Biogeography of the cosmopolitan terrestrial diatom Hantzschia amphioxys sensu lato based on molecular and morphological data

Until now, the reported diversity of representatives from the genus Hantzschia inhabiting soils from different parts of Eurasia was limited to the few species H. amphioxys, H. elongata and H. vivax and some of their infraspecific taxa. We have studied the morphology, ultrastructure and phylogeny of 25 soil diatom strains, which according to published description would be assigned to "H. amphioxys sensu lato" using 18S rDNA, 28S rDNA and rbcL. We show that strains are made up of seven different species of Hantzschia, including five new for science. Five strains were identified as H. abundans. This species has a slight curvature of the raphe near its external proximal ends. Four of the examined strains were represented by different populations of H. amphioxys and their morphological characteristics fully correspond with its isolectotype and epitype. The main specific features of this species include 21-25 striae in 10 mu m, 6-11 fibulae in 10 mu m, 40-50 areolae in 10 mu m and internal proximal raphe endings bent in opposite directions. H. attractiva sp. nov., H. belgica sp. nov., H. parva sp. nov., H. pseudomongolica sp. nov. and H. stepposa sp. nov. were described based on differences in the shape of the valves, significant differences in dimensions, a lower number of striae and areolae in 10 mu m and the degree and direction of deflection of the internal central raphe endings. Based on the study of the morphological variability and phylogeny of soil Hantzschia-species from different geographical locations we conclude that while some species such as H. amphioxys are truly cosmopolitan in their distributions, some sympatric populations of pseudocryptic taxa exist in the Holarctic

Diatoms in the Bottom Sediments of Two Closely Located Lakes in Khakassia

Diatoms are one of the main paleo-indicators of lake changes, as they are preserved in bottom sediments for centuries. The present study reports new data on diatoms in the bottom sediments of Lake Shira and compares them with diatoms from the bottom sediments of Lake Utichye-3, which is situated close to Lake Shira (Khakassia, Russia). The results showed that both lakes have undergone changes in the past, and the species compositions have changed several times. The dominant species in Lake Shira is now Cyclotella choctawhatcheeana Prasad, a planktonic marine species. Rhopalodia constricta (W. Smith) Krammer is a benthic brackish or freshwater species that often occurs in Lake Shira. The lower layers of sediments, dating from approximately the 17th century, were dominated by the freshwater plankton species Aulacoseira ambigua (Grunow) Simonsen and A. italica (Ehrenberg) Simonsen; Staurosira venter sensu lato (Ehrenberg) Cleve & JD Möller, a benthic freshwater species, also occurred there. The bottom sediments of Lake Utichye-3, with the exception of the lower layers, were dominated by C. meneghiniana Kützing (a planktonic brackish or freshwater species). This species was also found in the upper layers of the bottom sediments of Lake Shira. This suggests that conditions in Lake Shira and Lake Utichye-3 were once similar. Surirella peisonis Pantocsek (a marine species) prevailed in the lower layers of the core of Lake Utichye-3. Thus, we can say that the climatic conditions in the region where the lakes are situated have changed several time

Features of Sexual Reproduction and Mating System of Ulnaria acus (Bacillariophyta)

Sexual reproduction and mating system of the freshwater diatom Ulnaria acus (Bacillariophyta) was described for the first time. Mating system of the species includes, apparently, only heterothallic way of reproduction: during the three-year observation period neither male nor female clones have shown the ability to reproduce homothallically. The type of sexual reproduction is cis-anisogamous; in many details it similar with reproduction of closely related species Ulnaria ulna, Tabularia fasciculata, and Tabularia tabulat

Four new species from the diatom (Bacillariophyceae) genus Adlafia Moser, Lange-Bertalot & Metzeltin from waterbodies of Vietnam

Four species of the diatom genus were found from waterbodies of Vietnam and described as new to science. Their formal descriptions are presented herein and they are illustrated by light and scanning electron micrographs. These new species are: Glushch., Kulik. Kociolek, , Glushch., Kulik. Kociolek, , Glushch., Kulik. Kociolek, and Glushch., Kulik. Kociolek, These species are then compared to other similar taxa. Our new findings add to the number of species in this interesting genus and contribute to our understanding of the unique diatom flora found in Vietnam. Keywords: , diatoms, morphology, new species, Southeast Asia, Vietnam</p

Investigation of chemical constituents of Eranthis longistipitata (Ranunculaceae): coumarins and furochromones

