• ALGAE
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• v.21 no.4
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• pp.417-423
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• 2006

Morphology and molecular phylogeny of a red algal species, Hypnea flexicaulis that is recently described from Japan, were investigated based on 23 collections from Korea (21), Taiwan (1), and the Philippines (1). Hypnea flexicaulis has percurrent axes with flexuous, antler-like branches which have wide branching angles, and abaxially curved ultimate branchlets. In order to study DNA divergence and phylogenetic relationships of the species, we determined plastid rbcL and mitochondrial cox1 sequences from the 23 collections. All 21 specimens from five different locations in Korea were almost identical to H. flexicaulis from Japan in rbcL sequences. Although there was a difference of three to five base pairs (bp) between samples from Korea and the Philippines or between the Philippines and Taiwan, Bayesian analyses of the rbcL data showed that all specimens from Korea, Japan, the Philippines, and Taiwan were strongly monophyletic. However, it is interesting that specimens from the Philippines differed by 31-34 base pairs in mitochondrial cox1 gene from those of materials from Korea and Taiwan, which differed by one to seven bp in rbcL between them. Although H. boergesenii is different from H. flexicaulis in having many antler-like branchlets, both appeared as sisters in all analyses of the rbcL data. This is the first report of H. flexicaulis from Korea based on morphology, rbcL, and cox1 gene sequences.

• ALGAE
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• v.21 no.1
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• pp.91-101
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• 2006

Despite continued studies on red algal flora in Korea, the taxonomy of the tiny ceramiaceous algae has received little attention. We report for the first time Griffithsia okiensis from Korea on the basis of morphology and molecular data. The species is small in thalli height (0.3-1.5 cm), and in diameter of vegetative cells (50-500 μm), and the ratio of cell length/breadth is 2-3 times. It has two carpogonial branches from the supporting cell of procarp. We generated psbA and rbcL sequences from ten specimens of G. okiensis isolated from Korea and Japan and from one G. japonica species isolated Japan. Eight specimens of G. okiensis from Korea were almost identical in both psbA and rbcL regions, nevertheless they differed from Japanese specimens by 4 ucleotides in psbA and 7 in rbcL. In all analyses of psbA, rbcL, and psbA + rbcL data sets, G. okiensis was determined to be a different species from G. japonica isolated from Japan, although both species showed a sister relationship. For all that extensive collection trips, we found no evidence for the occurrence of G. japonica in Korea.

• ALGAE
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• v.20 no.2
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• pp.91-97
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• 2005

The brown algal family Chordariaceae sensu lato is a focus of taxonomy because recent studies suggest a broad concept of the family, including genera formerly classified in the Dictyosiphonales. Using morphology, plastid rbcL and nrDNA ITS sequences, we evaluated relationships of the monotyic genus Soranthera (S. ulvoidea), which has been classified in the Punctariaceae. The species occurs in Bering Sea and Aleutian Islands, Alaska to Baja California. Thalli are globose to lobed, hollow, 3-5 cm in diameter, and covered with evenly distributed sori. However, two forms within the species are recognized: f. ulvoidea for globose forms and f. difformis for lobed forms. Plastid rbcL and nuclear ITS region sequences were newly determined in samples of S. ulvoidea from the Pacific coast of the North America. We found little variations in the ITS sequences among samples of S. ulvoidea from five different locations and in the rbcL region from two different locations. These results do not support previous classification of f. ulvoidea and f. difformis within the species. All analyses of our rbcL sequence dataset show that Soranthera was placed in the Chordariaceae s.l., but more related to Botrytella than Punctaria and Asperococcus.

• ALGAE
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• v.29 no.3
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• pp.183-195
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• 2014

There are recognized three new species of Polysiphonia sensu lato at a 10-20 m water depth from Jeju Island, Korea. We described the morphology of three new species and analyzed rbcL sequences to infer phylogenetic relationships among Polysiphonia sensu lato. Polysiphonia amplacapilli sp. nov. is characterized by an epiphytic, discoid holdfast, 5-7 pericentral cells, large trichoblasts, lateral branches connecting with trichoblasts, only slightly corticated in the basal parts, cut-off rhizoids and a spiral arrangement of tetrasporangia. Polysiphonia morroides sp. nov. is characterized by saxicolous, cut-off rhizoids, four pericentral cells, ecorticate, spiral arrangement of tetrasporangia, and it was collected at the fast-flowing water habitat in 20-25 m depth. Polysiphonia sabulosia sp. nov. is characterized by ecorticate, 5-6 pericentral cells, a single filamentous trichoblast, lateral branches connecting with the trichoblasts, cut-off rhizoids, and spiral arrangement of tetrasporangia, and is growing in the sandy locations. The phylogenetic analysis of rbcL sequences demonstrated that three new species are clearly distinguished from other species of Polysiphonia sensu lato.

