) rotting fungus Phellinus tremulae. The structures were determined by NMR techniques ( 1 H- 1 H COSY, HMQC, and HMBC) and other physical methods including, in the case of tremulenolide A (6), X-ray crystallography. The chemical correlation of tremulenediol A (10) with tremulenolide A (6) is described as is the correlation of tremulenedial (8) with tremulenediol B (11). The absolute configuration of the compounds is assigned by application of the olefin octant rule to the allylic alcohol tremulenediol A (10). These new sesquiterpenes do not obey the biogenetic isoprene rule and it is suggested that they may not be derived from farnesyl pyrophosphate

The valence tautomer 2-carbomethoxyoxepin: 1-carbomethoxybenzene 1,2-oxide (1) has been isolated from liquid cultures of the wood-rotting fungus Phellinus tremulae. Methyl salicylate 2, a rearrangement product of the arene oxide 1, is produced by the same fungus. The biogenetic implications of these findings are discussed.

All over the world today is developing more and more the studies concerning biochemical and physiological features of mushrooms (macromycetes) in the view to promote them as biological tools in different types of biotechnologies grace of their bioabsorption capacity for biominerals, heavy, rare or noble metals. Generally the researches are focused on the elemental content of mushrooms (Barros, 2008; Jentschke, 2000; Krupa, 1997, 2004; Yamaca, 2007). This paper is about the level of bioabsorption for some heavy metals inside fruiting body, correlated to the substrate content and pH value. It is possible that one macromycetes species to contain in a high concentration one metal, but to have a low capacity of bioabsorption, the storage level being influenced by the substrate or environmental factors. This study aim is to establish the reality concerning the bioabsorption capacity for heavy metals of following six macromycetes species: Coprinus picaceus, Coprinus cinereus, Pseudotrametes gibbosa, Lyophyllum crassifolium, Paxillus involutus and Phellinus tremulae, grown in condition of natural pH of their substrate in a forestry ecosystem of Dambovita county in south of Romania. The elemental content of biological and environmental samples was determined by Atomic Absorption Spectrometry (AAS). So, maximum concentration of cobalt was find in fruiting body of Pseudotrametes gibbosa (0,1 ppm), minimum being at fruiting body of Coprinus cinereus (0,002). It was find nickel only in fruiting body of Phellinus tremulae and Pseudotrametes gibbosa.

A series of new sesquiterpenes, the tremulanes, possessing a previously unreported substituted perhydroazulene carbon skeleton, has been isolated from liquid cultures of the aspen (Populus tremuloides) rotting fungus Phellinus tremulae. The structures were determined by NMR techniques ( 1 H- 1 H COSY, HMQC, and HMBC) and other physical methods including, in the case of tremulenolide A (6), X-ray crystallography. The chemical correlation of tremulenediol A (10) with tremulenolide A (6) is described as is the correlation of tremulenedial (8) with tremulenediol B (11). The absolute configuration of the compounds is assigned by application of the olefin octant rule to the allylic alcohol tremulenediol A (10). These new sesquiterpenes do not obey the biogenetic isoprene rule and it is suggested that they may not be derived from farnesyl pyrophosphate

Ten volatile and sixteen non-volatile compounds have been isolated from culture filtrates of Peniophora polygonia. Among these, two volatile and three non-volatile compounds significantly inhibited in vitro growth of Phellinus tremulae.

Interactions between the two most common decay fungi of Populus tremuloides, Peniophora polygonia and Phellinus tremulae were studied. Pe. polygonia inhibited the growth of Ph. tremulae when grown in paired culture. The presence of a culture of Pe. polygonia reduced the growth of Ph. tremulae in a volatile metabolite test. A culture filtrate of Pe. polygonia reduced the growth of Ph. tremulae in liquid culture. The growth of both the fungi was inhibited, and they formed a dark brown line at contact point when grown on a Po. tremuloides block.

