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Papers by Alexander Urban
Phyton-annales Rei Botanicae, Jul 25, 2000
Mycological Progress, 2022
Three little known, morphologically similar species of Sclerotiniaceae which form their apothecia... more Three little known, morphologically similar species of Sclerotiniaceae which form their apothecia on fallen stromatized Veronica seeds are described and illustrated in detail based on fresh collections or moist chamber cultures of infected seeds: Ciboria ploettneriana, Schroeteria decaisneana, and Schroeteria poeltii. The former two were found on Veronica hederifolia agg. at different sites of temperate central Europe, the latter on V. cymbalaria in a mediterranean region of Spain. The latter two are anamorph-typi ed and here reported for the rst time with their teleomorph. Ciboria ploettneriana was described by Kirschstein as Sclerotiniaploettneriana on seeds of V. hederifolia agg. but is currently treated in Ciboria. Based on the reexamination of four syntype specimens in B it became evident that Kirschstein confused the two species on V. hederifolia. A lectotype is therefore designated for S. ploettneriana. Members of Schroeteria are speci c plant parasites infecting fruits of different Veronica spp. Schroeteria has earlier been referred to the Ustilaginales (Basidiomycota) based on its smut-like chlamydospores, but later light-microscopic and ultrastructural studies suggested that it represents a false smut fungus belonging to the Sclerotiniaceae (Helotiales). rDNA sequences were obtained from chlamydospores of Schroeteria bornmuelleri (on V. rubrifolia), S. delastrina (generic type, on Veronica arvensis), S. decaisneana, and S. poeltii, and from apothecia on V. hederifolia agg. and V. cymbalaria seeds. As a result, the anamorphteleomorph connection could be veri ed for Schroeteria decaisneana and S. poeltii based on a 100% ITS similarity between both morphs, whereas Ciboria ploettneriana in the here rede ned sense could not be connected to an anamorph. Our phylogenetic analyses show that Ciboria ploettneriana belongs in the relationship of Sclerotinia, Stromatinia, and Grovesinia rather than Ciboria, but its placement was not supported. Also Schroeteria poeltii clustered unresolved in this relationship but has a much higher molecular distance to those. The remaining three Schroeteria spp. formed a supported monophyletic group, the Schroeteria core clade, which clustered with medium to low support distantly to a member of the Monilinia alpina group of section Disjunctoriae (M. jezoensis). ITS distances of 5-6.3% were found among members of the Schroeteria core clade, and 13.8-14.7% between the core clade and S. poeltii. The high distance of S. poeltii re ects its deviating chlamydospore morphology. Despite the high heterogeneity in the available ITS and LSU data, Schroeteria is accepted here under inclusion of S. poeltii as a genus distinct from Monilinia, particularly because of its very special anamorphs. A similar heterogeneity in rDNA analyses was observed in Monilinia and other genera of Sclerotiniaceae. Protein-coding genes should be investigated in order to obtain a more natural phylogeny within the Sclerotiniaceae. which are important plant pathogens and also known for their teleomorph-typi ed names Botryotinia Whetzel and Monilinia Honey. Most members of Sclerotiniaceae possess phialidic microconidial synanamorphs which are either formed directly from ascospores or on short germ tubes (Schumacher & Kohn 1985). The genus Schroeteria G. Winter, a group of false smut fungi, which over a long time has been misplaced in Ustilaginales (now Ustilaginomycetes), is extraordinary in forming sori of pigmented mitosporic diaspores, which are classi ed as chlamydospores, in fruits of different Veronica spp. They form a powdery spore mass which at maturity often completely lls the capsules of their host. The chlamydospores are roundish, warted, somewhat thick-walled, and show light yellowish-to reddish-or greyish-brown colours under transmitted light.but appear macroscopically dark brown to blackish. Schroeteria also possesses a phialidic microconidial synanamorph that develops on the chlamydospores, for which it was assumed to represent a member of Sclerotiniaceae (Brefeld 1883, 1912, Vánky 1982, Nagler et al. 1989). The mycelium of Schroeteria spp. destroys the interior (seeds and/or funiculi and placenta) of the capsules of living plants without forming a dark stroma. During 1986-2019, two morphologically similar sclerotiniaceous discomycetes have been collected on fallen previous year's seeds of Veronica hederifolia agg. (ivy-leaved speedwell) at different sites of central Europe. In the rst collection made in 1986 by P. Blank near Schaffhausen (Switzerland), the substrate was misinterpreted as gall of a gall wasp, therefore, the species was compared with gall
