• ALGAE
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• 제31권2호
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• pp.105-115
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• 2016

The genus Pterosiphonia includes twenty-one currently described species of red algae that occur in temperate to tropical regions of the Atlantic and Pacific Oceans. Pterosiphonia spinifera was originally described as Polysiphonia spinifera from Peru and later transferred to Pterosiphonia. Pterosiphonia spinifera has been reported from Peru as Pterosiphonia pennata, which was originally described from the Mediterranean Sea. Recently, Pterosiphonia arenosa was described based on specimens of P. pennata from Korea. We collected P. spinifera along the coast of Peru and P. arenosa near the type locality in Korea. We compared them with the isotype specimens of P. arenosa using both morphological and molecular data. Our morphological observations and our phylogenetic analysis of rbcL sequences demonstrate that P. spinifera and P. arenosa are conspecific and indicate that P. arenosa is a later synonym of P. spinifera. Our study confirms the wide occurrence of P. spinifera in the western and eastern Pacific Ocean.

• ALGAE
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• 제25권3호
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• pp.105-113
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• 2010

A new red algal parasite, Symphyocolax koreana M. S. Kim, gen. et sp. nov., has been found on a specimen of Symphyocladia latiuscula (Harvey) Yamada, a member of the tribe Pterosiphonieae of the Rhodomelaceae; this genus has never before been reported to host red algal parasites. Here, the new parasite from Korea is described in terms of vegetative and reproductive morphology. The thallus has a minute, colored polysiphonous upright axis with many branches attached by pseudoparenchymatous pulvinate bases. There are six pericentral cells, with many corticated cells in the lower part of the main branches. Trichoblasts occur on dioecious male and female gametophytes, but not on tetrasporophytes. Procarps develop on suprabasal cells of trichoblasts and consist of a four-celled carpogonial branch and two sterile cells attached to the supporting cell. Spermatangial branches are borne one per each successive segment on monosiphonous pedicels in spiral positions with fertile trichoblast. Tetrasporangia are formed one per segment in a straight series and are tetrahedrally divided. Features of the vegetative axes, procarp, spermatangial trichoblasts, and tetrasporangial branching show that the new genus is an alloparasite belonging to the tribe Polysiphonieae.

• ALGAE
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• 제34권3호
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• pp.187-198
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• 2019

The exploration of seaweed diversity in poorly studied habitats has often led to the discovery of new species. Sand-covered rocks are an example, as they received less attention than sand-free rocky intertidal habitats during seaweed diversity surveys in Brazil. In sand-covered rocks from Espirito Santo and Rio de Janeiro we found an alga whose morphology was unique among rhodomelacean species previously reported in Brazil. With the aim to clarify the taxonomic identity of this species we studied its morphology, as well as its phylogenetic relationships. Molecular analyses resolved this species in the genus Alsidium (tribe Alsidieae) and differed from sequenced congeners with divergences ${\geq}2.5$ and 4.2% in the rbcL and cox1 genes, respectively. Morphological characters were in agreement with the genus Alsidium, and differed from other species currently recognized in the genus. The species consisted of a basal crust and scarcely branched erect axes with seven pericentral cells covered by a continuous layer of cortical cells. Reproductive structures were formed on clusters of short determinate branches. Therefore, the new species A. oliveiranum is proposed based on morphological and molecular evidence. Our findings contribute to better understand the diversity of the tribe Alsidieae, which is particularly diverse in the Americas.

• ALGAE
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• 제21권3호
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• pp.323-332
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• 2006

Mitochondrial distribution and abundance were assessed during the growth of apical and subapical cells in the red algae Colaconema caespitosum (J. Agardh) Jackelman, Stegenga and Bolton and Antithamnion cruciatum (C. Agardh) Nägeli after staining with 3,3’-dihexyloxacarbocyanine iodide [DiOC6(3)] and 2,4’-dimethylaminostyryl-Nethylpyridinium iodide (DASPEI). In fully elongate apical cells of C. caespitosum there were 100-120 mitochondria. During apical cell enlargement and division there is a doubling and then halving of the mitochondrial numbers. Apical cells prior to cytokinesis in young filaments are smaller than in mature filaments (ca. 50 and 100 μm long, respectively) and have fewer mitochondria (ca. 100 and 120 mitochondria per cell, respectively). In older vegetative cells mitochondria tend to aggregate at opposite ends of the cells with some mitochondria associated with the central nucleus or at points of apparent branch initiation. There is a greater density of mitochondria in apical cells of smaller versus larger plants (one mitochondrion per 6.3 μm3 and 9.8 μm3, respectively), suggesting that apical cells of younger plants may be more metabolically active. Male and female gametophytic thalli of Antithamnion cruciatum had similar numbers of mitochondria in apical cells of indeterminate axes, as did gametophytic and sporophytic thalli. There were about 40-50 mitochondria in fully elongated apical cells with about half this number in newly divided apical and subapical cells. Apical cells of determinate branches had more mitochondria (60-77) than indeterminate branches (60-70 vs. 40-50). In both species and in all cell types mitochondrial numbers were highly correlated with cell size.

