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Journal of Phycology

Masakazu Hoshino, Kazuhiro Kogame
Parthenogenetic development of unfused gametes is commonly observed in laboratory cultures among various brown algal taxa. There is, however, little information on the contribution of parthenogenesis to the reproduction of field populations. In this study, we investigated whether parthenogenesis is present in a sexual population of the isogamous brown alga Scytosiphon with a 1:1 sex ratio. In culture, both female and male gametes showed higher mortality and slower development compared to zygotes. More than 90% of surviving partheno-germlings formed parthenosporophytes irrespective of the culture conditions tested...
January 14, 2019: Journal of Phycology
Sergei Shalygin, I-Shuo Huang, Allen Elle, JoAnn Burkholder, Paul V Zimba
Pleurocapsales are one of the least known groups of cyanobacteria in terms of molecular systematics and biochemistry. Considering the high number of cryptic taxa within the Synechococcales and Oscillatoriales, it is likely that such taxa also occur in the Pleurocapsales. The new genus described in our research is the first known pleurocapsalean cryptic taxon. It produces off-flavor and a large number of bioactive metabolites (n=38) some of which can be toxic including four known microcystins. Using a polyphasic approach, we propose the establishment of the genus Odorella with the new species O...
January 14, 2019: Journal of Phycology
Michaela E Larsson, Kirsty F Smith, Martina A Doblin
Environmental variables such as temperature, salinity and irradiance are significant drivers of microalgal growth and distribution. Therefore, understanding how these variables influence fitness of potentially toxic microalgal species is particularly important. In this study, strains of the potentially harmful epibenthic dinoflagellate species Coolia palmyrensis, C. malayensis and C. tropicalis were isolated from coastal shallow water habitats on the east coast of Australia and identified using the D1-D3 region of the large subunit (LSU) ribosomal DNA (rDNA)...
January 11, 2019: Journal of Phycology
Shikun Yu, Ying Liu, Jian Zhang, Baoyu Gao
Antibiotics regulate various physiological functions in cyanobacteria and may interfere with the control of cyanobacterial blooms during the application of algaecides. In this study, Microcystis aeruginosa was exposed to H2 O2 and glyphosate for seven days in the presence of coexisting mixed antibiotics (amoxicillin, spiramycin, tetracycline, ciprofloxacin and sulfamethoxazole) at an environmentally relevant concentration of 100 ng · L-1 . The mixed antibiotics significantly (p<0.05) alleviated the growth inhibition effect of 15-45 μM H2 O2 and 40-60 mg · L-1 glyphosate...
January 11, 2019: Journal of Phycology
Przemysław Dąbek, Matt P Ashworth, Ewa Górecka, Marta Krzywda, Thomas G Bornman, Shinya Sato, Andrzej Witkowski
New molecular and morphological insights are presented on Campylosira africana and two new species, Extubocellulus cupola sp. nov. and Plagiogrammopsis castigatus sp. nov. Species descriptions were based on LM/SEM micrographs and a dataset with concatenated sequences of SSU, rbcL and psbC loci constructed from 56 cymatosiroid strains isolated from global geographic locations. Extubocellulus cupola is distinguished by a mesh-like marginal ridge and dome-shaped areolation, and P. castigatus sp. nov., by a prominent marginal extension at the valve center...
January 7, 2019: Journal of Phycology
Tatyana Darienko, Thomas Pröschold
Chlorella-like coccoid green algae are widely distributed in almost all terrestrial habitats and belong to different lineages of the Chlorophyceae and Trebouxiophyceae. The Watanabea clade of the Trebouxiophyceae shows a high genetic biodiversity. Re-investigation of the authentic strain of the rarely found W. reniformis showed several morphological differences compared to the original description. To clarify the taxonomic status of Watanabea, we compared several new isolates with similar morphology. Phylogenetic analyses of the SSU and SSU+ITS rDNA sequences revealed that all new isolates were distinct from W...
December 24, 2018: Journal of Phycology
Andrés Meynard, Javier Zapata, Nicolás Salas, Claudia Betancourtt, Gabriel Pérez-Lara, Francisco Castañeda, María Eliana Ramírez, Cristian Bulboa Contador, Marie-Laure Guillemin, Loretto Contreras-Porcia
A recent molecular taxonomic study along the Chilean coast (18° S-53° S) described 18 candidate species of bladed Bangiales of which only two were formally described. Few studies focused on local genetic and morphological diversity of bladed Bangiales and attempted to determine their intertidal distribution in contrasting habitats; and none were performed in Chile. To delimit intertidal distributions of genetic species, 66 samples of bladed Bangiales were collected at Maitencillo (32° S) in four zones: a rocky platform, a rocky wall, and two boulders zones surrounded by sandy and rocky bottoms, respectively...