iForest - Biogeosciences and Forestry, 2018
Biogeosciences and Forestry Biogeosciences and Forestry The effect of silver and copper nanoparti... more Biogeosciences and Forestry Biogeosciences and Forestry The effect of silver and copper nanoparticles on the growth and mycorrhizal colonisation of Scots pine (Pinus sylvestris L.) in a container nursery experiment (§) Marta Aleksandrowicz-Trzcińska (1) , Adam Szaniawski (1) , Marcin Studnicki (2) , Magdalena Bederska-Błaszczyk (3) , Jacek Olchowik (1-4) , Alexander Urban (5) Recent research points to the possibility of nanoparticles being used as fertilisers, growth stimulators, and promoters of plant resistance or pesticides. In this study, we sought to determine the influence of nanoparticles of silver and copper (AgNPs and CuNPs) on growth parameters and spontaneous mycorrhizal colonisation of roots in 2-year-old container-grown seedlings of Scots pine. Foliar applications of nanoparticles were made through two growing seasons, four times a season, at concentrations of 0, 5, 25 and 50 ppm. Comparisons of the ultrastructures characterising the needles, stems and roots of the treated or untreated pines were conducted with transmission electron microscopy (TEM). The deployed CuNPs stimulated mycorrhizal colonisation at all concentrations, although the growth of seedlings was only promoted at a concentration of 25 ppm. Higher concentrations of AgNPs (25 and 50 ppm) inhibited the formation of mycorrhizae, though the lowest concentration (5 ppm) produced an increase in both mycorrhizal colonisation and the dry mass of roots. The species of ectomycorrhizal fungi found were Thelephora terrestris, Suillus bovinus and Sphaerosporella brunnea. The TEM results comparing treated and control (untreated) needles revealed changes in the chloroplasts from lensshaped to spherical. Furthermore, an increase in the number of plastoglobules and the presence of large osmophilic globules in the cytoplasm associated solely with the needles of pines receiving 50 ppm nanoparticles were observed. In contrast, ultrastructural changes in stems and roots associated with the applications of NPs were not found. Overall, the results indicated that CuNPs and AgNPs could be used as stimulators of growth in general, and mycorrhizal colonisation in particular, among container-grown Scots pines. However, further work is needed to determine their optimal doses and concentrations.
Your article is protected by copyright and all rights are held exclusively by German Mycological ... more Your article is protected by copyright and all rights are held exclusively by German Mycological Society and Springer-Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Forests, 2019
We describe the ectomycorrhizal (ECM) root tips and the diversity of mycorrhizal fungal species a... more We describe the ectomycorrhizal (ECM) root tips and the diversity of mycorrhizal fungal species at three English oak (Quercus robur) sites (two 120 year old sites and one 60 year old site). The three oak stands in decline, located in western Poland, were characterized by a low degree of vital ECM colonization: 30.2%, 29.1% and 25.6% at Krotoszyn (K), Piaski (P) and Karczma Borowa (KB), respectively. DNA (ITS) barcoding revealed a total of 18 ECM fungal species. Based on exploration types, ectomycorrhizae were classified with respect to ecologically relevant features. The contact type was significantly correlated with C:N and Corg, while the short distance type was correlated with Ca, phosphorus (P2O5) and pH. The medium distance exploration type was significantly correlated with fine-grained soil particle size fractions: coarse silt (0.05–0.02 mm) and fine silt (0.02–0.002 mm), and clay (<0.002 mm). The long distance type showed a similar pattern to the medium distance smooth typ...