• ALGAE
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• v.20 no.1
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• pp.15-23
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• 2005

Polysiphonia pacifica is rhodomelaceous red algal species that includes five varieties in Pacific Ocean: P. pacifica var. delicatula, P. pacifica var. distans, P. pacifica var. determinata, P. pacifica var. disticha, and P. pacifica var. gracilis. We here report morphology and phylogeny of P. pacifica to confirm the relationships among previously described varieties as a loan of type specimens from US and to assess phylogenetic relationships of closely related species using plastid protein-coding rbcL gene. Polysiphonia pacifica is distinguished by having creeping filaments attached by unicellular rhizoids not cut off by cross walls, four pericentral cells, ecorticate, trichoblasts rare, ultimate branchlets attenuate at the tip but not pungent, and tetrasporangia in long straight series in the ultimate branchlets. The protein-coding plastid rbcL gene sequence data show that P. pacifica is distinctly different from the superficially similar species, P. morrowii and P. stricta. However, the rbcL sequences of P. pacifica var. pacifica and var. disticha are identical though they have morphological variation.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.663-671
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• 2015

We report the first finding of Halarachnion parvum and Champia lubrica from Korea based on morphology and the plastid rbcL sequence analyses. H. parvum occurs in the subtidal zone of Munseom, the southern part of Jeju. Thalli have short stipe, and elliptical to ovate fronds with marginal proliferations of up to 3 cm in height. H. parvum has zonately divided tetrasporangia and cystocarp immersed under the cortical layer. Champia lubrica appears in Namhae, Gyeongnam and Seopseom, Jeju. Thalli are erect, irregularly branched, terete, obtuse apex, up to 3-5 cm high, and have tetrahedrally divided tetrasporangia. Molecular analyses of the plastid rbcL gene reveal that two species are clearly separated from other species of their respective genera. H. parvum is sister with Halarachnion latissimum in 3.1-3.2% sequence divergence, and C. lubrica is closely related to the sample from Japan with 0.2% sequence divergence.

• ALGAE
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• v.28 no.1
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• pp.53-62
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• 2013

Actinotrichia is a calcified galaxauracean red algal genus with temperate and tropical distributions in the Indian and Pacific Oceans. Morphological characteristics, along with rbcL and cox1 sequences, were analyzed from specimens collected in the western Pacific and the Indian Oceans. Both rbcL and cox1 data confirmed the occurrence of A. fragilis, A. robusta, and Actinotrichia sp. in this region. The presence of A. fragilis was verified in tropical Indo-Pacific and temperate northeast Asian waters and was characterized by high genetic diversity. Although A. robusta commonly occurs in the East China Sea, we confirmed its presence on rocks and crustose algae in the subtidal zone of three islands in the Andaman Sea. Actinotrichia sp. was similar to A. calcea in morphology and distribution, but with sufficiently different sequences, thus, additional sampling over the range will enable a more realistic evaluation of its taxonomic status.

• ALGAE
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• v.31 no.4
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• pp.341-349
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• 2016

The red algal genus Amalthea was first described from New Zealand with one species, A. freemaniae. We discovered a new species of Amalthea from Korea, Amalthea rubida sp. nov., and described it based on morphology and rbcL sequences. A. rubida is characterized by a foliose, membranous and soft thallus having loosely arranged anticlinal medullary filaments, much like A. freemaniae, except for a difference of the cortex thickness in the basal part of vegetative structure. In the rbcL phylogenetic analyses, A. rubida formed a clade with A. freemaniae from New Zealand and Halymenia abyssicola from Mexico. A. rubida showed 5.7% interspecific divergence to A. freemaniae and 4.7% to H. abyssicola. Our discovery of A. rubida expands the distribution of Amalthea from the oceanic southwestern Pacific into the continental northwestern. A targeted global study is needed to fully reveal the species diversity and phylogenetic relationships of the genus Amalthea and members of the order Halymeniales.

• ALGAE
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• v.19 no.3
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• pp.175-190
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• 2004

The morphological and molecular characteristics of Pachydictyon coriaceum (Holmes) Okamura (1899) are described. Plants are collected from Korea all year round and have maximum height from August to September. The monthly variability of thallus growth is in the way with that of the seawater temperature. Two types of thallus structures, thick cortical layer tallus type and thin cortical cell layer type, are distinguished according to growing seasons. The habit of Korean plants is also classified into two thallus types, slender type and wide type, based on the length and the width of internodes, but this distinction between two types is not supported by either anatomical or molecular characteristics. P. coriaceum shares typical morphology in branching pattern and morphogenetic processes with the other species of Dictyota: 1) multi-cellular cortical and medullar layer in the partial of thallus, 2) same development of thallus from apical meristem cell, and 3) sub-lineage within Dictyota species lineage in rbcL, psaA and psbA gene sequences analyses. These characteristics lead to propose the new combination of Dictyota coriacea (Homes) I.K. Hwang, H.S. Kim et W.J. Lee, comb. nov.

• ALGAE
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• v.27 no.4
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• pp.259-268
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• 2012

The genus Pterosiphonia is composed of 22 species worldwide and four of these species have been reported in the North-East Asia. In Korea, P. pennata originally described from the Mediterranean Sea has been previously recorded from the southern coast as a widespread species. In order to confirm the same species from Korea and Mediterranean, we observed the morphology of Korean Pterosiphonia specimen and analyzed rbcL sequences for inferring phylogenetic relationships among similar congeners. Korean entity was recognized as a new species, Pterosiphonia arenosa sp. nov. The new species is characterized by ecorticate axes with 7-10 pericentral cells, branches formed every two segments, and coalesced with main axis over 1-1.25 axial segments, and tetrasporangia formed in straight series on determinate branches of the upper parts of erect axes. A phylogenetic analysis of rbcL sequences demonstrated that P. arenosa was distinct from P. pennata found in Spain as well as other species. In conclusion, morphological and molecular sequence data indicated that P. arenosa sp. nov. has been previously misidentified as P. pennata in Korea.