• Journal of Plant Biology
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• v.37 no.4
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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.

• ALGAE
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• v.18 no.4
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• pp.333-339
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• 2003

To establish a cultivation method of Petalonia fascia, seeds and seedlings cultures and growth tests were performed at the Daeri aquafarm in Haeui, Shinan, Jeollanamdo, Korea. Gametes were easily released from the mature plurilocular sporangia. They developed to crustose discoidal stolons and grew to filamentous and discoidal stolons. The indoor seeding was performed by using the 100-150 ${\mu}m$long fragments of stolons on Porphyra nets and the erect thalli developed from the cuttings when the seawater temperatures were 10-15$^{\circ}C$. In the experimental cultivation in the sea, 1-2mm long plantlets were found after 15 days of cultivation; after two months thalli grew to their maximal size of 215-355 mm long blades; after three months the length of thalli began to decrease due to distal disintegration and the plant color changed to yellow and epiphytic diatoms were attached on the thalli, which deteriorated the quality of products. The cultivation of P. fascia by the regeneration of filamentous-discoidal complexes was carried out successfully for the first time in Korea.

• 한국생태학회:학술대회논문집
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• 1999.05a
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• pp.97.2-97.2
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• 1999

• ALGAE
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• v.20 no.2
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• pp.141-150
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• 2005

To make a preliminary identification of the gracilarioid plant attached to cultivation ropes of Undaria pinnatifida and establish a method of cultivating this plant, the first taxonomic and cultivation studies on this species in Korea were conducted. This gracilarioid plant was identified from its morphological and anatomical features, as Gracilaria chorda. Growth tests using the 10, 20, and 30 cm cuttings of axes of G. chorda were performed twice, from May 3 to August 21, 2002 and from December 15, 2002 to April 3, 2003 in Ihoijin aquafarm, Hoijin, Jangheung, Jeollanamdo, Korea. In the first growing test, the thallus length of the 10, 20, and 30 cm cuttings increased twelve-fold, ten-fold, and seven-fold; the wet weight increased 81-fold, 60-fold, and 41-fold; the numbers of more than 10 cm-long branches increased 3.8-fold, 5.2-fold, and 6.1-fold, respectively. In the second growth test, the thallus length of the 10, 20, and 30 cm cuttings increased seven-fold, 5.5-fold, and four-fold; the wet weight increased 81-fold, 53-fold and 36-fold; the number of branches increased 3.8-fold, 7.3-fold, and 6.6-fold, respectively. The cultivation of G. chorda by vegetative regeneration using cuttings of thallus axes was successful for the first time in Korea.

• 한국생태학회:학술대회논문집
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• 2002.08a
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• pp.133-139
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• 2002

Regeneration process of the Korean beech (Fagus multinervis Nakai) forest was studied in relation to the distributional pattern and age structure. In this study, it was clarified that the Korean beech forest is regenerated in both way: seedlings(sexual reproduction) and sprouts(vegetative reproduction) formations. In the large gaps, seedling may be established, resulting in clusters of even-aged individuals. But in the small-sized gaps, there may filed by the extention of surrounding trees and/or by the young trunks, which have sprouted from the base of stumps. As most gaps in the F. multinervis forest were derived from falling of a single stem, regeneration by sprouts seems to be more common than that by the seedlings.

• The Korean Journal of Ecology
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• v.25 no.4
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• pp.267-273
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• 2002

Regeneration process of the Korean beech (Fagus multinervis Nakai) forest was studied in relation to the distributional pattern and age structure. In this study, it was clarified that the Korean beech forest is regenerated in both way: seedlings(sexual reproduction) and sprouts(vegetative reproduction) formations. In the large gaps, seedling may be established, resulting in clusters of even-aged individuals. But in the small-sized gaps, there may filled by the extention of surrounding trees and/or by the young trunks, which have sprouted from the base of stumps. As most gaps in the F. multinervis forest were derived from falling of a single stem, regeneration by sprouts seems to be more common than that by the seedlings.