Mycological Progress, 2015
Cryptogamie Mycologie, 2010
Within the basidiomycetes, the vast majority of known mycorrhizal species are homobasidiomycetes.... more Within the basidiomycetes, the vast majority of known mycorrhizal species are homobasidiomycetes. It was therefore surprising when molecular and ultrastructural studies revealed a broad diversity of mycorrhizal associations involving members of the heterobasidiomycetous Sebacinaceae, fungi which, due to their inconspicuous basidiomes, have been often overlooked. To investigate the phylogenetic position of the Sebacinaceae within the basidiomycetes and to infer phylogenetic relationships within the Sebacinaceae, we made molecular phylogenetic analyses based on nuclear rDNA. We present a well-resolved phylogeny of the main lineages of basidiomycetes which suggests that the Sebacinaceae is the most basal group with known mycorrhizal members. Since more basal taxa of basidiomycetes consist of predominantly mycoparasitic and phytoparasitic fungi, it seems possible that a mycorrhizal life strategy, which was transformed into a saprotrophic strategy several times convergently, is an apomorphic character for the Hymenomycetidae. Mycorrhizal taxa of Sebacinaceae, including mycobionts of ectomycorrhizas, orchid mycorrhizas, ericoid mycorrhizas, and jungermannioid mycorrhizas, are distributed over two subgroups. One group contains species with macroscopically visible basidiomes, whereas members of the other group probably lack basidiomes. Sebacina appears to be polyphyletic; current species concepts in Sebacinaceae are questionable. Sebacina vermifera sensu Warcup & Talbot consists of a broad complex of species possibly including mycobionts of jungermannioid and ericoid mycorrhizas.
Phyton-annales Rei Botanicae, Jul 25, 2000
Mycological Progress, 2022
Three little known, morphologically similar species of Sclerotiniaceae which form their apothecia... more Three little known, morphologically similar species of Sclerotiniaceae which form their apothecia on fallen stromatized Veronica seeds are described and illustrated in detail based on fresh collections or moist chamber cultures of infected seeds: Ciboria ploettneriana, Schroeteria decaisneana, and Schroeteria poeltii. The former two were found on Veronica hederifolia agg. at different sites of temperate central Europe, the latter on V. cymbalaria in a mediterranean region of Spain. The latter two are anamorph-typi ed and here reported for the rst time with their teleomorph. Ciboria ploettneriana was described by Kirschstein as Sclerotiniaploettneriana on seeds of V. hederifolia agg. but is currently treated in Ciboria. Based on the reexamination of four syntype specimens in B it became evident that Kirschstein confused the two species on V. hederifolia. A lectotype is therefore designated for S. ploettneriana. Members of Schroeteria are speci c plant parasites infecting fruits of different Veronica spp. Schroeteria has earlier been referred to the Ustilaginales (Basidiomycota) based on its smut-like chlamydospores, but later light-microscopic and ultrastructural studies suggested that it represents a false smut fungus belonging to the Sclerotiniaceae (Helotiales). rDNA sequences were obtained from chlamydospores of Schroeteria bornmuelleri (on V. rubrifolia), S. delastrina (generic type, on Veronica arvensis), S. decaisneana, and S. poeltii, and from apothecia on V. hederifolia agg. and V. cymbalaria seeds. As a result, the anamorphteleomorph connection could be veri ed for Schroeteria decaisneana and S. poeltii based on a 100% ITS similarity between both morphs, whereas Ciboria ploettneriana in the here rede ned sense could not be connected to an anamorph. Our phylogenetic analyses show that Ciboria ploettneriana belongs in the relationship of Sclerotinia, Stromatinia, and Grovesinia rather than Ciboria, but its placement was not supported. Also Schroeteria poeltii clustered unresolved in this relationship but has a much higher molecular distance to those. The remaining three Schroeteria spp. formed a supported monophyletic group, the Schroeteria core clade, which clustered with medium to low support distantly to a member of the Monilinia alpina group of section Disjunctoriae (M. jezoensis). ITS distances of 5-6.3% were found among members of the Schroeteria core clade, and 13.8-14.7% between the core clade and S. poeltii. The high distance of S. poeltii re ects its deviating chlamydospore morphology. Despite the high heterogeneity