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Although Strombomonas verrucosa has been the type of the genus name for almost 100 years, its lack of clear diagnostic traits has rendered morphological distinction from its congeners almost impossible. As such, a study was conducted combining previously unused morphological data (chloroplast characters) with molecular data (sequences of nuclear SSU, LSU and plastid‐encoded SSU rDNA) and extensive literature review. The study focused on environmental samples obtained from Poland and China and resulted in 51 new sequences representing three molecular markers (17 nSSU, 16 nLSU and 18 cpSSU rDNA). Revised delimitations of the genus Strombomonas and its type S. verrucosa are presented that include new and detailed diagnostic characters. In addition to the type, we recognize nine species: S. acuminata, S. borystheniensis, S. eurystoma, S. fluviatilis, S. gibberosa, S. maxima, S. ovalis, S. schauinslandii, S. triquetra. Three of these are incorporated into a phylogeny for the first time (S. fluviatilis, S. gibberosa, S. schauinslandii). To improve the efficiency of DNA isolation from loricate cells, a protocol utilising a chelating resin for DNA isolation – following the lead of diatomologists – has been adjusted for Euglenaceae and is also presented. [ABSTRACT FROM AUTHOR]

The classification of Trachelomonas and Strombomonas is based on the morphology of loricae, which may not reflect phylogenetic relationships. There are different views on the relationship between the two genera. It is thus important for researchers to classify the two genera based on more characteristics besides loricae, such as protoplast and molecular data, and to establish a natural classification system. In this study, 29 strains (13 species) of Trachelomonas and 12 strains (eight species) of Strombomonas were collected from various locations in China. The morphological characteristics of Trachelomonas and Strombomonas were observed in the field and culture conditions, and the sequences of nuclear SSU rDNA, nuclear LSU rDNA, plastid-encoded LSU rDNA and plastid-encoded LSU rDNA of strains were obtained. We constructed a phylogenetic tree by combining four gene sequences with maximum likelihood and Bayesian methods. Based on the development of the loricae, it was found that the shape of the loricae and the presence or absence of the collar were relatively stable in culture, while the length of the collar presence or absence of spines and the color of the loricae changed. The phylogenetic tree showed that Trachelomonas and Strombomonas were sister branches, which supported Trachelomonas and Strombomonas as independent genera. Taxa in the genus Strombomonas sorted into two clades and Trachelomonas sorted into five strongly supported clades. Key morphological features could be attributed to each of the clades. [ABSTRACT FROM AUTHOR]

The green alga Prasiola fluviatilis (Sommerfelt) Areschoug ex Lagerstedt occurs in cold lotic environments. The species has a mainly circumarctic distribution, but has also been reported from glacier areas in lower latitude regions in both hemispheres. It was reported from China on a single occasion in the first half of the 20th century, but without description, illustrations or voucher specimens the identity of this record cannot be verified. Here we confirm the presence of P. fluviatilis in the Tianshan Mountains, Xinjiang Province, China based on morphological features, habitat characteristics, and plastid rbcL and tufA gene sequences. The biogeographic distribution of P. fluviatilis and its phylogenetic relationship with other terrestrial and freshwater Prasiola species are discussed. [ABSTRACT FROM AUTHOR]