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Six new C12 polyketides, phomretones A–F (1–6), were isolated from the co-culture of Armillaria sp. and the endophytic fungus Phoma sp. YUD17001 associated with Gastrodia elata. Neither fungus produced these compounds when cultured alone. The structures of 1–6 were established on the basis of comprehensive spectroscopic analyses, while their absolute configurations were determined by the comparsion of experimental and calculated ECD spectra. Compounds 2–4 are diastereoisomers of each other and featured high levels of stereoisomerization and oxidation.

Three novel polyoxygenated meroterpenoids, epiterenoids A–C (1–3), and a new illudalane derivative, armiloid A (4), were isolated from a liquid co-culture of Armillaria sp. and the endophytic fungus Epicoccum sp. YUD17002 associated with Gastrodia elata. Their structures were established by extensive spectroscopic analyses, X-ray crystal diffraction, and TDDFT-ECD calculations. Compounds 1–3 possessed a 5/6/4/5/5-fused pentacyclic ring scaffold. Plausible biosynthetic pathways for 1–4 are proposed. Compound 4 exhibited potent AChE inhibitory activity, with an IC50 value of 4.91 μM.

Two new compounds, 10-dehydroxymelleolide D (1) and 13-hydroxymelleolide K (2), along with seven known compounds, 5'-O-methylmelledonal (3), melleolide D (4), 13-hydroxydihydromelleolide (5), melleolide (6), armillarinin (7), armillaridin (8), and armillarikin (9), were isolated from the culture broth of Armillaria sp. Their structures were determined by spectroscopic data analysis. All the compounds inhibited plant growth of lettuce. Melleolide (6) and armillarikin (9) inhibited mycelial growth of Coprinopsis cinerea and/or Flammulina velutipes.

Varem tehtud teadustöödes on leitud, et erinevat liiki ürasklased (Scolydinae) levitavad mitmeid olulisi puittaimede seenpatogeene. Tunduvalt vähem on seenpatogeenide levitajatena uuritud männikärsakaid (Hylobius sp.). Kasutades kaasaegseid bioinformaatilisi meetodeid, määrati seenekooslused nii putukkahjurite kui ka puittaimede proovidest. Seenekooslused määrati seente rDNA ITS2 järjestuste alusel. Töö tulemusena määrati kahjurputukate proovidest puidusinetust põhjustavaid seenpatogeene nagu Ophiostoma sp., Ceratocystis sp. ja Pesotum sp., juuremädanikku põhjustavaid külmaseeni (Armillaria sp.) ja juurepessu (Heterobasidion spp.), ning taimede seenpatogeene nagu Neonectria sp., Phoma herbarium, Peniophora limitata, Pyrenochaeta cava ja Phaeoacremonium hungaricum.

In the control of the fungus Heterobasidion annosum the most frequently applied method is stump treatment with biological preparations containing dehydrated spores of the saprophytic fungus Phlebiopsis gigantea (syn. Peniophora gigantea /Fr./ Massee). In the field, this fungus is a competitor to the fungus Heterobasidion annosum. This paper presents the results of laboratory analyses of interactions of decay fungi isolated from the root and butt of uprooted spruce trees in the Nature Park "Stara Planina", and their relation to the fungus Ph. gigantea. The interactions of these fungi were analyzed at the temperatures of 20?C, 25?C and 30?C.

Three novel compounds were isolated from the culture broth of Armillaria sp. Their structures were elucidated mainly by spectroscopic data analyses. All the compounds regulated hypocotyl and root growth of lettuce.

The paper proposes a method of assessing the potential risks of the future development of stands in relation to a climatic change. To assess risks of the future development of a stand simple point scales have been worked up based on primary properties of a site and a stand according to data of the forest management plan (FMP). In assessing the health condition, the risk of damage to stands by Armillaria sp. in the felling age was evaluated on the basis of a present attack by Armillaria sp. and also defoliation of the crown primary structure assessed during a simple field examination. The evaluation was carried out in the re - gion of the Křtiny Training Forest Enterprise (TFE) Masarykův les, ranger district Proklest, in 2002. The study was conducted in 118 Norway spruce stands aged more than 20 years. The majority of evaluated stands ranked among the category of high and medium risk from the viewpoint of site and stand risks and among the category of high Armillaria sp. attack.

