Adriano Afonso Spielmann

New insights into relationships of lichen-forming Dothideomycetes

Here we continue to investigate the phylogenetic relationships of taxa ascribed to the primarily lichen-forming families Trypetheliaceae, Monoblastiaceae and Arthopyreniaceae. We demonstrate that the genera Julella and Arthopyrenia do not form monophyletic groups with taxa from these genera instead being placed both in Pleosporales and Trypetheliales. Within Dothideomycetes, lichen-forming species with brown ascospores are generally placed in the genera Mycomicrothelia, Architrypethelium, and Aptrootia in the family Trypetheliaceae. We tested the taxonomic placement of Anisomeridium phaeospermum, in Monoblastiaceae. This species produces brown-spores with wall ornamentation and therefore appears morphologically similar to Mycomicrothelia. Despite these morphological similarities, molecular data confirmed its placement in Anisomeridium. Consequently, the distinction between these two genera is in need of clarification and ascus characters are identified as the principal discriminating feature. Finally, we identify the non-lichenized taxa Heleiosa barbatula and Funbolia dimorpha as being part of the otherwise lichen-forming family Monoblastiaceae. This is confirmed by the perithecial anatomy of the sexually reproducing Heleiosa barbatula.

Biomonitoring of lead in Antarctic lichens using laser ablation inductively coupled plasma mass spectrometry

A method for direct determination of Pb by LA-ICP-MS in lichen samples collected in a heavily anthropogenically impacted area of Maritime Antarctica was developed. The lichen samples were cryogenically ground and digested with nitric acid and hydrogen peroxide. Lead determination by solution-based ICP-MS was validated by the use of 2 certified reference materials. Once the Pb concentrations were measured with adequate accuracy and precision, a method for its direct determination by LA-ICP-MS was developed. The laser ablation parameters were optimized by the use of a Doehlert design matrix. The final optimized conditions were: laser energy (60%), spot size (150 μm) and repetition rate (10 Hz). Lead concentration of the analyzed lichen samples were plotted against the intensity of the lead isotopes (208Pb, 207Pb and 206Pb) determined by LA-ICP-MS. Satisfactory linear correlation factors were obtained when 13C was used as internal standard. Lead distribution profiles in lichen thalli cross-sections were also obtained. By these results, LA-ICP-MS emerges as a potential analytical tool for Pb concentration estimation in lichen samples. Minimum amount of sample required, bioimaging capability, high analytical throughput, and minimization of waste generation are the major analytical features of this approach. The significant differences between the Pb concentration in the lichen samples from the control site (1.12 ± 0.05 mg kg−1) and from the impacted points (mean = 5.03 ± 0.57 mg kg−1) permitted qualify these organisms as good biomonitors. Elemental bioimaging of lichens demonstrated that the medulla region of lichen thalli is consistently the main atmospheric lead bioaccumulating lichen tissue.

Parmotrema s.l. (Parmeliaceae, lichenized Ascomycota) from Serra Geral slopes in central Rio Grande do Sul state, Brazil

Em um levantamento das especies de Parmotrema A. Massal. que ocorrem nos barrancos e peraus de uma regiao central do Rio Grande do Sul, 31 especies foram encontradas, as quais podem ser divididas em tres grupos morfologicos, que correspondem a Canomaculina Elix & Hale, Parmotrema s. str. e Rimelia Hale & Fletcher. Descricoes, ilustracoes e comentarios sobre especies proximas sao fornecidos, baseando-se no material encontrado.

From one to six: unrecognized species diversity in the genus Acantholichen (lichenized Basidiomycota: Hygrophoraceae)

We present a taxonomic revision of the lichenized basidiomycete genus Acantholichen, species of which produce a characteristic blue-gray, microsquamulose thallus with spiny apical hyphal cells known as acanthohyphidia. Since its discovery, the genus was thought to be monospecific, only including the generic type, A. pannarioides. However, a detailed morphological and anatomical study of recently collected specimens from the Galápagos, Costa Rica, Brazil and Colombia, combined with a molecular phylogenetic analysis of the internal transcribed spacer (ITS1-5.8S-ITS2) region and 28S of the nuc rDNA and RPB2 sequences, revealed a much more diverse and widespread species assemblage. Based on the results of these analyses, we describe five new species in the genus: A. albomarginatus, A. campestris, A. galapagoensis, A. sorediatus and A. variabilis. We also provide an identification key to all species, anatomical and morphological descriptions, photographs and a table comparing main characters of each species.

Characterization and mapping of plant communities at Hennequin Point, King George Island, Antarctica

King George Island is the largest island and the principal area used for research bases in Antarctica. Argentina, Brazil, Chile, China, Poland, Russia, South Korea and Uruguay have permanent open bases on this island. Other countries have seasonal summer stations on different parts of this island, which demonstrates that human impact is strong on King George Island relative to other areas in the maritime and continental Antarctica. The objective of this work was to present a phytosociological approach for ice-free areas of Hennequin Point, eastern coast of Admiralty Bay, King George Island. The study started with the classification and description of the plant communities based primarily on phytosociological and biodiversity data. The area was mapped using an Astech Promark II® DGPS, yielding sub-metric precision after post-processing with software. The plant communities were described as follows: (1) lichen and moss cushion formation; (2) moss carpet formation; (3) fellfield formation; (4) grass and cushion chamaephyte formation; and (5) Deschampsia Antarctica–lichen formation. Characterizations and distributions of the plant communities are presented on a map at a scale of 1:5000. The plant communities found at Hennequin Point, in general, differ from those found in other areas of the Admiralty Bay region, probably because of the concentration of skua nests in the area and the relief singularities. We conclude by highlighting the importance of the study of plant species found in the ice-free areas of the Antarctic with respect to environmental monitoring and for evaluating global climate and environmental changes.

Avaliação da sensibilidade de plantas jovens de quiabo (Abelmoschus esculentus (L.) Moench. - Malvaceae) ao ozônio

A sensibilidade de Abelmoschus esculentus ao ozonio (O3) foi determinada em plantas expostas por quatro dias, seis horas/dia, ao ar filtrado (AF) e ao AF enriquecido com 80 ppb de O3 (AF+O3), em câmaras de fumigacao, analisando-se sintomas foliares visiveis e alteracoes nas trocas gasosas e em antioxidantes. Avaliaram-se os sintomas foliares diariamente e as trocas gasosas e antioxidantes (acido ascorbico e superoxido dismutase) ao fim do experimento. Todas as plantas em AF+O3 apresentaram sintomas foliares, caracterizados por pontuacoes avermelhadas na superficie adaxial, entre as nervuras. Em media, o indice de injuria foliar foi de 15% e a severidade de 62%. Fotossintese liquida, condutância estomatica, transpiracao, concentracao de acido ascorbico e atividade da superoxido dismutase foram reduzidas significativamente nestas plantas, em comparacao com as mantidas sob ar filtrado. Os resultados sugerem que Abelmoschus esculentus e sensivel ao O3, apresentando baixos niveis de defesas antioxidativas e disturbios fisiologicos.

A new Lepraria from Brazil

Lepraria brasiliensis is described from Minas Gerais, Brazil. It is mainly characterized by the presence of thamnolic acid and atranorin as chemical constituents.