in the available ITS and LSU data, Schroeteria is accepted here under inclusion of S. poeltii as a genus distinct from Monilinia, particularly because of its very special anamorphs. A similar heterogeneity in rDNA analyses was observed in Monilinia and other genera of Sclerotiniaceae. Protein-coding genes should be investigated in order to obtain a more natural phylogeny within the Sclerotiniaceae. which are important plant pathogens and also known for their teleomorph-typi ed names Botryotinia Whetzel and Monilinia Honey. Most members of Sclerotiniaceae possess phialidic microconidial synanamorphs which are either formed directly from ascospores or on short germ tubes (Schumacher & Kohn 1985). The genus Schroeteria G. Winter, a group of false smut fungi, which over a long time has been misplaced in Ustilaginales (now Ustilaginomycetes), is extraordinary in forming sori of pigmented mitosporic diaspores, which are classi ed as chlamydospores, in fruits of different Veronica spp. They form a powdery spore mass which at maturity often completely lls the capsules of their host. The chlamydospores are roundish, warted, somewhat thick-walled, and show light yellowish-to reddish-or greyish-brown colours under transmitted light.but appear macroscopically dark brown to blackish. Schroeteria also possesses a phialidic microconidial synanamorph that develops on the chlamydospores, for which it was assumed to represent a member of Sclerotiniaceae (Brefeld 1883, 1912, Vánky 1982, Nagler et al. 1989). The mycelium of Schroeteria spp. destroys the interior (seeds and/or funiculi and placenta) of the capsules of living plants without forming a dark stroma. During 1986-2019, two morphologically similar sclerotiniaceous discomycetes have been collected on fallen previous year's seeds of Veronica hederifolia agg. (ivy-leaved speedwell) at different sites of central Europe. In the rst collection made in 1986 by P. Blank near Schaffhausen (Switzerland), the substrate was misinterpreted as gall of a gall wasp, therefore, the species was compared with gall
iForest - Biogeosciences and Forestry, 2018
Biogeosciences and Forestry Biogeosciences and Forestry The effect of silver and copper nanoparti... more Biogeosciences and Forestry Biogeosciences and Forestry The effect of silver and copper nanoparticles on the growth and mycorrhizal colonisation of Scots pine (Pinus sylvestris L.) in a container nursery experiment (§) Marta Aleksandrowicz-Trzcińska (1) , Adam Szaniawski (1) , Marcin Studnicki (2) , Magdalena Bederska-Błaszczyk (3) , Jacek Olchowik (1-4) , Alexander Urban (5) Recent research points to the possibility of nanoparticles being used as fertilisers, growth stimulators, and promoters of plant resistance or pesticides. In this study, we sought to determine the influence of nanoparticles of silver and copper (AgNPs and CuNPs) on growth parameters and spontaneous mycorrhizal colonisation of roots in 2-year-old container-grown seedlings of Scots pine. Foliar applications of nanoparticles were made through two growing seasons, four times a season, at concentrations of 0, 5, 25 and 50 ppm. Comparisons of the ultrastructures characterising the needles, stems and roots of the treated or untreated pines were conducted with transmission electron microscopy (TEM). The deployed CuNPs stimulated mycorrhizal colonisation at all concentrations, although the growth of seedlings was only promoted at a concentration of 25 ppm. Higher concentrations of AgNPs (25 and 50 ppm) inhibited the formation of mycorrhizae, though the lowest concentration (5 ppm) produced an increase in both mycorrhizal colonisation and the dry mass of roots. The species of ectomycorrhizal fungi found were Thelephora terrestris, Suillus bovinus and Sphaerosporella brunnea. The TEM results comparing treated and control (untreated) needles revealed changes in the chloroplasts from lensshaped to spherical. Furthermore, an increase in the number of plastoglobules and the presence of large osmophilic globules in the cytoplasm associated solely with the needles of pines receiving 50 ppm nanoparticles were observed. In contrast, ultrastructural changes in stems and roots associated with the applications of NPs were not found. Overall, the results indicated that CuNPs and AgNPs could be used as stimulators of growth in general, and mycorrhizal colonisation in particular, among container-grown Scots pines. However, further work is needed to determine their optimal doses and concentrations.
