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The freshwater red algal genus Sheathia is one of the most species‐rich genera in the Batrachospermales, containing species with heterocortication (both bulbous and cylindrical cells covering the main axis) and homocortication (only cylindrical cells). The hidden diversity of homocorticated Sheathia species has gained research momentum. Recent studies have revised these taxa and described many new species. In this study, a new homocorticated Sheathia species is described and illustrated from Yunnan, China, based on phylogenetic analyses of DNA sequence data. Sheathia yunnanensis sp. nov is morphologically characterized by having homocortication, carpogonium with bent or slightly constricted lanceolate trichogyne, large carposporophyte and carposporangium. However, it is only distinguishable from other homocorticated species by DNA sequence data. Phylogenetic analyses based on rbcL, COI‐5P, psbA and concatenated rbcL + COI‐5P alignment indicated that Sheathia yunnanensis form an independent clade from other homocorticated Sheathia species with high interspecific divergence (rbcL: 3.9–4.9%/37–54 bp, COI‐5P: 6.1–6.6%/36–39 bp and psbA: 2.2–3.9%/18–32 bp). Sheathia yunnanensis, as the first gametophyte of Sheathia species reported in Yunnan, differs from other Sheathia species reported only as 'Chantransia' sporophyte stage. As a result of this study, the number of Sheathia species recognized in China increased to eight, including one heterocorticate and seven homocorticated including three only known from the 'Chantransia' sporophyte stage. The description of this new species expands the diversity of Sheathia in the world. [ABSTRACT FROM AUTHOR]

Summary: The freshwater red alga Nemalionopsis shawii Skuja is first reported for mainland China from specimens collected in Guangdong and Yunnan Province. Morphological observations and molecular sequences of rbcL and cox1 genes were used to identify and analyze the phylogenetic position of the samples. Samples from China formed a monophyletic clade with other N. shawii samples from Japan, Indonesia, and Nepal with robust support values. The pairwise genetic distances for N. shawii between the samples from China and other samples were 0.2–1.5% and 1.0–2.4% for rbcL and cox1, respectively. Both male and female reproductive structures were observed in the specimens from Guangdong, but only monosporangia in the specimen from Yunnan. The samples from China increase the diversity of morphological measurements for N. shawii. The discovery of this genus in mainland China results in a new record of a freshwater red alga for this country. [ABSTRACT FROM AUTHOR]

Collections of Batrachospermales from 13 stream sites in North America (Canada and United States), Europe (Spain) and Asia (China) were examined. Phylogenetic analyses of sequences data from the plastid-encoded ribulose 1,5-bisphosphate carboxylase/oxygenase large subunit gene ( rbcL) and the mitochondrial-encoded cytochrome oxidase 1 gene barcode region (COI-5P), along with morphological studies, suggested that these collections represent new taxa. Three species in a proposed new genus Volatus are described: V. carrionii sp. nov., V. personatus sp. nov. and V. ulterior sp. nov. Four new species of Batrachospermum sensu stricto are also described: B. dapsile sp. nov., B. naiadis sp. nov., B. pozoazulense sp. nov. and B. shanxiense sp. nov. Taxa proposed based on the molecular analyses were in many cases difficult to distinguish with unique morphological characters. The new genus Volatus shares the distinctive characteristic of twisted or curled carpogonium-bearing branches with Kumanoa and Tuomeya but was not sister to either of these genera, suggesting that this character may have arisen at least three times in the order. The three species of Volatus were distinguished from each other based on molecular data and, in part, geographic distribution. The proposed Batrachospermum species B. naiadis sp. nov., B. pozoazulense sp. nov. and B. shanxiense sp. nov. overlap in both vegetative and reproductive characters with each other and B. gelatinosum. Batrachospermum dapsile had a distinguishing character of monosporangia in clusters arising from the periaxial or proximal cells and terminal or subterminal on primary fascicles. [ABSTRACT FROM AUTHOR]

Parachlorella kessleri TY isolated from the lawn soil belongs to Trebouxiophyceae, Chlorophyta. The complete mitogenome of P. kessleri sequenced and described. It is a circular duplex molecule 64,744 bp in length consisting of 28 protein-coding genes, 23 transfer RNA (tRNA) genes, four ribosomal RNA (rRNA) genes, and one putative open reading frames (ORFs). Phylogenetic analysis places P. kessleri mitogenome in a branch sister to Picochlorum sp., Lobosphaera incisa, and Chloroparvula sp., clade in which Picochlorum as P. kessleri also reported as oil-rich green microalgae. [ABSTRACT FROM AUTHOR]

An enigmatic acrochaetioid alga was collected from Niangziguan spring in Shanxi Province, northern China. Morphological data indicated that this alga reproduces exclusively asexually by monosporangia and its morphological characteristics suggested that it might be referred to Audouinella heterospora. To ascertain its phylogenetic position, phylogenetic trees were reconstructed using partial sequences of the plastid-encoded gene (rbc L) and the nuclearencoded gene (SSU rDNA) applying Bayesian inference (BI), maximum parsimony (MP) and maximum likelihood (ML). However, phylogenetic reconstructions showed that this acrochaetioid alga does not belong in a clade with the genus Audouinella, but forms a clade with Th orea hispida (Th oreales). Based on this analysis it is concluded that A. heterospora represents the 'chantransia' stage of T. hispida. [ABSTRACT FROM AUTHOR]

Parachlorella kessleri TY isolated from the lawn soil belongs to Trebouxiophyceae, Chlorophyta. The complete mitogenome of P. kessleri sequenced and described. It is a circular duplex molecule 64,744 bp in length consisting of 28 protein-coding genes, 23 transfer RNA ( tRNA ) genes, four ribosomal RNA ( rRNA ) genes, and one putative open reading frames (ORFs). Phylogenetic analysis places P. kessleri mitogenome in a branch sister to Picochlorum sp ., Lobosphaera incisa , and Chloroparvula sp., clade in which Picochlorum as P. kessleri also reported as oil-rich green microalgae., Competing Interests: No potential conflict of interest was reported in the author(s)., (© 2021 The Author(s). Published by Informa UK Limited, trading as Taylor & Francis Group.)

In our early experiments, the chloroform extract of D. crassirhizoma was demonstrated to contain the highest concentrations of total phloroglucinols among several extract fractions and possessed the most effective nematicidal activity. This study aimed to ascertain the ultrastructural changes in M. incognita after treatment with a D. crassirhizoma chloroform extract at 1 mg·mL⁻¹ for 24 h. It was found that the extract exhibited significant destructive effects on the worm's ultrastructure and caused distinctive damage to body surfaces and internal structures. These results will contribute to a deeper understanding of the nematicidal mechanism of D. crassirhizoma, as well as in the design of efficient bionematicides.