• Journal of Marine Life Science
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• v.8 no.2
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• pp.160-165
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• 2023

This study describes the light microscopical cell types and histochemical characteristics as a preliminary study for the research on integument of the walleye pollock Gadus chalcogrammus in accordance with the physiological and environmental changes. The lateral line of the integument surface showed a curve in the anterior part and was straight from the middle to the posterior part. Integument is composed of outer epidermis and inner dermis. The epidermis is a stratified layer composed of epithelial cells, mucous cells, and club cells. Epithelial cells are classified into squamous superficial cell, cuboidal intermediated cell and columnar basal cell. The thickness of epidermis was 122.9 ㎛, and the ratio of epidermis thickness to body length was 0.03%. The mucous cell and club cell of unicellular gland were mainly distributed in the apical and middle layer of epidermis. The mucous cell contained mucosal materials of acidic glycoprotein. The proportion of mucous cells and club cells were 21.3 (± 7.0)% and 4.0 (± 1.0)% of epidermal area, respectively. The dermis was dense connective tissue layer and composed of mainly collagen fibers. It also contained fibrocytes, blood vessels, melanophores and scales.

• Horticultural Science & Technology
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• v.33 no.3
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• pp.420-428
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• 2015

The majority of cultivated varieties of grape have perfect flowers that are clustered in an individual inflorescence. Grape flower has a single pistil, five stamens, a protective flower cap (calyptra), and a calyx. After fertilization, an individual flower develops into a single berry. Although there are a number of reported studies focusing on berry formation, berry enlargement, and sugar accumulation in grape, the morphological studies of flower, including gametophyte morphogenesis and structural change in floral organs, have not yet been studied in detail. In this study, we investigated the flower structure and development characteristics of grape using microscopy and defined the floral development stages 9 to 13 based on microspore or male gametophyte development stage from tetrad to mature pollen. We used seeded diploid table grapes 'Campbell Early' (Vitis labruscana) and 'Tamnara' (V. spp.) as plant materials. At floral development stage 9, pollen mother cells develop to tetrads. During floral development stages 10 to 11, unicellular microspore develop to mid bicellular pollen. At the end of floral stage 12, male gametophyte develops to mature tricelluar pollen. In floral stage 13, the flower cap falls off and flower bud opens. During floral development stages 9 to 12, there were no major changes in calyx length, whereas the length of the flower cap continuously increased. The flower cap-to-calyx length ratio was 2.0, 3.0, 4.5, and 6.5 at floral stages 9, 10, 11, and 12, respectively. The flower cap-to-calyx length ratio was consistent in the two grape cultivars, suggesting that the ratio is a morphological character representing floral development stage. This study provides a reference for determining floral development stage of the two grape cultivars. It will be useful for the determination of optimum time for microspore culture needed to generate doubled haploid lines and appropriate gibberellic acid treatment needed to induce parthenocarpic fruit development in 'Tamnara' grape.

• The Korean Journal of Malacology
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• v.24 no.1
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• pp.41-50
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• 2008

The histochemical characteristics and ultrastructure of the mantle in the spiny top shell, Batillus cornutus were described using light and electron microscopy. The simple epidermal layer wrapped on the top and bottom of the centrally located connective tissue. And then the epidermal layer were divided into the outer epidermal layer near a shell and the inner epidermal layer closed to the visceral mass. The connective tissue layer was composed of the collagen fiber muscularfiber bundle and hemolymph sinus. Mucous cells in the apical mantle contained acid and neutral mucopolysaccaride, and acidic carboxylated mucopolysaccaride in the mid and marginal mantle. The mantle thickness, epidermal layer thickness and hemolymph sinus area displayed a trend of reduction from the marginal zone to the apical zone. From TEM observation, it was possible to distinguish epithelium, ciliated cell, absorptive cell and secretory cell in the epidermal layer. The epithelia were columnar and the nucleus was elliptical. The free surface were covered with microvilli. The lateral membranes of epithelium was con nected with neighboring cells by the zonular occludens, zonular adherens and membrane interdigitation. Ciliated cell on free surface had cilia and microvilli, and numerous mitochondria in the apical cytoplasm. In the epidermal layer, it observed 2 type cells having absorptive function. The absorptive cells were columnar in shape, and contained microvilli, pinocytotic vesicles, mitochondria and lysosomes of various electron density. Secretory cells can be divided into four types (A, B, C, D) depending on the cell shape and characteristics of secretory granules. These cells were unicellular glands and had similar characteristics to previously reported on the mantle of the gastropod and bivalves.

