• Weed & Turfgrass Science
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• v.3 no.3
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• pp.232-239
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• 2014

Zoysiagrass seeds had low germination or lack of germination uniformity under natural condition. To improve the final germination percentage of zoysiagrass seeds, we investigated the methods of proper pre-treatment to enhance germination rate of zoysiagrass. Seeds were subjected to the testa scarification and four types of seed priming methods, namely, hydro priming (distilled water), osmotic priming (polyethylene glycol -0.5 MPa, -1.0MPa, -2.0 MPa), halo priming (Potassium nitrate 100 mM, 200 mM, 400 mM), and solid matrix priming (seed : microcel-E : distilled water = 4:1:8) with and without 25% KOH treatment in the testa. The scarification improved the germination rate and reduced the germination time. Osmotic priming (PEG -0.5 MPa) with scarification were significantly increased the seed germination rate and decreased MGT, and $T_{50}$. Seed germination rate obtained by osmotic priming (PEG -0.5MPa) with scarification increased above 60% in comparison with natural condition. Conclusively, scarified and primed zoysiagrass seed germinated more rapidly and uniformly in the study. The present results suggested that PEG priming treatment with KOH treatment prior to sowing could improve germination percentage, and this method makes us establish the early zoysiagrasses in the field.

• Horticultural Science & Technology
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• v.28 no.3
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• pp.522-527
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• 2010

Onion has been reported to contain various organosulfur compounds which have antibiotic and anticarcinogenic properties and flavonoid like quercetin which is a valuable natural source of antioxidants. Carbohydrates in onion constitute about 80% of dry matter, and the major non-structural carbohydrate of onion bulb is fructo-oligosaccharides, well known as fructan, followed by glucose, fructose, and sucrose. The sugar concentration is associated with dormancy and storage life of onion, occurring as decrease in glucose, fructose and fructan, particularly towards the end of storage. Forced air pre-drying for 15-20 days at room temperature is an essential procedure to reduce freezing injury and sprouting, then onion bulbs can be stored at $0^{\circ}C$ for 6 months to control sprouting and decay. Bacterial soft rot caused by $Erwinia$ and $Pseudomonas$ is the main postharvest disease when the bulbs are infected with the bacteria and stored at room temperature. Browning in sliced onion is due to oxidation of phenolic compounds by polyphenol oxidase and it can be inhibited by citric acid treatment, packing with nitrogen gas, and polyethylene film.

• Horticultural Science & Technology
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• v.31 no.5
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• pp.648-651
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• 2013

A new cultivar 'Daewang' strawberry was developed by the National Institute of Horticultural & Herbal Science for forcing culture in 2010. The cultivar 'Daewang' was originated from the cross between 'Maehyang', a high firmness cultivar and 'Wongyo 3111', a high sugar content in 2006. The cultivar shows erect plant type, vigorous growth habit, early flower bud differentiation with 12-15 flowers per cluster from planting on healthy nursery. Fruits of 'Daewang' are conical type having a bright red skin color, and 16-17 g in an average weight. 'Daewang' is suitable for forcing culture as time required for dormancy breaking ranged between 50 and 100 hours. This cultivar has excellent taste for high sugar/acid ratio as sugar content of $11.1^{\circ}Brix$, acidity of 0.39% with abundant texture and can be harvested by late spring because the fruit firmness of 'Daewang' was $18.2g{\cdot}mm^{-2}$ that was about $7.9g{\cdot}mm^{-2}$ higher than $10.3g{\cdot}mm^{-2}$ of 'Akihime' cultivar. But although total yield is not significantly different from 'Akihime' cultivar, its marketable yield is remarkably higher than that of 'Akihime' cultivar. Disease and pest resistance of 'Daewang' have a tendency to sensitive powdery mildew, anthracnose and spotted spider.

• Korean Journal of Plant Resources
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• v.32 no.5
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• pp.615-632
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• 2019

Field surveys were conducted from May 2016 to October and from April to October 2017 in Tributary Region of Middle Stream of the Nakdong River. The survey was carried out at 66 sites including Young-gang 11, Naeseong-cheon 21, Wi-cheon 16, and Gam-cheon 9, Byeongseong-cheon 9. As a result of investigation, 474 taxa in total ; 99 familly, 288 genera, 421 species, 4 subspecies, 39 varieties and 10 forma. Among them, 5 Korean endemic plants, 7 rare plants, 31 taxa were listed as Floristic Target Species in Korea. Naturalized plants was confirmed 73 taxa, their Urbanization Ratio 22.7%, and naturalization ratio 15.4% in the investigated area. The Life form(Dormancy form) review results as follows ; Therophytes 159 taxa, Hemicryptophytes 91 taxa, Hydrophanerophytes 68 taxa, Geophyte 52 taxa, Nanophanerophytes 35 taxa, Megaphanerophytes 32 taxa, Microphanerophytes 25 taxa, Chamaephytes 12 taxa, and Epiphyten 1 taxa.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.424-436
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• 2007

