• ALGAE
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• 제17권1호
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• pp.33-39
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• 2002

Mechanisms of competition between two canopy algae and an understory alga were investigated by a field manipulative experiment using artificial thalli. The study was carried out in the upper intertidal zone at Nudibranch Point in Vancouver Island, British Columbia, Canada, where two fucoids, Fucus gardneri and Pelvetiopsis limitata, and a turf red alga, Mazzaella cornucopiae, were dominant in the algal community. The experiment was designed to test three hypotheses, shading, whiplash, and allelopathy, imposed by potential fucoid effects on M. cornucopiae. Only the shading effect was significant, indicating that adult fucoid thalli reduced. M. cornucopiae biomass underneath the fucoids. Results indicated that reversal of competitive dominance existed between F. gardneri and M. cornucopiae depending on the life history stage of the competitors. By including the turf alga's effects on the fucoids, the well-balanced and non-hierarchical interaction networks among the major macroalgae support the high likelihood of species coexistence in the community.

• Journal of Plant Biology
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• 제37권4호
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• pp.421-428
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• 1994

The vegetative and male reproductive anatomy of a marine alga, Laurencia intercalaris sp. nov. (Rhodomelaceae, Rhodophyta), is described from subtidal habitats of eastern and southern Korea. This species has terete thalli with entangled fibrous holdfasts and regularly alternate branching of ultimate branchlets, and is inseparable from L. okamurae Yamada on the basis of habit. Vegetative axial cells produce a trichoblast and four pericentral cells in an alternating sequence. Spermatangia are produced intercalary or subterminally from one of two laterals on suprabasal cells of trichoblasts arising from axial cells in apical pits of branchlets. The other lateral remains sterile. In this sterile lateral, budding-like regeneration occurs on older segments that are oabscised. Comparison is made with other related Laurencia species, particularly those with terete thalli. The vegetative anatomy and the regeneration in sterile laterals of male trichoblasts, with the mode of spermatangial formation, distinguish the new species from previously described species of Laurencia including L. okamurae.

• 환경생물
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• 제35권4호
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• pp.521-525
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• 2017

A marine algal species belonging to Gigartinales was collected from Geoje, Korea. This shares the generic features of Ahnfeltiopsis, such as multiaxial thalli with a compact and pseudoparenchymatous medulla, densely cytoplasmic secondary medullary cells around immersed cystocarps with a carpostome, and is distinct from similar species within the genus by a combined feature of small (up to 4 cm tall) and tuft thalli, compressed to subcompressed branches except for ultimate branchlets and base of main axes, cartilaginous in texture, dichotomous branches, rarely produced proliferations, absence of hypha-like filament in the medulla and internal cystocarps with a carpostome. In phylogenetic tree based on rbcL sequence, the Korean species nests in the same clade with Ahnfeltiopsis linearis. The genetic distance between both sequences within the clade was 1.5%, considered to be within the intra-species range for the genus. This morphological and molecular evidence confirms the Korean alga to be identified as A. linearis originally described from California. This is the first record of A. linearis in Korea.

• Fisheries and Aquatic Sciences
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• 제1권1호
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• pp.122-128
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• 1998

Characteristic changes in chlorophyll fluorescence from thalli of red alga, Porphyra, under high salt stress and during subsequent recovery were investigated, and the differences in the sensitivity to the stress among four species of Porphyra with different intertidal distributions were compared. By the treatment of NaCl with $9\%$ or higher concentrations, photochemical efficiency (Fv/Fm) decreased in a biphasic pattern: a rapid decrease was observed within 1­3 h and followed by a slow decline. The decrease of Fv/Fm was mainly due to the increase of Fo without significant increases of Fm. When the thalli treated with $15\%$ NaCl for 6 h were returned to natural sea water for recovery, the increase of Fv/Fm also showed a biphasic pattern: a rapid increase of Fv/Fm was observed within 2 h and followed by a slow increase. Differences in the sensitivity to salt stress among the four species could be found during recovery after the treatment of severe salt stress. After the treatment of $20\%$ NaCl for 6 h, Fv/Fm decreased below 0.3 in all of the four Porphyra species, and the species living in upper parts of the intertidal zone (P. suborbiculata and P. pseudolinearis) could recover better compared with the species in lower parts of the intertidal zone (P. seriata and P. yezoensis), during recovery for 24 h. The species collected from the coast of the South Sea seemed to be more tolerant than those in the East Sea.