• Korean Journal of Weed Science
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• v.13 no.2
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• pp.96-103
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• 1993

The experiments on the ecological characteristics of the suspensible green algae and the algae causing soil-flakes and shier chemical control were conducted in 1992. The unicellular green algae which were dominated by Chlamydomonas sp. largely occurred when phosphorus was applied, but which were reduced by nitrogen application. The filamentous green algae which were dominated by Klebsormidium sp. largely occurred when phosphorus was applied, and which much more increased when nitrogen or potassium was combined with phosphorus. The suspensible green algae which were dominated by Klebsormidium sp. were controlled by 60-70% when simazine 10g ai/10a and propanil 105g ai/10a were applied. The dark blue soil-flakes largely occurred at nitrogen application, and which much more increased when nitrogen was combined with phosphorus. The dark brown soil-flakes largely occurred at phosphorus application, but no more increased even if nitrogen or potassium was combined with phosphorus. The dark blue soil-flakes which were dominated by Oscillatoria sp. much more increased at the temperature conditions of $18^{\circ}C$ compared with $24^{\circ}C$ and $29^{\circ}C$. The applications of bensulfuron/mefenacet/dymron, piperophos/dimethametryn and bensulfuron/dimepiperate controlled 70-90% of the dark blue soil-flakes.

• Journal of Life Science
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• v.27 no.10
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• pp.1152-1160
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• 2017

A unicellular green alga was axenically isolated from a tidal pool on Ulleung-do, Korea. Morphological, molecular, and biochemical analyses revealed that the isolate belonged to Auxenochlorella protothecoides. The current study is the first record of this species in Korea. The microalgal strain was named as A. protothecoides MM0011 and its growth, lipid and pigment compositions, and biomass properties were investigated. The strain is able to thrive in a wide range of temperatures ($5{\sim}35^{\circ}C$) and to withstand up to 1.5 M NaCl. The results of GC/MS analysis showed that the isolate was rich in nutritionally important polyunsaturated fatty acids (PUFAs). Its major fatty acids were linoleic acid (27.6%) and ${\alpha}-linolenic$ acid (39.6%). Thus, this indigenous microalga has potential as an alternative source of ${\omega}3$ and ${\omega}6$ PUFAs, which currently come from fish and plant oils. Also, the HPLC analysis revealed that the value-added antioxidant, lutein, was biosynthesized as the accessory pigments by the microalga. A proximate analysis showed that the volatile matter content was 85.6% and an ultimate analysis indicated that the gross calorific value was $20.3MJ\;kg^{-1}$. Since 40.5% of total nitrogen and 27.9% of total phosphorus were removed from the medium, respectively, it also has potential as a feedstock for biofuel applications which could be coupled to wastewater treatment. In addition, the biomass may also serve as an excellent animal feed because of its high protein content (51.4%). Therefore, A. protothecoides MM0011 shows promise for application in production of microalgae-based biochemicals and as a biomass feedstock.