• In Quebec (Canada), predicting net merchantable volume of standing trees is essential to adjust stumpage fees. Furthermore, round-wood end use is important in the provincial forest management context because it is used to split the allowable annual cut among the different mill types. • A method relying on linear, binomial and cumulative logit regressions is proposed to predict both decay volume and round-wood end use volume. Tree age, height and quality, as well as ecological region, stand origin and presence of Phellinus tremulae (Bond.) Bond. & Boriss. and Ceratocystis fimbriata (Ellis & Halst.) fungi are the main factors that contribute to the presence and the proportion of decayed merchantable volume. Once the net merchantable volume is estimated, its division into round-wood end use is estimated through a series of steps involving the presence of Phellinus tremulae, saw log height, stem quality and size as explanatory variables. The first step is a multinomial regression which predicts the number of end uses (pulp wood, low-grade saw logs, saw logs, low-grade veneer, and veneer) that are present in the stem. A series of logistic regressions then determines the presence of each end use, with linear regressions predicting the round-wood volume of each end use.

In the spring of 1999, a long-term study was established to examine the physical and biological aspects of thinning young aspen stands in Minnesota. Three aspen stands ranging in age from 25 to 35 years were selected on lands owned by the State of Minnesota and UPM Kymmene. Two thinning treatments (low and high density) and an unthinned control were installed at each of the three locations. Permanent plots were installed to measure tree, shrub, and herb growth, and to monitor harvesting damage, insect and disease damage, soil strength, and fuel loadings. After 4 years, tree mortality was greater in the unthinned controls. Thinning treatment had no significant effect on the incidence of white trunk rot (Phellinus tremulae), Hypoxylon canker, or Saperda calcarata. No differences in post-harvest fuel loadings were detected among locations and treatments. Thinning increased the amount of light reaching the forest floor that resulted in greater herb and shrub biomass in the year immediately following thinning.

The effect of two stilbene compounds, pinosylvin and resveratrol, on the growth of several fungi was evaluated in plate tests. Wood decay tests were carried out with birch and aspen samples impregnated with the two stilbenes. In plate experiments, resveratrol had an enhancing effect on growth at concentrations where pinosylvin was already enough to prevent the growth of most fungi studied. Pinosylvin impregnated at 0.2% (w/w) concentration significantly reduced the decay caused by all fungi except Phellinus tremulae. In contrast, a resveratrol content of 0.8%, did not protect the wood from decay. A pinosylvin-synthase-encoding gene from Pinus sylvestris was transferred into aspen (Populus tremula) and two hybrid aspen clones (Populus tremula×tremuloides) by Agrobacterium tumefaciens-mediated transformation. Transgenic plants accumulated pinosylvin synthase-specific mRNA and showed stilbene synthase enzyme activity in vitro. Transgenic aspen line H4 showed increased resistance to Phellinus tremulae, while two hybrid aspen transformants decayed faster than the control trees. However, we were unable to detect the accumulation of stilbenes in the transgenic plantlets.

Large, black perennial trunk galls occur on trembling aspen (Populus tremuloides) in localized areas of Alberta and British Columbia. The cause of many of these galls is unknown, but some galled trees have been previously shown to be less likely to have advanced decay caused by Phellinus tremulae than are surrounding nongalled trees. In a large area of trees with multiple stem galls near Dawson Creek, British Columbia, the surface morphology of galls differed from that of galls occurring in central Alberta. The Dawson Creek galls had succulent red tissue proliferations on the surface that contained poplar budgall mites (Aceria parapopuli), which normally occur on aspen twigs, but rarely on stems. The trees in this study appear to be of one clone and, from examination of the internal gall morphology, have likely been continuously inhabited by mites for many years. The potential of these mites to induce resistance against decay needs further study.

Chemical investigation of the metabolites produced when a new fungus, Hyphozyma lignicola, isolated from blackgalls on aspen, was grown in malt extract liquid medium resulted in the isolation and identification of five trehalose esters 1-5, which are unusual fungal metabolites. The major compound is 3,6-di-O-acetyl-2-O-octadecanoyl-alpha,alpha-D-trehalose [2]. The structures were established by the analysis of nmr and fabms data in combination with chemical degradation.

Phellinus tremulae was inoculated on Populus tremula. It spread in the sapwood and inner wood of a living tree without other organisms being present. Plating experiments with wood meal from different parts of a sound tree showed that there were very few, if any, propagules of micro organisms in the sound wood, neither were there any organisms found in front of the decay of P. tremulae at the top of the decay column. These results support the theory that P. tremulae is a primary parasite in aspen. Decay fungi grown on fresh and autoclaved wood of aspen had very different growth rates. Most of the fungi tested grew best on autoclaved sapvvood. The difference in growth rate on fresh and autoclaved heartwood was lcss significant, suggesting that there is a barrier in the living wood which is destroyed by autoclaving. P. tremulae was thc only fungus that grew best on fresh inner wood.

