No abstract

1. Reliable determination of organisms is a prerequisite to explore their spatial and temporal occurrence and to study their evolution, ecology, and dispersal. In Europe, Bavaria (Germany) provides an excellent study system for research on the origin and diversification of freshwater organisms including dinophytes, due to the presence of extensive lake districts and ice age river valleys. Bavarian freshwater environments are ecologically diverse and range from deep nutrient-poor mountain lakes to shallow nutrient-rich lakes and ponds.2. We obtained amplicon sequence data (V4 region of small subunit-rRNA, c. 410 bp long) from environmental samples collected at 11 sites in Upper Bavaria. We found 186 operational taxonomic units (OTUs) associated with Dinophyceae that were further classified by means of a phylogenetic placement approach.3. The maximum likelihood tree inferred from a well-curated reference alignment comprised a systematically representative set of 251 dinophytes, covering the currently known molecular diversity and OTUs linked to type material if possible. Environmental OTUs were scattered across the reference tree, but accumulated mostly in freshwater lineages, with 79% of OTUs placed in either Apocalathium, Ceratium, or Peridinium, the most frequently encountered taxa in Bavaria based on morphology.4. Twenty-one Bavarian OTUs showed identical sequences to already known and vouchered accessions, two of which are linked to type material, namely Palatinus apiculatus and Theleodinium calcisporum. Particularly within Peridiniaceae, delimitation of Peridinium species was based on the intraspecific sequence variation. 5. Our approach indicates that high-throughput sequencing of environmental samples is effective for reliable determination of dinophyte species in Bavarian lakes.We further discuss the importance of well-curated reference databases that remain to be developed in the future. K E Y W O R D Samplicon sequencing, dinoflagellates, distribution, molecular phylogenetics, operational taxonomic unit

No abstract

No abstract

Constituting one of Earth’s major biomes, steppes are characterised by naturally treeless extra-tropical vegetation. The formation of the Eurasian steppe belt, the largest steppe region in the world, began in Central Asia during the Neogene. In the glacial stages of the Pleistocene, steppe displaced forest vegetation, which in turn recolonised the area during the warmer interglacial periods, thus affecting the distribution of plants adapted to these habitats. Krascheninnikovia ceratoides (Chenopodiaceae) is a plant characteristic of dry steppe and semi-desert formations. Earlier studies showed that the ancestor of this autochthonous steppe element originated in Central Asia during the Miocene/Pliocene, i.e., in the same region and at the same time as the first appearance of steppe vegetation. However, as the extant lineages of Krascheninnikovia ceratoides diversified only 2.2 ± 0.9 Mya, it may represent a modern element of current dry steppe and semi-desert formations, rather than a component of the first steppe precursors of the Miocene. As such, it may have capitalised on the climatic conditions of the cold stages of the Quaternary to expand its range and colonise suitable habitats outside of its area of origin. To test this hypothesis, phylogeographic methods were applied to high-resolution genotyping-by-sequencing data. Our results indicate that Krascheninnikovia originated in western Central Asia and the Russian Altai, then spread to Europe in the West, and reached North America in the East. The populations of eastern Central Asia and North America belong to the same clade and are genetically clearly distinct from the Euro-Siberian populations. Among the populations west of the Altai Mountains, the European populations are genetically distinct from all others, which could be the result of the separation of populations east and west of the Urals caused by the Pleistocene transgressions of the Caspian Sea.

No abstract

No abstract

Blastodinium contortum Chatton [isolated from Paracalanus cf. parvus (Claus, 1863)] n.inf. eastern North Pacific, off USA-CA: Gulf of California, station 3 (24°14'N, 110°20'W) Jun 11, 2008 n.inf. FJ228701 (SSU+ITS+LSU) Coats et al. (2008) Blastodinium crassum Chatton [isolated from Paracalanus cf. parvus (Claus, 1863)] n.inf. eastern North Pacific, off USA-CA: Gulf of California, station 2 (24°13'N, 110°20'W) Jun 10, 2008 n.inf. FJ228702 (SSU+ITS+LSU) Coats et al. (2008) †Calcicarpinum bivalvum G.Versteegh [= "Pentapharsodinium" tyrrhenicum (Balech) Montresor, Zingone & D.Marino] GeoB*230 Mediterranean Sea, Ionian Sea, off Italy: Gulf of Taranto (40°07'N, 17°19'E) Oct 26, 2002 D. Saracino [M. Kirsch] s.n.