• Proceedings of the Korean Society of Plant Biotechnology Conference
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• 2005.04a
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• pp.6-9
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• 2005

Plant biotechnology involving genetic modification has been rather controversial. However, the major issues related to safety are being addressed by continued improvements in technology. Some of the related facts will be highlighted to set the tone for a scientific discussion on the possibilities of using the technology for crop improvement. Our main research interest is to understand the molecular regulation of shoot bud regeneration in plant tissue culture, which is essential for crop improvement by biotechnology. We have isolated and characterized some genes that are associated with adventitious shoot regeneration. These include a MADS-box cDNA (PkMADS1) from paulownia kawakamii, which regulates vegetative shoot development and in vitro shoot regeneration from leaf explants. Another gene we have characterized from petunia codesfor a cytokinin binding protein (PETCBP). Preliminary functional analysis of this gene indicated that this also affects adventitious shoot bud initiation. Also, the antisense suppression of this gene in petunia causedexcessive branching. Results from our work and selected other publications will be used to highlight the possibilities of manipulation of such genes to improve crop species.

• Journal of Korean Society of Forest Science
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• v.84 no.3
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• pp.394-405
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• 1995

Certain ericaceous understory plants of temperate forests proliferate following forest clearcutting and fire. Rapid vegetative growth of these plants may affect conifer regeneration due to their strong competitive abilities and allelopathic properties. Planted conifers in these shrub-dominated habitats experience "growth check" which may result in a loss of productivity or in extreme cases total failure of forest regeneration. This growth check phenomenon is exemplified in Calluna Sitca spruce Scots pine ecosystems of western Europe, Kalmia black spruce ecosystem of eastern Canada and Gaultheria-cedar/hemlock ecosystem of the Pacific Northwest of the United States. Dynamics of Kalmia black spruce ecosystem following disturbance was used to explain the mechanism of conifer growth inhibition and their regeneration failure. It is argued that in addition to competition for nutrients, Kalmia allelopathy plays a major role in growth inhibition of black spruce. This conclusion is supported by the results of various field, laboratory and greenhouse experiments. Eight phenolic compounds were isolated and identified from the leaves of Kalmia angustifolia, four of which are known to be highly phyotoxic to black spruce. Methods of overcoming the allelopathic effects of Kalmia in order to enhance black spruce regeneration in Kalmia-dominated sites are discussed.

• Korean Journal of Plant Tissue Culture
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• v.21 no.5
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• pp.293-297
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• 1994

In order to induce immature pollen derived plants, anthers of Ranunculus japonicus Thunb. were cultured on Murashige and Skoog's medium supplemented with various combinations of auxins and cytokinins. The combinations of NAA and BA were more effective than those of 2,4-D and kinetin in the formation of calli and embryos. Up to 5t5% of the anthers cultured on medium containing 0.5 mg/L NAA and 1.0 mg/L BA gave rise to plantlets. The most suitable stage for anther culture in the induction of calli and/or embryos from immature pollens was at the uninucleate and early binucleate stage (3 days before anthesis). Immature pollens developed into embryos by repeated division of the vegetative nucleate after 60days of culture.

• Korean Journal of Fisheries and Aquatic Sciences
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• v.54 no.3
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• pp.311-317
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• 2021

Growth differences in Caulerpa okamurae thallus parts and the effects of apex removal on growth were examined. Erect fronds, stolons, and erect fronds with stolons (erect+stolon) were grown for 14 days, whereas erect fronds without and with apex removal (-A and +A fronds, respectively), were grown for 25 days. The relative growth rates (RGR) of C. okamurae thallus parts ranged from 1.91% to 4.93% day^-1 with maximal and minimal RGR for the stolon and erect+stolon treatments, respectively. Over the 25 days in culture, the -A fronds showed a higher RGR (2.48% day^-1) than the +A fronds (1.96% day^-1). More new erect fronds and stolons were produced by -A fronds than those by +A fronds. In addition, basal cutting of erect C. okamurae fronds resulted in a greater plant length increase than that obtained from top cutting. These findings indicate that vegetative growth is common in C. okamurae, which has excellent wound healing ability, and cutting damage to erect fronds may stimulate enhanced vegetative growth. Thus, we suggest that stolons and erect fronds of C. okamurae could be used as seeding materials for large scale cultivation. Furthermore, this edible species could be a potential seaweed resource for rapid skin regeneration cosmetics.