Aqueous‐ethanol extracts (70%) from the leaves of Eranthis longistipitata Regel. (Ranunculaceae Juss.)—collected from natural populations of Kyrgyzstan—were studied by liquid chromatography with high‐resolution mass spectrometry (LC‐HRMS). There was no variation of the metabolic profiles among plants that were collected from different populations. More than 160 compounds were found in the leaves, of which 72 were identified to the class level and 58 to the individual‐ compound level. The class of flavonoids proved to be the most widely represented (19 compounds), including six aglycones [quercetin, kaempferol, aromadendrin, 6‐methoxytaxifolin, phloretin, and (+)‐catechin] and mono‐ and diglycosides (the other 13 compounds). In the analyzed samples of E. longistipitata, 14 fatty acid–related compounds were identified, but coumarins and furochromones that were found in E. longistipitata were the most interesting result; furochromones khelloside, khellin, visnagin, and cimifugin were found in E. longistipitata for the first time. Coumarins 5,7‐dihydroxy‐4‐methylcoumarin, scoparone, fraxetin, and luvangetin and furochromones methoxsalen, 5‐O‐methylvisammioside, and visamminol‐3′‐O‐glucoside were detected for the first time in the genus Eranthis Salisb. For all the above compounds, the structural formulas are given. Furthermore, detailed information (with structural formulas) is provided on the diversity of chromones and furochromones in other representatives of Eranthis. The presence of chromones in plants of the genus Eranthis confirms its closeness to the genus Actaea L. because chromones are synthesized by normal physiological processes only in these members of the Ranunculaceae family

Three New Species of Placoneis Mereschkowsky (Bacillariophyceae: Cymbellales) with Comments on Cryptic Diversity in the P. elginensis-Group

Using genetic markers 18S V4 rDNA and rbcL and morphological investigation of the diatom genus Placoneis, we described three new species. The new species, Placoneis baikaloelginensis sp. nov., Placoneis subundulata sp. nov., Placoneis neohambergii sp. nov. were isolated from Russia (Lake Baikal) and Vietnam (waterbodies of C&aacute;t Ti&ecirc;n National Park (Đồng Nai Province) and Kh&aacute;nh H&ograve;a Province). We examine relationships within the Cymbellales and show that the genera Placoneis, Paraplaconeis and Geissleria are phylogenetically independent. We discuss the importance of careful identification of strains used for phylogenetic analysis and we show the history of identification of several different Placoneis elginensis strains. After careful identification of Placoneis elginensis vouchers, we found that we have a few independent species. The question of cryptic or pseudocryptic species in this context is discussed.</p

Two new species of Navicula (Bacillariophyta) from Southeast Asia

We present light and scanning electron microscopical observations on two new species of Navicula Bory sensu stricto from Southeast Asia. Navicula winoniformis Chudaev, Glushchenko, Kulikovskiy &amp; Kociolek, sp. nov. differs from taxa with similar outline and size by the combination of simple drop-like external raphe endings deflected to the primary valve side, presence of well-developed external longitudinal grooves and relatively low lineolae density. Navicula sparsilineolata Chudaev, Glushchenko, Kulikovskiy &amp; Kociolek, sp. nov. can be discriminated from the taxa of similar valve shape and size by consistently lower lineolae density, and from the majority of them also by the structure of external proximal raphe endings with small projections in proximal parts and larger triangular insertions in distal parts. Some remarks on Navicula species diversity and its distribution in the Southeast Asia are given. &nbsp;</p

The distribution of centric diatoms in different river catchments in the Anatolian Peninsula, Turkey

The diatoms are one of the most important groups of organisms for biomonitoring studies. In Turkey, most previous applications of diatoms to water quality monitoring have focused on the pennate diatoms, with almost no attention given to the centric forms. The paper presents the centric diatoms in some river catchments in Central Anatolia (Konya closed catchment and Kızılırmak) and Western Anatolia (Marmara, Sakarya, Susurluk, Akarçay, Küçük Menderes, and Meriç-Ergene in the Marmara and Aegean regions). The survey of these catchments is based on samples collected between 2009 and 2013 from 33 different locations, including some springs from Türkmen Mountain and Domaniç forest, as well as small streams and big rivers of the Anatolian Peninsula. Altogether 30 taxa were found, of which 14 are new records for the freshwater diatom flora of Turkey

Une espèce nouvelle de &lt;i&gt;Placoneis&lt;/i&gt; Mereschkowsky (Bacillariophyceae : Cymbellales) des sols humides du sud du Vietnam

Une espèce nouvelle de diatomée du genre Placoneis Mereschkowsky est décrite sur la base de données moléculaires et morphologiques. La nouvelle espèce, Placoneis asymmetricus Glushchenko, Kezlya, Kulikovskiy &amp; Kociolek, sp. nov., se caractérise morphologiquement par des valves légèrement asymétriques le long de l’axe apical selon nos observations au microscope optique et électronique à balayage de l’extérieur et de l’intérieur des valves. Les données moléculaires, extraites de cellules vivantes, sont utilisées pour la reconstruction phylogénétique basée sur l’ADNr 18S V4 et les marqueurs génétiques rbcL des taxons du genre Placoneis et d’autres diatomées de l\u27ordre des Cymbellales D.G.Mann. Des comparaisons avec d’autres espèces morphologiquement et moléculairement proches sont données.A new diatom species of the genus Placoneis Mereschkowsky is described on the basis of molecular and morphological data. The new species, Placoneis asymmetricus Glushchenko, Kezlya, Kulikovskiy &amp; Kociolek, sp. nov., is morphologically characterized by slightly asymmetrical valves along the apical axis based on light and scanning electron microscopy of the exterior and interior of valves. Molecular data, which are derived from live cells, are used for phylogenetic reconstruction based on 18S V4 rDNA and rbcL gene markers of taxa from the genus Placoneis and other diatoms in the order Cymbellales D.G.Mann. Comparisons with other morphologically and molecularly closely-related species are given.</p