December 20, 2018: Journal of Phycology
Maria Orfanoudaki, Anja Hartmann, Ulf Karsten, Markus Ganzera
Rhodophyta produce a variety of chemically different mycosporine-like amino acids (MAAs), compounds that are known as some of the strongest ultraviolet (UV) absorbing molecules in nature. Accordingly, they primarily act as photoprotectants against harmful levels of solar ultraviolet radiation in the UV-A and UV-B range. In order to get a deeper understanding of the chemical diversity of MAAs in red algae, pure standards of eleven mycosporine like-amino acids were isolated from three different species (Agarophyton chilense, Pyropia plicata and Champia novae-zelandiae) using various chromatographic methods...
December 19, 2018: Journal of Phycology
Craig W Schneider, Thea R Popolizio, Gary W Saunders
A molecular survey of red algae collected by technical divers and submersibles from 90 m in the mesophotic zone off the coast of Bermuda revealed three species assignable to the Kallymeniaceae. Two of the species are representative of recently described genera centered in the western Pacific in Australia and New Zealand, Austrokallymenia and Psaromenia and the third from the Mediterranean Sea and the eastern Atlantic, Nothokallymenia. A phylogenetic analysis of concatenated mitochondrial (COI-5P) and chloroplast (rbcL) genes, as well as morphological characteristics, revealed that two are shown to be new species with distant closest relatives (N...
December 19, 2018: Journal of Phycology
Christina Wirth, Romana Limberger, Thomas Weisse
Using microcosm experiments, we investigated the interactive effects of temperature and light on specific growth rates of three species each of the phytoplanktonic genera Cryptomonas and Dinobryon. Several species of these genera play important roles in the food web of lakes and seem to be sensitive to high water temperature. We measured growth rates at three to four photon flux densities ranging from 10-240 μmol photon · m-2 · s-1 and at 4-5 temperatures ranging from 10-28°C. The temperature × light interaction was generally strong, species specific and also genus specific...
December 16, 2018: Journal of Phycology
Eric D Salomaki, Christopher E Lane
Parasitism is a life strategy that has repeatedly evolved within the Florideophyceae. Historically, the terms adelphoparasite and alloparasite have been used to distinguish parasites based on the relative phylogenetic relationship of host and parasite. However, analyses using molecular phylogenetics indicate that nearly all red algal parasites infect within their taxonomic family, and a range of relationships exist between host and parasite. To date, all investigated adelphoparasites have lost their plastid, and instead, incorporate a host derived plastid when packaging spores...
December 9, 2018: Journal of Phycology
Richard Wetherbee, Christopher J Jackson, Sonja I Repetti, Lesley A Clementson, Joana F Costa, Allison van de Meene, Simon Crawford, Heroen Verbruggen
A marine, sand-dwelling, golden-brown alga is described from clonal cultures established from a high intertidal pool in southeastern Australia. This tiny, unicellular species, which we call the "golden paradox" (Chrysoparadoxa australica gen. et sp. nov.), is benthic, surrounded by a multilayered cell wall and attached to the substratum by a complex adhesive plug. Each vegetative cell gives rise to a single, naked zoospore with heterokont flagella that settles and may become briefly amoeboid prior to dividing...
December 9, 2018: Journal of Phycology
Roseanna M Crowell, James A Nienow, A Bruce Cahoon
Nitzschia palea is a common freshwater diatom used as a bioindicator because of its tolerance of polluted waterways. There is also evidence it may be the tertiary endosymbiont within the "dinotom" dinoflagellate Durinskia baltica. A putative strain of N. palea was collected from a pond on the University of Virginia's College at Wise campus and cultured. For initial identification, three markers were sequenced - nuclear 18S rDNA, the chloroplast 23S rDNA and rbcL. Morphological characteristics were determined using light and scanning electron microscopy; based on these observations the cells were identified as N...
December 9, 2018: Journal of Phycology
Jan Kollár, Eveline Pinseel, Meise Belgium, Pieter Vanormelingen, Aloisie Poulíčková, Caroline Souffreau, Petr Dvořák, Wim Vyverman
Diatoms are one of the most abundant and arguably the most species-rich group of protists. Diatom species delimitation has been often based exclusively on the recognition of morphological discontinuities without investigation of other lines of evidence. Even though DNA sequences and reproductive experiments have revealed several examples of (pseudo)cryptic diversity, our understanding of diatom species boundaries and diversity remains limited. The cosmopolitan pennate raphid diatom genus Pinnularia represents one of the most taxon-rich diatom genera...
