annonex2embl: automatic preparation of annotated DNA sequences for bulk submissions to ENA

Generic concepts and species diversity within the Gynoxyoid clade (Senecioneae, Compositae)

The Gynoxyoid clade of the Senecioneae (Asteraceae) until now included the five genera Aequatorium, Gynoxys, Nordenstamia, Paracalia and Paragynoxys as diagnosed using selected morphological characters. In their pre-phylogenetic circumscription, the genera Aequatorium and Paragynoxys were considered to inhabit the northern Andes in contrast to Nordenstamia and Paracalia that occur in the central Andes. The most species-rich genus, Gynoxys, was believed to be distributed throughout the Andes. We use a recently established plastid phylogenomic framework that rendered Gynoxys paraphyletic to further evaluate the delimitation of genera in the Gynoxyoid clade. We examine the morphological variation of all members of the Gynoxyoid to identify characters potentially informative at genus level. This results in a matrix of eleven, mostly multistate characters, including those originally used to diagnose these genera. The ancestral character state inference displays a high level of homoplasy, but nevertheless supports the recognition of four genera. Aequatorium is characterised by white radiate capitula. Paracalia and Paragynoxys share white flowers and floral characteristics, such as flower opening and length of disc flowers lobes, as plesiomorphic states, but differ in habit (scandent shrubs vs. trees). Paracalia also retained white flowers, but its two species are characterised by the absence of outer phyllaries. The genera Gynoxys and Nordenstamia comprise species with yellow capitula which appear to be a derived feature in the Gynoxyoids. The genus Nordenstamia, with eight species, is synonymised under Gynoxys since molecular evidence shows its species nested within various parts of the Gynoxys subclade and the morphological variation of Nordenstamia falls well within that of Gynoxys. With the goal to assign all species to four genera (Aequatorium, Gynoxys, Paracalia and Paragynoxys), we assess the states for the eleven characters for all members of the Gynoxyoids and generate new ETS and ITS sequences for 171 specimens belonging to 49 species to further support their generic placement. We provide a taxonomic treatment for the four genera recognised here including amended diagnoses and morphological descriptions. Furthermore, a species-level taxonomic backbone is elaborated for all genera using electronic tools that list 158 currently accepted names and synonyms (209 names in total) with the respective protologue and type information, as well as notes on the current understanding of species limits. Eleven names are newly synonymised, two are lectotypified and eight are newly transferred to other genera.

Photosynthetic, Respirational, and Growth Responses of Six Benthic Diatoms from the Antarctic Peninsula as Functions of Salinity and Temperature Variations

Temperature and salinity are some of the most influential abiotic parameters shaping biota in aquatic ecosystems. In recent decades, climate change has had a crucial impact on both factors—especially around the Antarctic Peninsula—with increasing air and water temperature leading to glacial melting and the accompanying freshwater increase in coastal areas. Antarctic soft and hard bottoms are typically inhabited by microphytobenthic communities, which are often dominated by benthic diatoms. Their physiology and primary production are assumed to be negatively affected by increased temperatures and lower salinity. In this study, six representative benthic diatom strains were isolated from different aquatic habitats at King George Island, Antarctic Peninsula, and comprehensively identified based on molecular markers and morphological traits. Photosynthesis, respiration, and growth response patterns were investigated as functions of varying light availability, temperature, and salinity. Photosynthesis−irradiance curve measurements pointed to low light requirements, as light-saturated photosynthesis was reached at <70 µmol photons m−2 s−1. The marine isolates exhibited the highest effective quantum yield between 25 and 45 SA (absolute salinity), but also tolerance to lower and higher salinities at 1 SA and 55 SA, respectively, and in a few cases even <100 SA. In contrast, the limnic isolates showed the highest effective quantum yield at salinities ranging from 1 SA to 20 SA. Almost all isolates exhibited high effective quantum yields between 1.5 °C and 25 °C, pointing to a broad temperature tolerance, which was supported by measurements of the short-term temperature-dependent photosynthesis. All studied Antarctic benthic diatoms showed activity patterns over a broader environmental range than they usually experience in situ. Therefore, it is likely that their high ecophysiological plasticity represents an important trait to cope with climate change in the Antarctic Peninsula.