In this paper, it was discussed situations and necessities of conservation management strategy for the woody plants resources in Jeju Island. Out of 320 taxa of the woody plants distributed in Jeju, there were 62 families, 136 genus, 279 species, 28 varieties and 13 forma. Conifers, gymnosperms, were 3 families, 5 genus and 7 species as holding 2.2% of total woody plants. Broad leaves, angiosperms, were 59 families, 131 genus, 272 species, 28 varieties and 13 forma that were 313 taxa. Evergreens were 84 taxa consisting of 31 families, 45 genus, 72 species, 7 varieties and 5 forma that make up 26.8% out of total angiosperms. Deciduous were 229 taxa(73.2%) consisting of 42 families, 93 genus, 200 species, 21 varieties and 8 forma that were 122 trees(38.1%), 177 shrubs(55.1%) and 21 vine plants(6.8%). Life form spectra by dormancy, disseminule, radicoid and growth form were analysed. Thirty eight taxa including 17 families, 21 genus, 14 species and 16 varieties out of 320 taxa growing Jeju were endemic to Korea and 22 taxa of them were endemic to Jeju. The specific plant species among the woody plants in Jeju were 10 taxa in V grade, 24 taxa in IV grade and 53 taxa in III grade. These are correspondence to those of nations as 12% of V grade, 7.6% of IV grade and 17.2% of III grade.

• The Journal of the Petrological Society of Korea
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• v.28 no.2
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• pp.143-156
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• 2019

We carried out the sensitive high resolution ion microprobe zircon U-Pb age dating and whole rock geochemical analysis of granites in the Gudambong and Sainam geosites, Danyang Geopark. The granites crop out in the western and southern parts of Danyang County, and intruded sedimentary successions of the Yeongweol and Taebaek Groups, respectively. The U-Pb isotopic compositions of zircon from the Gudambong and Sainam granite samples yielded the Cretaceous intrusion ages of $90.4{\pm}0.5Ma(t{\sigma})$ and $90.0{\pm}1.5Ma(t{\sigma})$, respectively. The major and trace elements compositions of the samples showed an affinity of typical A-type granite, indicating their petrogenesis during the late stage of the Bulguksa orogeny or a tectonic dormancy. The geochronologic and geochemical results are identical to those of granites previously reported from the Cretaceous Muamsa and Wolaksan suites.

• Journal of Ginseng Research
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• v.43 no.1
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• pp.38-48
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• 2019

Background: Interspecific ginseng hybrid, Panax ginseng ${\times}$ Panax quenquifolius (Pgq) has vigorous growth and produces larger roots than its parents. However, F1 progenies are complete male sterile. Plant tissue culture technology can circumvent the issue and propagate the hybrid. Methods: Murashige and Skoog (MS) medium with different concentrations (0, 2, 4, and 6 mg/L) of 2,4-dichlorophenoxyacetic acid (2,4-D) was used for callus induction and somatic embryogenesis (SE). The embryos, after culturing on $GA_3$ supplemented medium, were transferred to hormone free 1/2 Schenk and Hildebrandt (SH) medium. The developed taproots with dormant buds were treated with $GA_3$ to break the bud dormancy, and transferred to soil. Hybrid Pgq plants were verified by random amplified polymorphic DNA (RAPD) and inter simple sequence repeat (ISSR) analyses and by LC-IT-TOF-MS. Results: We conducted a comparative study of somatic embryogenesis (SE) in Pgq and its parents, and attempted to establish the soil transfer of in vitro propagated Pgq tap roots. The Pgq explants showed higher rate of embryogenesis (~56% at 2 mg/L 2,4-D concentration) as well as higher number of embryos per explants (~7 at the same 2,4-D concentration) compared to its either parents. The germinated embryos, after culturing on $GA_3$ supplemented medium, were transferred to hormone free 1/2 SH medium to support the continued growth and kept until nutrient depletion induced senescence (NuDIS) of leaf defoliation occurred (4 months). By that time, thickened tap roots with well-developed lateral roots and dormant buds were obtained. All Pgq tap roots pretreated with 20 mg/L $GA_3$ for at least a week produced new shoots after soil transfer. We selected the discriminatory RAPD and ISSR markers to find the interspecific ginseng hybrid among its parents. The $F_1$ hybrid (Pgq) contained species specific 2 ginsenosides (ginsenoside Rf in P. ginseng and pseudoginsenosides $F_{11}$ in P. quinquefolius), and higher amount of other ginsenosides than its parents. Conclusion: Micropropagation of interspecific hybrid ginseng can give an opportunity for continuous production of plants.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.40 no.3
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• pp.269-277
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• 1995

