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Journal of Phycology

Sara Usandizaga, Carolina Camus, Jose Luis Kappes, Marie Laure Guillemin, Alejandro H Buschmann
In terrestrial plants, it is well known that genetic diversity can affect responses to abiotic and biotic stress and have important consequences on farming. However, very little is known about the interactive effects of genetic and environmental factors on seaweed crops. We conducted a field experiment on Gracilaria chilensis to determine the effect of heterozygosity and nutrient addition on two southern Chilean farms: Ancud and Chaica. In addition to growth rate and productivity, we measured photosynthetic responses, photosynthetic pigment concentration (chlorophyll a and phycobiliproteins), C:N ratio (C:N), and epiphytic load...
September 17, 2018: Journal of Phycology
Bernabé Santelices, Cristóbal Gallegos Sánchez, Alejandra V González
Genetic diversity is considered a key factor of population survival and evolution, especially in changing environments. Genetic diversity arises from mutations in the DNA sequence of cell lines and from there it reaches the level of organisms, populations, and regions. However, many previous studies have not considered the organism architecture or pattern of thallus construction, ignoring the potential genetic complexities that intra-organismal genetic heterogeneity could generate in modular organisms. In seaweeds, modularity and clonality exist in many species...
September 12, 2018: Journal of Phycology
Yutaro Ando, Toshiya Katano
We investigated shifts in growth rates and cell size reduction-restoration processes in two species of diatoms, Skeletonema japonicum and S. dohrnii. Growth rates greatly fluctuated from 1.0 · d-1 to 2.1 · d-1 , even under the same conditions. Rates increased from 1.1 · d-1 to 2.1 · d-1 with decreasing valve diameter; however, rates quickly decreased to 1.0 · d-1 when cell size reached the threshold for initiating auxosporulation. We also conducted co-culture experiments using different size combinations of the two species...
September 4, 2018: Journal of Phycology
Maria Saburova, Nicolas Chomérat
A new thecate, photosynthetic, sand-dwelling marine dinoflagellate, Laciniporus arabicus gen. et sp. nov., is described from the subtidal sediments of the Omani coast in the Arabian Sea, northern Indian Ocean, based on detailed morphological and molecular data. Cells of L. arabicus are small (16.2-30.1 μm long and 13.1-23.2 μm wide), dorsoventrally compressed, with a small apical flap-shaped projection pointing to the left. The thecal plate pattern is distinguished by minute first precingular plate and sulcus, which extends into the epitheca, with large anterior and right sulcal plates...
September 4, 2018: Journal of Phycology
Merle Regensdorff, Marek Deckena, Maike Stein, Agnes Borchers, Gwydion Scherer, Maike Lammers, Robert Hänsch, Sabine Zachgo, Henrik Buschmann
Mougeotia scalaris is a filamentous streptophyte alga renowned for light-inducible plastid rotation and microtubule-dependent polarity establishment. As a first step towards transgenic approaches we determined the 5825 base pair genomic sequence encoding the α-tubulin1 gene (MsTUA1) of M. scalaris (strain SAG 164.80). The subcloned MsTUA1 promoter facilitated strong transgene expression in M. scalaris and tobacco leaf cells, as shown by particle bombardment and the subsequent visualization of expressed fluorescent protein markers...
September 1, 2018: Journal of Phycology
Zhaohe Luo, Zhangxi Hu, Yingzhong Tang, Kenneth Neil Mertens, Chui Pin Leaw, Po Teen Lim, Sing Tung Teng, Lei Wang, Haifeng Gu
The genus Gymnodinium includes many morphologically similar species, but molecular phylogenies show that it is polyphyletic. Eight strains of Gymnodinium impudicum, Gymnodinium dorsalisulcum and a novel Gymnodinium-like species from Chinese and Malaysian waters and the Mediterranean Sea were established. All of these strains were examined with LM, SEM and TEM. SSU, LSU and internal transcribed spacers rDNA sequences were obtained. A new genus, Wangodinium, was erected to incorporate strains with a loop-shaped apical structure complex (ASC) comprising two rows of amphiesmal vesicles, here referred to as a new type of ASC...
August 25, 2018: Journal of Phycology
Pilar Díaz-Tapia, Christine A Maggs, Erasmo C Macaya, Heroen Verbruggen
Despite studies suggesting that most seaweeds are poor dispersers, many red algal species are reported to have circumglobal distributions. Such distributions have mostly been based on morphological identifications, but molecular data have revealed a range of issues with morphologically defined species boundaries. Consequently, the real distribution of such reportedly circumglobal species must be questioned. In this study, we analyzed molecular datasets (rbcL gene) of nine species in the Rhodomelaceae for which samples were available from widely spaced geographical locations...