Three novel lettuce hypocotyl and root growth regulating compounds, armillariols A (I), B (II), and C (III), are isolated from the culture broth of Armillaria sp.

Investigations on water relations of spruce infested by Armillaria sp.Picea omorika and Picea abies intested by Armillaria sp. showed increased osmotical potential and reduced water content in the needles compared with not infested controls. The transpiration flow rates decreased with increasing infestation. Inserting grafts from mother trees, damaged by Armillaria, in healthy stock led to normal development of the grafts without disease to the stock.

The frequency and degree of aspen stump colonization by undetermined Armillaria sp. was quantified by examination of 185 bulldozed stumps in two Wisconsin aspen stands, 2or5 years after cutting. Rhizomorphs were associated with all stumps examined. All of the 5-year-old stumps and 94 % of the 2-year-old stumps were colonized. Armillaria had colonized >50 % of the root-collar area of 98 % of the 5-year-old stumps, but only of 13 % of the 2-year-old stumps. Mycehal fans and decay extended from stumps into roots.

A armilariose tem sido considerada a principal doença em Pinus no Brasil. Os sintomas e danos consistem no amarelecimento de acículas, declínio, podridão de raízes, exsudação de resina e morte. A temperatura é um dos fatores ambientais que influencia patógenos, doença de plantas ou ambos. Este trabalho avaliou o comportamento de três isolados de Armillaria sp. obtidos de P. elliottii var. elliottii, submetidos a uma faixa de temperatura de 16 a 26 ºC, utilizando a biomassa seca produzida em meio líquido como parâmetro de análise. Verificou-se que todos os isolados apresentaram máxima produção de biomassa a 22 ºC. Utilizando-se de regressão cúbica encontrou-se temperaturas de máximo crescimento entre 21,79 e 23,19 ºC. De acordo com os resultados, a melhor temperatura para crescimento dos isolados testados situou-se em 22 ºC. Armillaria root rot is the major pine disease in Brazil. Symptoms of this disease are yellowing of the needles, decline, root rot, resin exsudation and plant death. Temperature is an environmental factor that affects pathogens, the disease or both. This work evaluated the behaviour of three isolates of Armillaria sp. obtained from P. elliottii var. elliottii. The fungus isolates were submitted to temperature ranging from 16 to 26 ºC, by using dry biomass production in liquid medium as a measureable variable. All isolates produced higher amount of biomass at 22 ºC. A cubic regression showed a maximum point of temperatures between 21,8 e 23,2 ºC. The best temperature for fungus isolates growth was around 22 ºC.

SUMMARY ‘Regrowth dieback’, a disease of Eucalyptus obliqua and E. regnans is causing serious degradation of high yield, even-aged, regrowth forest in south-eastern Tasmania. Dieback symptoms in crowns of diseased trees were first observed in the region in 1964 and since then the disease has continued to develop. Visual symptoms of the disease can be discerned only in crowns of dominant and co-dominant trees since sub-dominant and suppressed trees show similar symptoms due to normal stand competition. This work shows that for increment periods which finished in 1958 or earlier, basal area increments of dominant and co-dominant trees from a number of growth plots in the region were slightly lower in trees which were affected by the disease in 1971 than in those which were not. There were much larger reductions in increments of affected trees measured in increment periods which finished in 1960 or later. It was concluded that an agent very damaging to forest health appeared in the region in 1959 or early 1960. This coincides with the start of a period of several years of unusually dry summers in the region. These findings conform with an earlier suggestion that the disease may have been initiated by drought with secondary damage by the root-rotting fungus Armillaria sp. and/or the defoliating beetle Chrysophtharta bimaculata. The fungus is ubiquitous in the region and has frequently been associated with decayed roots of affected trees. The beetle is believed to have caused episodic tree defoliation in the region. It is suggested that the secondary agents normally cause death or ill-health of a few trees in otherwise healthy forest. Physiological weakening of trees by drought may have allowed the effects of these agents to increase substantially after 1959.

Three new sesquiterpene aryl esters, named 10-dehydroxy-melleoliede B (1), 1-O-formyl-10-dehydroxy-melleoliede B (2) and 10-oxo-melleoliede B (3) together with six known ones (4–9), were isolated from the cultures of Armillaria sp. The structures of the new compounds were elucidated based on the extensive spectroscopic methods. Compounds 1, 2, and 5–9 exhibited moderate cytotoxicities.