SUMMARY Phenoloxidase and peroxidase were extracted from pigmented zones (zone lines) which were formed on agar media between two Phellinus weirii isolates or by one P. weirii isolate in response to the presence of an antagonist. Activity of enzymes from zone lines was compared with that of enzymes from mycelial tissues adjacent to the zone lines by isoelectric focusing on polyacrylamide gels. Zone lines produced stronger phenoloxidase and peroxidase reactions than did adjacent tissues. At least three phenoloxidases and as many as six peroxidase isozymes were detected in zone lines, some of which may have been induced or caused by the antagonists. Phenoloxidase and peroxidase were observed also in the zone lines formed by P. weirii in colonized Douglas-fir wood, but not in adjacent tissues. Phellinus weirii (Murr.) Gilbertson is a destructive root pathogen of conifers in northwestern United States and southwestern Canada. In cultures, confronted isolates of this fungus from separate infection centers develop a darkly pigmented zone line at their interface. The zone line is a distinct narrow dark line, representing a sheet of fungal mycelium composed of characteristic swollen hyphal cells. Childs (1963), who first recorded the phenomenon in P. weirii, used the term 'line of demarcation' and called the paired isolates forming these lines "clones" of the species. Pigmented zone lines also can be formed by P. weirii on agar media or in P. weirii-colonized wood in response to some antagonistic microorganisms. Zone lines appear to enhance P. weirii survival in colonized wood by excluding antagonists (Nelson, 1964, 1975). Kuwana (1958) found that cell fusion between different strains of Neurospora crassa Shear and Dodge that normally do not produce phenoloxidases leads to induced phenoloxidase activity and pigment formation. Hiroth (1965) reported that interactions at the interface between different isolates of Phellinus tremulae (Bond.) Bond. et Boriss, resulted in induction of weak phenoloxidase activity and pigment

The number and stem position of three endemic disease- and insect-caused injuries, shoot dieback, galls, and lesions, were monitored during the first 7 years of development of aspen (Populustremuloides Michx.) sucker stands on both a good and an excellent site. Injury frequency was significantly higher on the good site compared with the excellent site. Only shoot dieback clearly had a negative effect on height growth and tree class differentiation. Galls and lesions were related directly to bole area but not tree class. These injuries healed rapidly and most were undetectable within a few years. The apparently high incidence of insect- and disease-induced injury is normal in aspen sucker stands. Tree mortality was caused by intraspecific suppression and was not enhanced by any of these injuries. Although growth is undoubtedly diminished owing to injury, productivity of these stands should meet or exceed historical expectations. The effect of site quality, stocking density, and other stand variables on the influence of insect- and disease-induced injury needs controlled experimentation to assess their roles in affecting aspen productivity.

In contrast to the woodrotting fungi which can only attack Populus tremula after felling, Phellinus tremulae successfully invades the central part of the living tree. Possible causes for this difference were investigated. It was found that sterile wood samples were decomposed more rapidly by saprophytic fungi than by parasitic fungi. With both types of fungi, heartwood was more resistant to decay than sapwood. It is postulated that living sapwood inhibits infection by most woodrotting fungi, but that P. tremulae can successfully overcome this barrier. This postulate cannot be confirmed by experiments using sterilized wood samples.

The distribution of Phellinus tremulae in stems of Populus tremula was studied visually, macroscopically as well as microscopically, and by means of isolation of the fungus in pure culture. Evidence suggests that P. tremulae occurs alone in most of the tree. Microorganisms associated with P. tremulae in the wood are suggested to be independent invaders or secondary invaders. A dark reaction zone was formed in certain parts of the wood and consisted microscopically of melanized hyphes and brown material in the ray cells. An inner wood, formed as a result of the death of nearby brandies, is apparently the main part infected by P. tremulae, and its outer border may basically limit the spread of the fungus in the trunk. The formation of “heartwood” in aspen is discussed, and a suggested outline shown for the infection and decay processes caused by the fungus.