• ALGAE
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• 제36권2호
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• pp.137-146
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• 2021

Intertidal macroalgae are regularly exposed to hypo- or hypersaline conditions which are stressful. However, red algae in New Zealand are generally poorly studied in terms of salinity tolerance. Consequently, two native (Bostrychia arbuscula W. H. Harvey [Ceramiales], Champia novae-zelandiae [J. D. Hooker & Harvey] Harvey [Rhodymeniales]) and one introduced red algal taxon (Schizymenia spp. J. Agardh [Nemastomatales]) were exposed for 5 days in a controlled salt stress experiment to investigate photosynthetic activity and osmotic acclimation. The photosynthetic activity of B. arbuscula was not affected by salinity, as reflected in an almost unchanged maximum quantum yield (F_v/F_m). In contrast, the F_v/F_m of C. novae-zelandiae and Schizymenia spp. strongly decreased under hypo- and hypersaline conditions. Treatment with different salinities led to an increase of the total organic osmolyte concentrations with rising salt stress in B. arbuscula and Schizymenia spp. In C. novae-zelandiae the highest organic osmolyte concentrations were recorded at S_A 38, followed by declining amounts with further hypersaline exposure. In B. arbuscula, sorbitol was the main organic osmolyte, while the other taxa contained floridoside. The data presented indicate that all three red algal species conspicuously differ in their salt tolerance. The upper intertidal B. arbuscula exhibited a wide salinity tolerance as reflected by unaffected photosynthetic parameters and strong sorbitol accumulation under increasing salinities, and hence can be characterized as euryhaline. In contrast, the introduced Schizymenia spp. and native C. novae-zelandiae, which preferentially occur in the mid-intertidal, showed a narrower salinity tolerance. The species-specific responses reflect their respective vertical positions in the intertidal zone.

• 미생물학회지
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• 제49권1호
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• pp.58-63
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• 2013

본 연구는 한국 제주도 조간대에 서식하는 홍조류로부터 분리된 JIM57 균주의 계통학적 특성을 조사하기 위하여 수행되었다. 16S rRNA gene 염기서열을 분석한 결과, 본 균주는 Oceanisphaera 속과 대단히 유사하였으며, Oceanisphaera litoralis DSM $15406^T$와 98.02%, O. donghaessis KCTC $12522^T$와 97.7%의 염기서열 상동성을 나타내었다. 본 균주는 그람양성의 호기성 구균으로써, 0.5-8.0%의 NaCl 및 $4-47^{\circ}C$에서 생육할 수 있었다. 본 균주는 Oceanisphaera litoralis DSM $15406^T$와 일부 생리학적 및 생화학적 특성을 공유하였으나 ethanol, proline 및 alanine 이용성에서는 차이가 있었다. 본 균주 genomic DNA의 GC 함량은 61.94 mol%였으며, 주요 균체 지방산 지방산으로서 $C_{16:1}$ ${\omega}7c$, iso-$C_{15:0}$ 2-OH, $C_{16:0}$, and $C_{18:1}$ ${\omega}7c$를 함유하고 있었다. 또한 DNA-DNA 상동성을 조사한 결과, JIM57 균주는 O.litoralis DSM $15406^T$ 및 O. donghaessis KCTC $12522^T$와 별개의 종임을 알 수 있었다. 이러한 결과들을 종합한 결과, JIM57 균주(=KCTC 22371 =AM 983543 =CCUG 60764)는 O. litoralis DSM $15406^T$ 및 O. donghaessis KCTC $12522^T$와 다른 특성을 나타내는 것으로 확인되어 Oceanisphaera의 새로운 종임을 제안하였다.