Your article is protected by copyright and all rights are held exclusively by German Mycological ... more Your article is protected by copyright and all rights are held exclusively by German Mycological Society and Springer-Verlag Berlin Heidelberg. This e-offprint is for personal use only and shall not be selfarchived in electronic repositories. If you wish to self-archive your article, please use the accepted manuscript version for posting on your own website. You may further deposit the accepted manuscript version in any repository, provided it is only made publicly available 12 months after official publication or later and provided acknowledgement is given to the original source of publication and a link is inserted to the published article on Springer's website. The link must be accompanied by the following text: "The final publication is available at link.springer.com".
Forests, 2019
We describe the ectomycorrhizal (ECM) root tips and the diversity of mycorrhizal fungal species a... more We describe the ectomycorrhizal (ECM) root tips and the diversity of mycorrhizal fungal species at three English oak (Quercus robur) sites (two 120 year old sites and one 60 year old site). The three oak stands in decline, located in western Poland, were characterized by a low degree of vital ECM colonization: 30.2%, 29.1% and 25.6% at Krotoszyn (K), Piaski (P) and Karczma Borowa (KB), respectively. DNA (ITS) barcoding revealed a total of 18 ECM fungal species. Based on exploration types, ectomycorrhizae were classified with respect to ecologically relevant features. The contact type was significantly correlated with C:N and Corg, while the short distance type was correlated with Ca, phosphorus (P2O5) and pH. The medium distance exploration type was significantly correlated with fine-grained soil particle size fractions: coarse silt (0.05–0.02 mm) and fine silt (0.02–0.002 mm), and clay (<0.002 mm). The long distance type showed a similar pattern to the medium distance smooth typ...
Mycological Progress, 2015
Cryptogamie Mycologie, 2010
Within the basidiomycetes, the vast majority of known mycorrhizal species are homobasidiomycetes.... more Within the basidiomycetes, the vast majority of known mycorrhizal species are homobasidiomycetes. It was therefore surprising when molecular and ultrastructural studies revealed a broad diversity of mycorrhizal associations involving members of the heterobasidiomycetous Sebacinaceae, fungi which, due to their inconspicuous basidiomes, have been often overlooked. To investigate the phylogenetic position of the Sebacinaceae within the basidiomycetes and to infer phylogenetic relationships within the Sebacinaceae, we made molecular phylogenetic analyses based on nuclear rDNA. We present a well-resolved phylogeny of the main lineages of basidiomycetes which suggests that the Sebacinaceae is the most basal group with known mycorrhizal members. Since more basal taxa of basidiomycetes consist of predominantly mycoparasitic and phytoparasitic fungi, it seems possible that a mycorrhizal life strategy, which was transformed into a saprotrophic strategy several times convergently, is an apomorphic character for the Hymenomycetidae. Mycorrhizal taxa of Sebacinaceae, including mycobionts of ectomycorrhizas, orchid mycorrhizas, ericoid mycorrhizas, and jungermannioid mycorrhizas, are distributed over two subgroups. One group contains species with macroscopically visible basidiomes, whereas members of the other group probably lack basidiomes. Sebacina appears to be polyphyletic; current species concepts in Sebacinaceae are questionable. Sebacina vermifera sensu Warcup & Talbot consists of a broad complex of species possibly including mycobionts of jungermannioid and ericoid mycorrhizas.