• 한국수산과학회지
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• 제36권3호
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• pp.225-229
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• 2003

Plant ash and soil drainage, derived by frequent mountain fires during winter, might cause biological contamination to seaweeds at seashore and river mouse area. To thalli of Ulva pertusa, maximum non-lethal concentration(MNLC), lethal concentration 50 $(LC_{50})$ and minimum lethal concentration (MLC) of pine needle ash were shown as 60, 350 and 550 mg/mL, respectively. The yellow loess and granite sand did not damage at concentrations of 20 and 200 mg/mL, respectively To thalli of Porphyra yezoensis, the MNLC, LC5O, MLC of pine needle ash were shown as 0.08, 0.4 and 1.0 mg/mL, respectively. Effects of yellow loess and granite sand were approximately 1/2 and 1/10 of the ash. To thalli of Undaria pinnatifida, the pine needle ash, yellow loess and granite sand did not damage at the concentration range of 20 to 40 mg/mL. Change of pigments $(chlorophyll\;\alpha,\;lutein,\;\beta-carotene,\;phycoerthrin)$ was also determined at the MNLC, $LC-{50}$ and MLC of pine needle ash. Among three seaweeds tested, P. yezoensis produced the most 2.7-fold of lutein and 2.3-fold of $\beta-carotene$ at $LC-{50}$ of the ash. Thus the P. yezoensis, appeared as a sensitive indicator, could be used as one of test organisms for determination of the biological effect of pollutants contaminated in marine environment.

• ALGAE
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• 제24권4호
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• pp.249-256
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• 2009

The occurrence of Laminarionema elsbetiae (Ectocarpaceae, Phaeophyceae), as epi-endophyte of Rhodymenia pseudopalmata (Rhodymeniales, Rhodophyta), described from Santa Isabel, Rawson, Argentina. L. elsbetiae grows in the host tissues forming epi-endophytic relationship in the epidermal, cortical and medullar layers. Epiphytic thalli of L. elsbetiae were unbranched filaments emerging from hostis surface. Reproductive structures of L. elsbetiae on the host were absent. On the contrary, free cultured individuals formed different reproductive structures. Macrozoosporangia containing a single large motile zoospore originated from vegetative cells, they were conical to cylindrical in shape, 30-50 ${\mu}m$ in length and 18-20 ${\mu}m$ in wide. Uniseriate plurilocular zoosporangia were cylindrical shape, 40 ${\mu}m$ in length and 10-13 ${\mu}m$ in wide. Sexual fusion was not seen. In mixed cultures of L. elsbetiae with R. pseudopalmata fronds, L. elsbetiae infected the host, grew as in natural host and, formed macrosporangia between host subcortical cells. Gametophytes of L. elsbetiae were filaments with diffuse growth, branched with a branch pattern alternate or opposite. Gametangia were plurilocular, uni or biseriate and lateral. When mature they contained 2 to 6 isogametes. The presence L. elsbetiae on R. pseudopalmata could be defined as an epi-endophytic relationship. The percentage of infection of R. pseudopalmata thalli by L. elsbetiae was 34%.A25% of the infected thalli presented a low, non-symptomatic level infection, whereas a 62% and a 13% of them exhibited respectively moderate and high indexes of infection.

• 한국양식학회지
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• 제4권1호
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• pp.67-71
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• 1991

돌연변이유기를 통한 유용견전형질의 해조류품종을 개발하기 위해 화학적돌연변이유발원인 Ethyl-methanesulphonate(EMS)에 대한 구멍갈파래(Ulva pertusa Kjellman) 엽체의 감수성을 검토하여 효과적인 돌연변이유기조건을 찾고자 하였다. EMS를 처리한 배지에 엽체를 생장시키며 변이를 유발시키고자 하였을 때, $0.05{\%}$와 $0.025{\%}$의 EMS 처리구에서 각각 $100{\%}$와 약 $20{\%}$의 생장억제가 일어났다. 한편 고농도의 EMS액에 엽체를 일정시간 침적한 후 정상배양함으로서 변이를 유발코자 했을 때, $1.0{\%}$ EMS액에 40분과 $0.5{\%}$ EMS액에 80분 처리한 경우 각각 $100{\%}$와 약 $10{\%}$의 생장억제가 일어났다. EMS 처리된 엽체는 생장형과 체색이 모체와 전혀 다른 변이체로 나타나기도 하였는데 이들의 polypeptide 일부에 변화가 있음이 SDS-PAGE로 조사되었다.