August 23, 2018: Journal of Phycology
Sanqiang Gong, Zhiyong Li, Fengli Zhang, Yilin Xiao, Hao Cheng
Light/scanning electron/transmission electron microscopy and multiple nucleotide sequences-based molecular phylogenetic analyses are used to assess the phylogenetic position of a new unidentified green alga isolated from bleached corals living in the South China Sea. This new unidentified green alga is a unicellular marine alga and has uninucleate vegetative cells and multiple chloroplasts with a pyrenoid. It can form aplanosporangium covered by cell walls and reproduces by releasing autospore. These features differ substantially from those of the two genera Ignatius and Pseudocharacium...
August 23, 2018: Journal of Phycology
Prabhakar Singh, Riyazat Khadim, Ankit K Singh, Urmilesh Singh, Priyanka Maurya, Anupam Tiwari, Ravi K Asthana
The objective of the present study was to characterize intrinsic physiological and biochemical properties of the wall-less unicellular cholorophyte Dunaliella salina isolated from a hypersaline Sambhar Lake. The strain grew optimally at 0.5M NaCl and 16:8h L:D photoperiod along with maintaining low level of intracellular Na+ even at higher salinity, emphasizing special features of its cell membranes. It was observed that the cells experienced stress beyond 2M NaCl as evidenced by increased intracellular reactive oxygen species (ROS) and antioxidative enzymes, nevertheless proline and malondialdehyde (MDA) content declined sharply accompanied by higher neutral lipid accumulation...
August 17, 2018: Journal of Phycology
Lauran M Liggan, Patrick T Martone
Maintaining buoyancy with gas-filled floats (pneumatocysts) is essential for some subtidal kelps to achieve an upright stature and compete for light used for photosynthesis. However, as these kelps grow up through the water column, pneumatocysts are exposed to substantial changes in hydrostatic pressure, which could cause complications as internal gases may expand or contract, potentially causing them to rupture, flood, and lose buoyancy. In this study, we investigate how pneumatocysts of Nereocystis luetkeana resist biomechanical stress and maintain buoyancy as they develop across a hydrostatic gradient...
August 11, 2018: Journal of Phycology
Hae Jin Jeong, Ji Hyun You, Kyung Ha Lee, So Jin Kim, Sung Yeon Lee
Gymnodinium smaydae is one of the fastest growing dinoflagellates. However, its population dynamics are affected by both growth and mortality due to predation. Thus, feeding by common heterotrophic dinoflagellates Gyrodinium dominans, Gyrodinium moestrupii, Oblea rotunda, Oxyrrhis marina, and Polykrikos kofoidii, and the naked ciliate Pelagostrobilidium sp. on G. smaydae was investigated in the laboratory. Furthermore, growth and ingestion rates of O. marina, G. dominans, and Pelagostrobilidium sp. on G. smaydae in response to prey concentration were also determined...
August 6, 2018: Journal of Phycology
Kathryn M Schoenrock, Marion Bacquet, Danni Pearce, Brice R Rea, J Edward Schofield, James Lea, Doug Mair, Nicholas Kamenos
In Greenland, free-living red coralline algae contribute to and dominate marine habitats along the coastline. Lithothamnion glaciale dominates coralline algae beds in many regions of the Arctic, but never in Godthåbsfjord, Greenland, where Clathromorphum sp. is dominant. To investigate environmental impacts on coralline algae distribution, calcification and primary productivity were measured in situ during summers of 2015 and 2016, and annual patterns of productivity in L. glaciale were monitored in laboratory-based mesocosm experiments where temperature and salinity were manipulated to mimic high glacial melt...
August 5, 2018: Journal of Phycology
Christian Boedeker, Frederik Leliaert, Oleg A Timoshkin, Vasily S Vishnyakov, Sergio Díaz-Martínez, Giuseppe C Zuccarello
Lake Baikal, the oldest lake in the world, is home to spectacular biodiversity and extraordinary levels of endemism. While many of the animal species flocks from Lake Baikal are famous examples of evolutionary radiations, the lake also includes a wide diversity of endemic algae that are not well investigated with regards to molecular-biological taxonomy and phylogeny. The endemic taxa of the green algal order Cladophorales show a range of divergent morphologies that led to their classification in four genera in two families...