December 7, 2018: Journal of Phycology
Linan Zhang, Jinku Li, Hao Wu, Yingxia Li
Saccharina japonica undergoes an alternating life cycle during which the diploid sporophyte generation alternates with the monoploid gametophyte generation. Saccharina japonica uses the UV sex determination system to determine the sex of its haploid gametophytes. However, the sex-determining genes and the sex-determining mechanisms of kelp gametophytes have not been thoroughly elucidated to date. In this study, a kelp HMG-box-containing gene (SjHMG), which is located within the sex determination region (SDR) of S...
December 5, 2018: Journal of Phycology
Christopher J T Mabin, Craig R Johnson, Jeffrey T Wright
Temperate kelp forests (Laminarians) are threatened by temperature stress due to ocean warming and photoinhibition due to increased light associated with canopy loss. However, the potential for evolutionary adaptation in kelp to rapid climate change is not well known. This study examined family-level variation in physiological and photosynthetic traits in the early life-cycle stages of the ecologically important Australasian kelp Ecklonia radiata and the response of E. radiata families to different temperature and light environments using a family x environment design...
December 2, 2018: Journal of Phycology
Jeffrey K Y Low, Jenny Fong, Peter A Todd, Loke Ming Chou, Andrew G Bauman
Temporal and spatial variations in Sargassum ilicifolium thallus density and length were investigated on equatorial coral reefs in Singapore from November 2011 to October 2012. Thalli density varied little throughout the year, however, we found strong seasonal patterns in thallus length and identified temperature as the significant driver. S. ilicifolium reached maximum length in December (110.39 ± 2.37 cm) during periods of cooler water temperatures, and minimum length in May (9.88 ± 0.48 cm) during periods of warmer water temperatures...
December 2, 2018: Journal of Phycology
Romana Bacova, Borivoj Klejdus, Pavel Ryant, Natalia Cernei, Vojtech Adam, Dalibor Huska
Epigenetic changes are important mechanisms in the regulation of chromatin structure and gene expression. Cytosine methylation is one of the major epigenetic modifications, mediated by DNA methyltransferases, which transfer methyl groups from S-adenosyl-L-methionine (SAM) to the fifth carbon of cytosine. Various external environmental conditions can change the global hypo/hypermethylation pattern of DNA. These alterations may affect the organism's response to stress conditions. In this study, for the first time, we investigated the effects of 5-azacytidine, a DNA methyltransferase inhibitor, and cadmium, a toxic metal and environmental pollutant, on the growth, biosynthesis of secondary metabolites (phenols, flavonoids, carotenoids), SAM, S-adenosylhomocysteine, 5'-methylthioadenosine and global 5-methylcytosine (5-mC) in the green microalgae Chlamydomonas reinhardtii and Scenedesmus quadricauda...
December 2, 2018: Journal of Phycology
Michala Klimešová, Fabio Rindi, Pavel Škaloud
Mats of the green alga Trentepohlia, a genus widely distributed in the tropics as well as temperate regions, have always been perceived as homogeneous (i.e., formed by only one species). As such, their general nature and specific feature play a supportive role in the species delimitation. However, a presence of morphologically dissimilar thalli was observed under the light microscope and when cultivating a piece of a single mat. To address this, we performed DNA cloning of the rbcL gene on mat fragments of T...
November 27, 2018: Journal of Phycology
Brady R Cunningham, Matthew J Greenwold, Eric M Lachenmyer, Kristin M Heidenreich, Abigail C Davis, Jeffry L Dudycha, Tammi L Richardson
Phenotypic traits associated with light capture and phylogenetic relationships were characterized in 34 strains of diversely pigmented marine and freshwater cryptophytes. Nuclear SSU and partial LSU rDNA sequence data from 33 of these strains plus an additional 66 strains produced a concatenated rooted maximum likelihood tree that classified the strains into 7 distinct clades. Molecular and phenotypic data together support: 1) the reclassification of Cryptomonas irregularis NIES 698 to the genus Rhodomonas, 2) revision of phycobiliprotein (PBP) diversity within the genus Hemiselmis to include cryptophyte phycocyanin (Cr-PC) 569, 3) the inclusion of previously unidentified strain CCMP 2293 into the genus Falcomonas, even though it contains cryptophyte phycoerythrin 545 (Cr-PE 545), and 4) the inclusion of previously unidentified strain CCMP 3175, which contains Cr-PE 545, in a clade with PC-containing Chroomonas species...
November 23, 2018: Journal of Phycology
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