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A total of 57 naturally established Stereum sanguinolentum isolates was obtained from artificially wounded Picea abies stems in a forest area of 2 ha in Lithuania. Somatic incompatibility tests revealed 27 vegetative compatibility groups (VCGs) that contained 1â10 isolates. There was no spatial clustering of S. sanguinolentum VCGs within the forest area. The extent of S. sanguinolentum decay was analysed in 48 P. abies stems, 9â26 cm in diameter at breast height. Within 7 years of wounding, the length of S. sanguinolentum decay column in stems was 107â415 cm (291.5 ± 77.3 cm on average), lateral spread of the fungus at the butt was 38â307 cm2 (142.3 ± 66.8 cm2) and decayed proportion of the stem cross-section at the wound site (the butt) was 3â84% (36.8 ± 19.7%). In average, S. sanguinolentum VCG that infected 10 trees exhibited more slow growth inside the stem than VCGs that infected only one tree, and vertical growth varied to a greater extent within this VCG than among different VCGs. Correlation between stem diameter and vertical spread of S. sanguinolentum was not significant (r = â0.103). Despite uniformity of debarked area on all stems 7 years ago (300 cm2), open wound sizes on individual trees at the time of study were between 97â355 cm2 (215.1 ± 59.2 cm2) indicating large differences in wound healing capacity.

Stem bases of 210 Fraxinus excelsior trees of three different health categories were sampled by the means of an increment borer in declining ash stands in northern Lithuania. From this number, 15 sound-looking, 132 declining and 63 dead trees from three discrete plots yielded 352 isolates, representing 75 fungal species. In addition, mycelial fans and rhizomorphs typical of Armillaria spp. from 205 and 20 trees, respectively, were sampled and subjected to fungal isolations. Species richness was similar in trees from each health category, but community structures differed, indicating that species composition of wood-inhabiting fungi in stems changes along with the changes in tree health condition. Armillaria cepistipes was the most common species (86 isolates from 210 wood samples, or 41.0%), isolated more frequently and consistently than any other potential tree pathogen. It also showed abundant occurrence on a majority of trees in the form of mycelial fans and rhizomorphs, from which 64 and 14 isolates of the fungus were obtained, respectively. The population structure of A. cepistipes revealed the presence of 53–93 genets per hectare, some of which extended up to 30–55  m. [ABSTRACT FROM AUTHOR]

One possible option to avoid infections of the root rot fungus Heterobasidion annosum s.s. in plantations of Pinus sylvestris is to thin as few times and as late as possible. For this purpose, experimental plantations of P. sylvestris were established on former agricultural land in central Lithuania, where pine seedlings had been sparsely planted in different mixture schemes with the deciduous species Robinia pseudoacacia, Amorpha fruticosa and Betula pendula. As a control, two plantations of pure P. sylvestris were established at the same site in different densities. We estimated tree and stand characteristics in the experimental plantations at the age of 25 years and identified the community of wood-inhabiting fungi. No infection of H. annosum s.s. was found. The results showed that intercropping allows delayed thinnings and a better economical result could be obtained in mixed than in pure pine stands. Crown width and stem taper of the individual trees, however, were negatively affected by the wide spacing, but still remaining acceptable from a silvicultural point of view. The fungal flora differed between externally healthy and declining pines within a forest site. Higher mycodiversity was revealed in wood of declining trees. [Copyright &y& Elsevier]

The availability of coarse woody debris (CWD) and distribution of dead trees into categories of mortality (dead standing, broken and uprooted) were investigated in north-temperate forests of central Europe (Lithuania). The studied area comprised 188.7 ha and included 18 different stands 40–130 years of age with a variety of tree species (spruce (Picea abies (L.) Karst.), pine (Pinus sylvestris L.), alder (Alnus glutinosa (L.) Gaertn.), birch (Betula pendula Roth and B. pubescens Ehrh.), aspen (Populus tremula L.), oak (Quercus robur L.), forest types (caricus-sphagnum, vaccinium-myrtillus, oxalis, myrtillus-oxalis, caricus-calamagrostis) and edaphic conditions (peaty, sandy, loamy soils of different moisture). The stands were excluded from wood harvesting for at least 30 years. A total of 11 365 dead trees (over 10 cm in DBH) or 6160.7 m3 of dead wood was found (60.2 trees/ha and 32.6 m3/ha). The volume of CWD per hectare was larger in older stands (rS=0.78, P<0.01). Tree mortality during the last 2 years consisted of 482 trees and 381 m3, or 1.28 trees/ha×year and 1.01 m3/ha×year. In 25–33% of cases it was wind-related. Uprooted and broken trees were of larger DBH than dead standing. The distribution into the categories of mortality was strongly dependent on tree species (chi-square test, d.f.=10,P=0). Dead standing dominated in CWD of pine and alder. Broken trees comprised almost a half in CWD of aspen, and about one-third in birch, alder and oak. Uprooting most often occurred in spruce, aspen and birch. Edaphic conditions and stand age had a pronounced impact on distribution into mortality categories for spruce (chi-square test, d.f.=20, P<0.00001) and pine (d.f.=8, P≤0.0003). On peat soil, only a minority of trees of both pine and spruce was uprooted, and standing dead prevailed. In CWD of spruce and pine, the proportions of both dead standing and broken decreased and that of uprooted trees increased on mineral soils of higher moisture and bulk density in older stands. By contrast, uprooting in birch and alder occurred less often on more wet sites, where the proportions of standing snags were higher. A total of 41 species of wood-decomposing polypores were found in the study area. Among those, 10 (24%) were of conservation value. [Copyright &y& Elsevier]

