Microcystis aeruginosa and M. wesenbergii Were the Primary Planktonic Microcystin Producers in Several Bulgarian Waterbodies (August 2019)

The rising interest in harmful cyanoprokaryote blooms promotes an increase of phycological and ecological research on potentially toxic species and their hazardous substances. The present study aimed to identify the main microcystin (MC) producers and their contribution to the phytoplankton of shallow waterbodies in Bulgaria, applying different methods. The sampling was performed in August 2019 in nine lakes and reservoirs, two of which (reservoirs Kriva Reka and Izvornik 2) were studied for the first time. The high contribution of cyanoprokaryotes to the total species composition and phytoplankton abundance was proved by light microscopic (LM) observations and HPLC analysis of marker pigments. The LM identification of potential MC-producers was supported by PCR amplification of mcyE and mcyB genes. The MCs amounts, detected by HPLC-DAD, varied by sites with a range from undetectable concentrations to 0.46 g L 1 with only one recorded variant, namely MC-LR. It was found only in the reservoirs Mandra and Durankulak, while toxigenic MC-strains were obtained by PCR from five more waterbodies. Both LM and PCR demonstrated that the MC-producers were Microcystis aeruginosa and M. wesenbergii, despite their occurrence in low amounts (<0.5–5% of the total biomass) when filamentous cyanoprokaryotes dominated.Peer reviewe

Cyanocystopsis kitagatae gen. et sp. nov. (Cyanoprokaryota/ Cyanobacteria) from the tropical lake Kitagata (Uganda, Africa)

peer reviewedThe paper describes a new genus and new species of Cyanoprokaryota, referred to Pleurocapsales incertae sedis – Cyanocystopsis kitagatae gen. et sp. nov. The new taxon is characterized by the presence of two different stages (filamentous, formed by spherical cells and stalked bundles of claviform cells). The branching of filaments, which leads to the formation of clusters of claviform cells, is caused by cell division, which slightly resembles the true-branching of cyanoprokaryotes. However, this division is peculiar by its subsequent character and excentric disposition of the daughter cells, which leads to the formation of specific tetrads, from which the claviform cells develop. Spores (aplanospores) and vegetative reproductive stages of the alga have been observed. The new species was found as a dominant in a fixed phytoplankton sample from the small, hypertrophic and hypersaline tropical crater lake Kitagata (Uganda, Africa). The pigment marker analysis of the same sample proved the high (ca 96%) cyanoprokaryote contribution to the phytoplankton biomass.HIP

Functional Relationships of Wood Anatomical Traits in Norway Spruce

The quantitative assessment of wood anatomical traits offers important insights into those factors that shape tree growth. While it is known that conduit diameter, cell wall thickness, and wood density vary substantially between and within species, the interconnection between wood anatomical traits, tree-ring width, tree height and age, as well as environment effects on wood anatomy remain unclear. Here, we measure and derived 65 wood anatomical traits in cross-sections of the five outermost tree rings (2008–2012) of 30 Norway spruce [Picea abies (L.) H. Karst.] trees growing along an altitudinal gradient (1,400–1,750 m a.s.l.) in the northern Apennines (Italy). We assess the relationship among each anatomical trait and between anatomical trait groups according to their function for (i) tree-ring growth, (ii) cell growth, (iii) hydraulic traits, and (iv) mechanical traits. The results show that tree height significantly affects wood hydraulic traits, as well as number and tangential diameter of tracheids, and ultimately the total ring width. Moreover, the amount of earlywood and latewood percentage influence wood hydraulic safety and efficiency, as well as mechanical traits. Mechanically relevant wood anatomical traits are mainly influenced by tree age, not necessarily correlated with tree height. An additional level of complexity is also indicated by some anatomical traits, such as latewood lumen diameter and the cell wall reinforcement index, showing large inter-annual variation as a proxy of phenotypic plasticity. This study unravels the complex interconnection of tree-ring tracheid structure and identifies anatomical traits showing a large inter-individual variation and a strong interannual coherency. Knowing and quantifying anatomical variation in cells of plant stem is crucial in ecological and biological studies for an appropriate interpretation of abiotic drivers of wood formation often related to tree height and/or tree age

Fifth European Dirofilaria and Angiostrongylus Days (FiEDAD) 2016

Peer reviewe

Der Schatz des Piraten, suomi

Nimiösivulla myös: Suomennos.Suomentanut Aina Someri