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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,3aSM8aS)-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.

Fungi colonising root tips of Pinus sylvestrisand Picea abiesgrown under four different seedling cultivation systems were assessed by morphotyping, direct sequencing and isolation methods. Roots were morphotyped using two approaches: (1) 10% of the whole root system from 30 seedlings of each species and (2) 20 randomly selected tips per plant from 300 seedlings of each species. The first approach yielded 15 morphotypes, the second yielded 27, including 18 new morphotypes. The overall community consisted of 33 morphotypes. The level of mycorrhizal colonisation of roots determined by each approach was about 50%. The cultivation system had a marked effect on the level of mycorrhizal colonisation. In pine, the highest level of colonisation (48%) was observed in bare-root systems, while in spruce, colonisation was highest in polyethylene rolls (71%). Direct internal transcribed spacer ribosomal DNA sequencing and isolation detected a total of 93 fungal taxa, including 27 mycorrhizal. A total of 71 (76.3%) fungi were identified at least to a genus level. The overlap between the two methods was low. Only 13 (13.9%) of taxa were both sequenced and isolated, 47 (50.5%) were detected exclusively by sequencing and 33 (35.5%) exclusively by isolation. All isolated mycorrhizal fungi were also detected by direct sequencing. Characteristic mycorrhizas were Phialophora finlandia, Amphinema byssoides, Rhizopogon rubescens, Suillus luteusand Thelephora terrestris. There was a moderate similarity in mycorrhizal communities between pine and spruce and among different cultivation systems.

The aim of the present work was to investigate the potential for territorial and dispersive clonality in natural populations of the postfire root rot ascomycete Rhizina undulata.Population studies based on vegetative compatibility tests were done with strains isolated from individual sporocarps at five burned sites in three different localities (separated by 20–40 km) in the Curronian Spit of western Lithuania. Among a total of 103 strains, the tests identified 14 distinct vegetative compatibility groups (VCGs) of R. undulata,13 of which were represented by 2–48 strains and three were encountered at 2–4 different sites. Occurrence on spatially separated sites of the same VCG of the fungus indicated a presence of dispersive clonality in R. undulatapopulations. On a local scale clusters of vegetative compatible sporocarps usually occupied discrete territories, implying territorial clonality. The two largest VCGs covered areas up to 7 and 3 m across. The results show that both dispersive and territorial clones are characteristics of natural populations of the fungus.

AbstractThe mating system of the postfire ascomycete Rhizina undulatawas investigated. Five fruit-bodies of the fungus were collected from three different sites in western Lithuania. Pure cultures were obtained both from the fruit-bodies and from single ascospores. Mycelia were paired on Petri dishes in all possible combinations. Complete intermingling was noted in all pairings among single ascospore isolates and mycelium from the same fruit-body, and from three different fruit-bodies from the same locality. Demarcation zones were noted in pairings among single ascospore isolates and fruit-body mycelia from different localities. Amplified DNA patterns within ascospore families and among families within the same locality were identical or nearly identical. Single ascospore isolates of R. undulataformed fruit-bodies in vitro, although ascospore production was not observed. Thus, R. undulatais reported to be homothallic. The possibilities are discussed both for dispersive and territorial clonality in its natural populations.

Mycelial interactions were studied between 28 isolates of Amylostereum areolatum and 15 of A. chailletii from wounded spruce in 10 sample plots in Sweden and Lithuania. Based on somatic incompatibility, nine vegetative compatibility groups (VCGs) of A. areolatum were detected. Five of these VCGs were isolated from two or more trees and included 24 (86%) of all isolates. In A. chailletii, 12 VCGs were found and three contained two isolates each. Grouping of isolates into VCGs was more pronounced in A. areolatum. Two of the A. areolatum VCGs had wide geographical distribution. VCG A2 was isolated from 14 different trees in two Swedish and four Lithuanian sample plots. VCG A1 was found in one plot in Sweden and in two in Lithuania. VCGs of A. chailletii had a local distribution and were confined to a single sample plot or to a forest stand. In A. areolatum occurrence of compatible pairings between isolates was uniform in all spatial scales of investigation: within a plot, within each country and among both countries. The proportion of somatically compatible A. chailletii isolates was significantly lower and decreased with geographic distance.

A total of 34 isolates of Cylindrobasidium evolvens were obtained from wounded Picea abies in five sample plots in Sweden and Lithuania. Population structure and genetic variation within the species were assessed by somatic incompatibility and arbitrary primed DNA (AP-DNA) analysis, using the M13 core sequence as a primer. All somatic incompatibility pairings between different C. evolvens isolates resulted in weak mycelial antagonism. The AP-DNA profiles indicate genetic variation was high in the species with no differentiation among isolates being found either on a large (more than 700 km) (R2=0·108) or a fine scale (200 m) (R2=0·024). In a plot, genetic similarity was significantly higher (P<0·02) among isolates from wounds infected during the previous 2 years than among the rest of the same population.