• 한국균학회지
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• 제27권3호통권90호
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• pp.208-210
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• 1999

본 연구는 우리나라에서 충생자낭균류의 자원을 발굴하고, 동정하여 새로운 생물자원을 확보하기 위하여 1996년 10월부터 1997년 9월까지 연구한 결과이다. 현재까지 우리나라의 충생자낭균류는 16속 59종이 기록되어 있으며, 본 연구를 통하여 동정된 충생자낭균류의 미기록 3종을 다음과 같이 보고하고자 한다. Laboulbenia anoplogenii Thaxter는 Stenolophys quinquepustulatus Widemann으로부터 발견되었다. 이 균체의 특징은 탁의 4번층의 세포수가 $2{\sim}3$개으로 되어 있으며, 상부를 향하여 돌출하고 있다. Laboulbenia habui Terada는 Chlaenius variicornis Bates에서 채집되었다. 이 종의 특징은 2차 부속지의 기부세포들이 교대로 2열로 배열된 짧은 원통형으로 되어있다. Laboulbenia pallida Thaxter는 Anisodactylus signatus Panzer에서 채집되었다. 이 종은 Harpalus Sp.에서 발견되어 왔지만, Anisodactylus signatus Panzer에서는 처음으로 발견되었다. 이 종의 특징은 자낭각의 정단부가 둥글며, 의부속지는 기부세포에서 가지쳐 있다. 본 연구로 우리나라의 충생자낭균류는 16속 62종이 기록된다.

• 한국양식학회지
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• 제13권4호
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• pp.295-301
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• 2000

1996년 2월 24일 전남 진도에서 채집한 넓은둥근돌김을 엽상체기와 사상체기의 생장, 성숙에 미치는 온도, 광량, 광주기의 영향을 구명하고 둥근돌김과의 생리특성을 비교하고자 수행하였다. 넓은둥근돌김의 엽상체와 사상체는 장.단일하의 5~$25^{\circ}C$에서 생장하며 엽상체는 장일하의 15$^{\circ}C$와 단일하의 10, 15$^{\circ}C$에서 생장과 성숙이 이루어졌고 엽형은 단일하의 1$0^{\circ}C$에서 천연의 조체와 비슷한 폭이 넓은 둥근형으로 되었다. 사상체의 생장은 양광주기하의 2$0^{\circ}C$이상, 40~80${\mu}$mol m$^{-2}$s$^{-1}$의 광량조건에서 빨랐으며, 광주기는 단일조건에 비하여 장일조건이 더 빨랐다. 각포자낭의 형성은 장, 단일하의 15~$25^{\circ}C$에서 나타났으며 각포자낭 형성시기 및 형성률은 단일하의 $25^{\circ}C$에서 빠르고 높게 나타났다. 이상의 결과에서 넓은둥근돌김은 엽상체 및 사상체기에 있어서 둥근돌김과는 다른 생리특성을 갖는 것으로 밝혀졌다. 따라서 넓은둥근돌김은 장일, 고온하의 조건이 5월 이후에도 천연에서 생육 가능성이 높은 것으로 추정되며 하기에도 유아 상태로 여름을 지날 수 있는 가능성이 높은 것으로 시사되었다.

• Journal of Photoscience
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• 제9권2호
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• pp.74-77
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• 2002

Chlorophyll (Chi) d was assigned to an antenna pigment of red algae in 1943, but its presence and function in red algae have not been necessarily clear for a long time. In 1996, it was shown that Chi d functioned as a major antenna pigment in a peculiar oxygenic photosynthetic prokaryote, Acaryochloris marina, isolated as a symbiont of a colonial ascidian from coral reefs. This finding evoked the necessity for reexamination of the presence and function of Chi d in red algae. We found Chi d in methanol-extract from several marine red algae, and the relative content was high in one species, Ahnfeltiopsis flabelliformis. Absorption and fluorescence spectra, HPLC analysis, and NMR and mass spectroscopy characterized Chi d extracted from the red algal thalli, and those were essentially identical to those of Chi d isolated from A. marina. However, micro-spectrophotometric analysis suggested that Chi d was not an actual constituent of the red algae but came from epiphyte(s) attached to surface of red algal thalli.