• Applied Microscopy
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• v.36 no.1
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• pp.35-45
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• 2006

Plants of Vitex negundo are known to develop numerous trichomes throughout their body, where certain trichome types have been believed to be one of the plausible structures for the unique scents. In the current study. structural aspects of the trichomes have been examined in leaves and stems of Vitex negundo using TEM and SEM. Trichome types as well as structural changes that occurred in certain trichomes during secretion have been mainly focused. Three type of glandular trichomes and two types of non-glandular trichomes were developed in the epidermis of young and mature Vitex negundo plants. The glandular trichomes included the peltate type (Type 1), the capitate type (Type 2), and degraded capitate type (Type 3), whereas the non-glandular warty trichomes contained the multicellular (Types 4) and unicellular type (Type 5). Type 1 and 2 consisted of head and stalk cells, but their number and size were different. One secretory cavity was formed from the four head cells in the former, but only two head cells were involved in the latter. The cytoplasmic density in the head cell was quite high and in particular, sER and Golgi bodies were well developed. At initiation of their development, the cuticle layer of the head cells separated from the outer tangential wall to form a secretory cavity. Subsequently the cavity expanded acropetally and a large number of secretory vesicles continuously produced from the head cells until they filled the entire cavity. The cavity contained materials that would be soon discharged into intercellular spaces and/or into the air. The cavity began to decrease the volume by contracting at initial secretion but degrade rapidly within short time. It has been suggested that the mode of secretion in V. negundo is probably the eccrine secretion, since no break or rupture of the cavity has been observed during examination. Contrastingly Type 3 exhibited deterioration of the head cell at early stage. Type 4 was about $110{\sim}190{\mu}m$ long, consisting of $2{\sim}3$ cells, and distributed more in the adaxial epidermis compared to the abaxial surface. However, $20{\sim}30{\mu}m$ long Type 5 was extremely dense in both epidermis. Among several trichome types, Type 1 and 2 probably play an important role in discharging unique aromatic scents in plants of V. negundo.

• Korean Journal of Weed Science
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• v.12 no.2
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• pp.158-165
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• 1992

A survey on nation-wide distribution of fresh-water algae occurring in paddy rice fields was conducted in 1991. The algae which were collected from the whole nation were classified into a total of 54 genera including 14 genera in the blue-green algae. 29 genera in the green algae, 1 genus in the stoneworts. 3 genera in the euglenoids and 7 genera in the diatoms. The green algae and diatoms occurring in plain regions were diverse in terms of the number of genera distributed, whereas there was no regional difference in diversity of the blue-green algae and the euglenoids. Among the green algae, the suspended unicellular algae such as the genera, Chlamydomonas, Pandorina and Gonium, were widespread in plain regions, but the multicellular algae such as the genera, Spirogyra, Oedogonium, Ulothrix and Hydordictyon, were major in mountainous and attitudinal regions. The filamentous green algae such as the genera. Cladophora and Rhizoclonium, were dominant in reclaimed saline fields. The blue-green algae Oscillatoria spp. and the diatoms Navicula spp. were abundant in soil flakes.

• Journal of Life Science
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• v.32 no.3
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• pp.202-209
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• 2022

The green alga Chlamydomonas reinhardtii, a unicellular haploid eukaryote, has long been used by researchers and industries as a cell factory to produce high value-added microalgae substances using genetic modification. Microalga K01, presumed to be Chlamydomonas, was isolated from 12 freshwater samples from the Chungcheong and Jeolla regions to replace C. reinhardtii, an introduced species currently used in most basic and industrial research. The isolated K01 strain was identified as C. reinhardtii through morphological and phylogenetic studies of the 18S rDNA gene sequence (NCBI accession number KC166137). The growth and lipid content of the isolated C. reinhardtii K01 were compared with three wild and four mutant strains in TAP medium, and it was found that the K01 strain could produce 1.74×10⁷ cells/ml by the third day of culture. The growth rate of C. reinhardtii K01 was 1.5 times faster than UTEX2244, which showed the highest number of cells (1.20×10⁷ cells/ml) among the compared strains. The lipid content of the isolated C. reinhardtii K01 (20.67%) was similar to those of the wild strains, although the fatty acid oleate C18:1 was not detected in the isolated strain but was identified in the seven others. The cell density of the isolated strain increased to 0.87 g/l during a six-day culture in BG11 medium, where nitrate (NaNO₃) was introduced as a nitrogen source, while the seven acquired strains showed almost no cell proliferation.