Search

Isolates that resemble Dothiorella (Botryosphaeriaceae, Ascomycota) species were isolated from dead twigs, asymptomatic and necrotized bark of European hop hornbeam (Ostrya carpinifolia Scop.), Eurasian smoke tree (Cotinus coggygria Scop.) and common juniper (Juniperus communis L.) growing in western Slovenia and northern Italy. They were identified based on anamorph morphology and phylogenetic analyses of the ITS rDNA and EF-1α sequences, and previously designated as Dothiorella sp. A, B and C. This study has clarified the identity of these species by comparing them with other Dothiorella species known from culture based on gene sequence data, as well as morphological characters of the anamorphs. The phylogenetic results revealed three species, Dothiorella iberica, Dothiorella parva, and a Dothiorella sp. Isolates identified in the phylogenetic analyses as D. parva differed from the original description of this species and are thus described here based on the anamorph morphology. Isolates of D. parva were identified from O. carpinifolia in western Slovenia and northern Italy, and C. coggygria in western Slovenia, and coexist with Dothiorella sp. on O. carpinifolia in northern Italy. Dothiorella iberica was identified on J. communis in western Slovenia, thus expanding the geographic range of this species. This is the first record of D. parva from these hosts and countries. Our results indicate that these Dothiorella species occur widely across the Mediterranean region, and on a variety of hosts. [ABSTRACT FROM AUTHOR]

Eurypelici pcircisitica was recently reported in Europe for the first time, and this study reports the molecular evaluation of the internal transcribed spacer (ITS)l/5.8S/ITS2 regions of 68 isolates of the fungus obtained in pure culture with polymerase chain reaction restriction fragment length polymorphism (RFLP). The RFLP patterns of all isolates proved identical and the restriction profiles served to differentiate E. parasitica from Eulypa lata, another pathogenic member of the family Diatrypaceae. Low intraspecific variability was detected in the sequenced ITS 1/5.8S/ ITS2 regions of eight Eutypella parasitica isolates originating from different hosts and geographical locations. Based on this ITS region, EpR/F primers specific to E. parasitica were constructed and tested with a wide range of fungal isolates. The EpRIF primer pair successfully amplified the expected fragment size of 341 bp from isolates of E. parasitica and also directly from infected maple wood shavings. The RFLP patterns and species-specific primers represent a step toward routine, large-scale, and rapid molecular diagnostics and identification of E. parasitica. [ABSTRACT FROM AUTHOR]

Ash dieback is caused by a highly pathogenic fungus Hymenoscyphus pseudoalbidus (anamorph Chalara fraxinea). Possibilities for disease control are limited, and treatment of fallen leaf debris to prevent sporulation of the pathogen is one of the possible options to control the disease. In some cases chemical treatments could be used, but data on effective chemical agents for control of the ash dieback are lacking. The purpose of this study was to examine the effect of different chemical fungicides and urea on the pathogen. Out of eight tested fungicides, mycelial growth in Petri plates as well as development of H. pseudoalbidus apothecia on ash leaf petioles were most efficiently inhibited by carbendazim. Urea also proved to be effective in prevention of apothecial formation. In addition to inhibition of the pathogen, urea accelerates the degradation of treated leaf debris. Therefore, the use of urea for treatment of infected ash leaf debris could be more effective than the use of fungicides and also more environmentally acceptable. [ABSTRACT FROM AUTHOR]