The community of Aphyllophorales fungi in stumps of Picea abies (L.) Karst. and the occurrence of root rot caused by Heterobasidion annosum were investigated at 38 clear-felled sites in Lithuania. Fruit-bodies were recorded on 36.0% of the 3924 examined stumps. The most common were Bjerkandera adusta, Phlebiopsis gigantea, Fomitopsis pinicola, Gloeophyllum sepiarium, Stereum sanguinolentum, Trametes zonata and H. annosum. All species occurred in stumps both with and without established root rot, but B. adusta, F. pinicola, G. sepiarium, T. zonata and Trichaptum abietinum occurred less often in stumps containing root rot, while H. annosum was encountered more often. Greater numbers of fruit-bodies were found on stumps cut in summer than on those cut in winter. The fruiting became most abundant 3-4 yrs after the trees were felled. The abundance of nearly all Aphyllophorales correlated positively with the stump diameter, and on larger stumps, fruit-bodies of several different fungi were more common. The number of stumps containing H. annosum root rot in different sites varied from 9.8% to 68.8%, and was 27.6% on average. The incidence of root rot correlated neither with the age nor with the density of the felled stand, but it correlated negatively with the proportion of deciduous trees within a stand. [ABSTRACT FROM AUTHOR]

Genetic variation within and between vegetative compatibility groups (VCGs) of Amylostereum areolatum (Fr.) Boid, and Amylostereum chailleteii (Pers.: Fr.) Boid, isolates was investigated DNA fingerprints were made using the M13 core sequence as a primer. A total of 53 isolates of A. arelatum and 57 isolates of A. chailletii from Lithuania, Sweden, Denmark and Great Britain were studied. In all cases isolates belonging to the same VCG showed identicle DNA banding patterns, suggesting that VCGs correspond to clones. In A. areolatum the vast majority of the isolates (spread by Sirex juvencus L.) were assingned to despersive clones that have wide geographical distribution (i.e. the same genotypes were detected in Lithuania, Sweden and Denmark), with low genetic variation between the different clones. By contrast, A. chailletii population structure was consistent with the spread of airborne basidospores produced by outcrossing. Only a small fraction of A. chailletii isolates studied, could be assigned to dispersal clones with a local distribution, spread by Urocerus gigas L. Overall, M13 fingerprinting detected low genetic differentiation in both species in the samples we studied. [ABSTRACT FROM AUTHOR]

Investigates wood inhabiting fungi in a forest stand of Picea abies damaged during selective cutting and bark peeling in Lithuania. Common fungi infecting wound; Species composition of wood inhabiting fungi in stands; Stem analysis.

Seven polymorphic microsatellite markers were developed for the wood-decay basidiomycete Phlebia centrifuga. The primers were identified using two techniques, based on intersimple sequence repeats (ISSR) and amplified fragment length polymorphism (AFLP), respectively. The markers were screened on 27 isolates from Europe and North America. Two markers varied only on a worldwide scale, but not within Europe. The other five showed variation on both scales. These markers will now be used to characterize populations of P. centrifuga, which is red-listed as near-threatened in its natural habitat due to human disturbance. [ABSTRACT FROM AUTHOR]

Bioassay-guided fractionation of culture supernatants of the actinomycete Kutzneria sp. 744 resulted in the isolation of four new depsipeptides (1-4). Structure analysis revealed the general structure: cyclo[2-(1-methylcyclopropyl)-D-glycine-(2S,3aR,8aS)-6,7-dichloro-3a-hydroxy-1,2,3,3a,8,8a-hexahydropyrrolo[2,3-b]indole-2-carboxylic acid-3-hydroxy-D-glutamic acid-O-methyl-L-serine-L-piperazic acid-(S)-2-hydroxy-3,3-dimethylbutanoic acid]. The 3-hydroxy-d-glutamic acid was present as its threo-isomer in 1 and 2 and as its erythro-isomer in 3 and 4. The piperazic acid was modified to its (R)-4-chloro analogue in 2 and to its C-5/N unsaturated analogue in 4. Compounds 1-4 displayed moderate spore germination inhibiting activity against several common root-rotting fungi.