August 4, 2018: Journal of Phycology
Thomas Lines, John Beardall
CO2 levels in freshwater systems can fluctuate widely, potentially influencing photosynthetic rates and growth of phytoplankton. Given the right conditions, this can lead to bloom formation and affect water quality. This study investigated the acquisition of dissolved inorganic carbon (DIC) by six species of microalgae, a cyanobacterium Cylindrospermopsis raciborskii, the diatoms Cyclotella sp., Nitzschia sp., and the green algae Stichococcus sp., Staurastrum sp., and Monoraphidium sp., all isolated from a subtropical reservoir in Australia...
July 28, 2018: Journal of Phycology
Anne Herbst, Wolf von Tümpling, Hendrik Schubert
Encrustation and element content of six charophyte species from two hard-water lakes were investigated monthly for a period of 1 year. Seasonal patterns were analyzed for the interaction of water chemistry. Encrustation followed a seasonal pattern for Chara contraria, Chara subspinosa, and Nitellopsis obtusa in Lake Krüselin and for Chara globularis and Chara tomentosa in Lake Lützlow. However, no seasonality in the precipitated CaCO3 was observed for C. subspinosa in Lake Lützlow and for C. tomentosa in Lake Krüselin, indicating a lake-specific dependency...
July 28, 2018: Journal of Phycology
Chia-Jung Hsieh, Shing Hei Zhan, Chen-Pan Liao, Sen-Lin Tang, Liang-Chi Wang, Tsuyoshi Watanabe, Paul John L Geraldino, Shao-Lun Liu
Extremophilic microalgae are primary producers in acidic habitats, such as volcanic sites and acid mine drainages, and play a central role in biogeochemical cycles. Yet, basic knowledge about their species composition and community assembly is lacking. Here, we begin to fill this knowledge gap by performing the first large-scale survey of microalgal diversity in acidic geothermal sites across the West Pacific Island Chain. We collected 72 environmental samples in 12 geothermal sites, measured temperature and pH, and performed rbcL amplicon-based 454 pyrosequencing...
July 28, 2018: Journal of Phycology
Laura González-Resendiz, Jeffrey R Johansen, Viviana Escobar-Sánchez, Claudia Segal-Kischinevzky, Luis F Jiménez-García, Hilda León-Tejera
Two untapered, heterocytous species were observed and collected from the intertidal and supratidal zones of the Mexican coastline of the Pacific Ocean near Oaxaca and from the Gulf of Mexico. These populations were highly similar in morphology to the freshwater taxon Petalonema incrustans in the Scytonemataceae. However, 16S rRNA sequence data and phylogenetic analysis indicated that they were sister taxa to the epiphyllic, Brazilian species Phyllonema aveceniicola in the Rivulariaceae, described from culture material...
July 28, 2018: Journal of Phycology
Adam Michael Lewis, Lewis Nicholas Coates, Andrew D Turner, Linda Percy, Jane Lewis
Alexandrium minutum is a globally distributed harmful algal bloom species with many strains that are known to produce paralytic shellfish toxins (PSTs) and consequently represent a concern to human and ecosystem health. This review highlights that A. minutum typically occurs in sheltered locations, with cell growth occurring during periods of stable water conditions. Sediment characteristics are important in the persistence of this species within a location, with fine sediments providing cyst deposits for ongoing inoculation to the water column...
July 26, 2018: Journal of Phycology
Niels Daugbjerg, Andreas Norlin, Connie Lovejoy
Twenty years ago an Arctic cryptophyte was isolated from Baffin Bay and given strain number CCMP2045. Here, it was described using morphology, water- and non-water soluble pigments and nuclear-encoded SSU rDNA. The influence of temperature, salinity, and light intensity on growth rates was also examined. Microscopy revealed typical cryptophyte features but the chloroplast color was either green or red depending on the light intensity provided. Phycoerythrin (Cr-PE 566) was only produced when cells were grown under low-light conditions (5 μmol photons · m-2  · s-1 )...
July 25, 2018: Journal of Phycology
Bánk Beszteri, Claire Allen, Gastón O Almandoz, Leanne Armand, María Ángeles Barcena, Hannelore Cantzler, Xavier Crosta, Oliver Esper, Richard W Jordan, Gerhard Kauer, Christine Klaas, Michael Kloster, Amy Leventer, Jennifer Pike, Andrés S Rigual Hernández
Semiautomated methods for microscopic image acquisition, image analysis, and taxonomic identification have repeatedly received attention in diatom analysis. Less well studied is the question whether and how such methods might prove useful for clarifying the delimitation of species that are difficult to separate for human taxonomists. To try to answer this question, three very similar Fragilariopsis species endemic to the Southern Ocean were targeted in this study: F. obliquecostata, F. ritscheri, and F. sublinearis...
July 17, 2018: Journal of Phycology
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