The attractiveness of different semio-chemicals to potential vectors of the phytoparasitic nematode Bursaphelenchus xylophilus was investigated in conifer forests in Slovenia. From 2007 to 2009, the presence of xylophagous beetles in Pinus nigra, P. sylvestris, P. halepensis, Picea abies and Abies alba stands was assessed at eight locations. Insects were collected at 1-month intervals during the growing season using four cross vane traps per location with a collecting container with propylene glycol and attractants (ethanol+α-pinene, Pheroprax® and Gallowit®). The trapped insects represented 24 families of the order Coleoptera, and we identified 94 species. The most numerous group was the weevil subfamily Scolytinae (76.55% of all insects collected), followed by the family Cerambycidae (8.12%), and the weevil subfamily Curculioninae (1.67%). With regard to species number, the most frequent wood-borers were Cerambycidae (24 taxa), Scolytinae (12 species) and Buprestidae (8 species). The most abundant species was Spondylis buprestoides, followed by Arhopalus rusticus, Monochamus galloprovincialis and Arhopalus ferus. At all locations, the largest catch of Cerambycidae occurred in July. The most effective attractant was ethanol+α-pinene, followed by Gallowit®; the least effective attractant was Pheroprax®. Among Monochamus species, M. galloprovincialis represented 17.54%, M. sutor 0.09% and M. sartor 0.04% of the long-horned beetles collected. Monochamus individuals were most numerous in the P. nigra stand and were attracted in the greatest numbers by Gallowit®, followed by ethanol+α-pinene. The cerambycid catch was highly correlated with the catch of non-target bark beetle predators (Cleridae, Staphylinidae, Histeridae, Trogositidae, Nitidulidae, Rhizophagidae) in the traps. [ABSTRACT FROM AUTHOR]

Abstract: The influence of Pleurotus ostreatus inoculation on wood degradation and on fungal community structure was studied. The experiments were performed on an organically poor fly ash deposit covered with a 10cm layer of beech wood chips inoculated with P. ostreatus isolate ZIM76. Compared to non-inoculated wood chips, inoculation increased the temperatures and relative humidities and, in the first 6months, accelerated Klason lignin degradation by 9% and also, after 17months, increased iron translocation into wood chips by 30%. After 6months, PCR–DGGE showed 22–28 and 13–21 fungal taxa in non-inoculated and P. ostreatus-inoculated beech chips, respectively. The differences in number of taxa and in the fungal community structure (based on Dice coefficient) between non-inoculated and inoculated wood chips diminished with time. The results indicate that the naturally occurring processes of wood degradation are as efficient as those occurring in sites inoculated with P. ostreatus. [Copyright &y& Elsevier]

Unusual and extensive dieback of European hop hornbeam ( Ostrya carpinifolia) has been observed in western Slovenia and northern Italy in recent years, when extreme drought and higher temperatures were recorded. A preliminary study identified Botryosphaeria dothidea as a potential causative agent of the dieback. Further characterization of intra- and interspecies diversity of Botryosphaeriaceae collected from O. carpinifolia and other tree species in the affected area was achieved based on anamorph morphology, sequence data from the ITS rDNA and EF1-α, PCR-RFLP analysis and AFLP profiles. The majority of the isolates analyzed were identified as B. dothidea, and in vitro pathogenicity tests re-confirmed the fungus to be an important cause of the disease. Insight into the B. dothidea population, diversity based on AFLP markers indicates that the dieback observed in O. carpinifolia is probably associated with a heterogenous population of B. dothidea, which emerged from a latent state in response to changed climate conditions. Isolates with Dothiorella-like conidia were also identified during the survey, but these were collected more rarely and appear to represent undescribed species. Isolates from Dothiorella genus expressed low pathogenicity in pathogenicity tests and proved no impact on the pathogenic ability of B. dothidea. [ABSTRACT FROM AUTHOR]

Abstract: A mycoremediation system of wood substrate and fungal inoculum was established on an organically poor fly ash deposit at the Šoštanj Thermal Power Plant, Slovenia. A mini-block method with beech wood samples was used to select a suitable fungal isolate for inoculation into the mycoremediation system. Pleurotus ostreatus ZIM 76 proved to be the most appropriate for further tests. Compared to the mass loss in a non-contaminated medium, wood degradation with the selected fungal isolate was reduced by 51% on wood substrate contaminated with 17% (w/w) fly ash. The deterioration processes of wood chips on inoculated and non-inoculated experimental plots were studied by ionic chromatographic analyses of volatile organic acids in water extracts. The presence of P. ostreatus did not influence the concentrations of acetic and formic acids in water extracts from wood chips collected at experimental plots in different intervals from May 2006 to November 2007 comparing inoculated vs. non-inoculated plots. [Copyright &y& Elsevier]