• ALGAE
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• v.19 no.2
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• pp.91-105
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• 2004

Ten taxa of the genus Spirogyra (Zygnemataceae, Chlorophyta) in Korea were examined for morphology and taxonomic category with field as well as cultured materials: S. africana (Fritsch) Czurda, S. decimina (Muller) Kutzing, S. distenta Transeau, S. dubia Kutzing, S. ellipsospora Transeau, S. ellipsospora var. crassoidea Transeau, S. gracilis (Hassall) Kutzing, S. submajuscula Kutzing, S. peipingensis Jao and S. variformis Transeau. Features of vegetative cell and female gametangium, shape of septum, chloroplast number, sexuality, size and shape of zygospore, and ornamentation of spore wall were major characteristics used for determination of the species. All of them were described for the first time in Korea.

• ALGAE
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• v.24 no.2
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• pp.57-60
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• 2009

We described a freshwater filamentous zygnematacean species, Zygnema cruciatum (Vaucher) Agardh in Korea,based on light microscopy and scanning electron microscopy. Zygnema cruciatum is characterized by unbranched fil-amcnts of short cylindrical cells, two stellate chloroplasts per cell, a pyrenoid in each chloroplast. Cells are 32-39 $\mu$m in width and 35-50 $\mu$m in length, Conjugation is scalariform and female gametangia are cylindrical or slightlyenlarged. Zygospores are yellow-brown, spherical or broadly ovoid, 35-44 $\mu$m wide and 40-47 $\mu$m long. Under SEM, wall of zygospore has pitted mesospore and pits are 1.4-1.8 $\mu$m in diameter and 3-4 $\mu$m apart from each other.

• Journal of Ecology and Environment
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• v.38 no.4
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• pp.611-618
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• 2015

Spirogyra is a zygnematalean green algal genus that is ubiquitous in a broad range of freshwater habitats throughout the world. Samples collected throughout Korea from October 2004 to July 2015 were examined using light microscopy. Morphological characteristics (e.g., size of vegetative cells, number of chloroplasts in each cell, type of end walls of adjacent cells, details of conjugation, shape of female gametangia, dimensions and shape of zygospores, color and ornamentation of median spore walls) were used as diagnostic characteristics for species identification. In this study, five species of Spirogyra (i.e., S. emilianensis Bonhomme, S. jaoensis Randhawa, S. pascheriana Czurda, S. weberi var. farlowii (Transeau) Petlovany, and S. weberi var. grevilleana (Hassall) Kirchner) were described as newly recorded in Korea.

• ALGAE
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• v.27 no.4
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• pp.225-234
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• 2012

Zygnema is a conjugating filamentous green algal genus that is distributed in a broad range of freshwater habitats, from sea level to alpine summits. Although more than 150 species have been described worldwide, their taxonomy remains unclear, probably owing to their relatively simple morphology. We investigated the detailed morphology of Korean Zygnema species, combined with analysis of the plastid psbA gene from 22 specimens of the genus and putative relatives, in order to develope a key to their identification and isolation, and to determine their relationships. We recognized two species of Zygnema; Z. insigne and Z. leiospermum, based on morphological characters such as width of the vegetative cell, position of zygospores, dimensions and form of spores, shape of female gametangia, and color of mesospores. The analysis of psbA data was consistent with morphological comparison. The pairwise divergence between two species was 3.7-4.1% (34-38 bp) in psbA sequences. The phylogeny of psbA revealed the monophyly of Z. insigne and Z. leiospermum together with two isolates of Z. circumcarinatum from Germany and Scotland. This is the first report on the psbA gene phylogeny of Zygnema.

• ALGAE
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• v.24 no.1
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• pp.39-45
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• 2009

The conjugation processes of a filamentous freshwater green alga Spirogyra varians were examined using FITC-lectins. Conjugation comprised five steps: 1) aligning with adjacent filaments, 2) formation of conjugation protru-sion (papilla), 3) fusion of the protrusions, 4) formation of conjugation tube,and 5) formation of zygotes. Three lectins, ConA, RCA and UEA, showed considerable labeling during the progression of conjuation. FITC-ConA labeled the surfaces of filaments throughout the whole conjugation processes. FITC-RCA labeling was observed at the conjugation protrusions only after the papilla formation. Strong labeling continued until formationg of zygotes at the contacting area where the conjugation tube developed, but no labeling was detected on the surface of vegetative filaments. The labeling decreased gradually over time and disappeared when zygotes were formed. FITC-UEA showed similar labeling pattern with FITC-RCA except that weak labeling remained after zygote formation. Inhibition experiments using RCA, UEA which are complementary to sugars L-fucose and D-galactose, showed considerable decrease of conjugation (<32% vs. 70% in control). These results suggested that the lectin-carbohydrate recognition system might be involved in the conjugation of spirogyra varians.