This experiment was conducted to study on forage utility of native grasses in polderland for salt tolerance plant selection and good feed with collection and evaluation. As the result of investgate, it was carried out feed evaluation, germination physiology and early growth at the different salt content of Puccinellia coreesis Honda and P. nipponica Ohwi from May 1993 to June 1994. Germination physiology of the grasses was light and low temperature favored optimum germination temperature was 1$0^{\circ}C$, germination period was 30 days. Dormancy awakening was needed wet and high temperature condition with 1~3 days storage. Germination rate increased 18.0% of P. coreensis and 39.0% of P. nipponica than those of non treatments. Early growth condition of different salt content was good also at in 1.00% and 0.50% levels of P. coreensis and P. nipponica. Crude protein content was 8.4% at P. coreensis, 7.1% at P. nipponica and 10.3% of Italian ryegrass, and NFE content was arrangement in order of P. coreensis, Italian ryegrass and P. nipponica. TDN content was not different between P. coreensis, P. nipponica and Italian ryegrass. Also P. coreensis and P. nipponica have a good taste for cattle as same as other crops.

• International Journal of Industrial Entomology and Biomaterials
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• v.46 no.1
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• pp.16-23
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• 2023

The silkworm's dormancy and embryonic development are accomplished through the interaction of various genes. Analysis of the expression of several interacting genes can predict the embryonic stage of silkworms. In this study, we analyzed the changes in the expression level of genes at each stage during the embryonic development of dormant silkworm eggs and selected genes that can predict the hatching time. Jam123 and Jam124 silkworms were collected after egg laying, and the silkworm eggs were preserved using a double refrigeration method and expression analysis was performed for 23 genes during embryogenesis. There were 5 genes showing significant changes during embryogenesis: UDP-glucuronosyltransferases (BmUGTs), heat shock protein hsp20.8 (BmHsp20.8), Cytochromes b5-like proteins (BmCytb5), Krüppel homolog 1 (BmKr-h1), and cuticular protein RR-1 motif 41 (BmCpr41). As a result of quantitative comparison of the expression levels of these 5 genes through real-time PCR, the BmUGTs gene showed a difference between Jam123 and Jam124, making it difficult to see it as an indicator for predicting hatching time. However, the BmHsp20.8 gene had a common expression decreased at the imminent hatching stage. In addition, it was confirmed that the expression level of the BmCytb5 gene decreased to the lowest level at the time of imminent hatching, and the expression of the BmKr-h gene was made only at the time of imminent hatching. The expression of the last BmCpr41 gene can be confirmed only at the time of imminent hatching, and it was confirmed that it shows a rapid increase right before hatching. Taken together, these results suggest that expression analysis of BmHsp20.8, BmCytb5, BmKr-h1, and BmCpr41 genes can determine the stage of embryogenesis, predict hatching time, which facilitate better management of silkworm eggs.

• Korean Journal of Environmental Biology
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• v.40 no.3
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• pp.239-246
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• 2022

Lactuca scariola L. is one of ecosystem-disturbance plants that grow everywhere such as roadsides, grasslands, railroads, banks, and fields. L. scariola usually occurs in autumn. It overwinters in rosette form. It flowers and produces seeds in early summer of the next year. Seeds of L. scariola can germinate immediately without dormancy when the temperature is over 20℃. Due to endogenous bacteria in seeds of L. scariola, it has a strong drought tolerance. Thus, it can grow well on roadsides. L. scariola should be controlled as it can result in 60-80% of soybean yield loss at densities above 50 plants m^-2. It is advisable to remove L. scariola as it competes with native plants by acting as a pioneer to other ecosystem-disturbance plants. Among various control methods, chemical control is the most effective method that is widely used. Soil treatment with herbicides such as oxyfluorfen EC and pendimethalin EC can inhibit the development of L. scariola. Foliar treatment herbicides glyphosate and glufosinateammonium are widely used. L. scariola is resistant to 2,4-D, dicamba, and MCPA among foliar treatment herbicides. Thus, it is recommended to apply herbicides with different modes of action.