• Korean Journal of Plant Resources
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• v.31 no.4
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• pp.363-371
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• 2018

Tiarella polyphylla D. Don is a native plant distributed only in Ulleung Island in Korea and has been traditionally used for medicinal purposes, although it is also used ornamentally. This study was conducted to determine the requirements for dormancy break and germination and to classify the type of seed dormancy. The experiments were performed with cold stratification (0 or 12 weeks at $5^{\circ}C$), warm stratification (0, 4, 8, or 12 weeks at $23^{\circ}C$, followed by 8 weeks at $5^{\circ}C$, and then incubation at $23^{\circ}C$), and $GA_3$ treatments (0, 10, 100, or 1000 mg/L). The treated seeds were incubated on aseptic media at room chamber ($23^{\circ}C$, a 16h photoperiod of fluorescent lamps with $40{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$). The seeds were dispersed in nature as underdeveloped embryos with no physical barrier to absorb water to prevent water absorption. However, the seeds did not germinate for 30 days after sowing without any pre-treatments. Thus, the seeds had morphological dormancy (MD) and physiological dormancy (PD). The final germination percentage following cold stratification (0 or 12 weeks) was 66.7% and 45.6%, respectively. The cold stratification delayed seed germination by about 3 weeks. In the warm stratification experiment (0, 4, 8, or 12 weeks), the final germination percentage was 21.1%, 27.8%, 41.1%, and 57.8%, respectively, 20 weeks after sowing. The embryos of the T. polyphylla seed grew in relatively warm temperatures ($23^{\circ}C$). $GA_3$ application overcame seed dormancy and promoted germination. Following $GA_3$ treatment (0, 10, 100, or 1000 mg/L), the final germination percentage was 33.3%, 45.0%, 42.5%, and 72.5%, respectively. These results suggest that the T. polyphylla seeds had non-deep simple morphophysiological dormancy (MPD) and $GA_3$ treatment could be used as a substitute for warm stratification for breaking seed dormancy. To our knowledge, this is the first report of seed dormancy characteristics of the genus Tiarella native to Korea.

• Proceedings of the Korean Society of Plant Pathology Conference
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• 2003.10a
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• pp.78.1-78
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• 2003

An osmotin-like protein (CAOSMl) gene was isolated from pepper leaves infected with the avirulent strain Bv5-4a of Xmthomonas campestris pv. vesicatoria. The cDNA encodes a polypeptide of 250 amino acids with a molecular mass of 27, 361 Da. Its amino acid sequence is highly homologous to various osmotin-like proteins from other plant species. The CAOSMl gene expression was organ- and tissue-specifically regulated In pepper plants. The CAOSMl mRNA was intensely localized in the endodermis area of root tissue and in the phloem cells of vascular bundles of red fruit tissue, but not in leaf, stem, and green fruit tissues of healthy pepper plants. Infection by X. c. pv vesintoria, Colletotrichum coccodes, or Phytopkhora capsici iinduced CAOSMl transcription in the leaf or stem tissues. Expression of the CAOSMl gene was somewhat higher in the incompatible than the compatible interactions of pathogens with pepper. The CAOSMl mRNA was prevalently localized in the phloem cells of the vascular bundle of leaf tissues infected by C. coccodes. The CAOSMl gene was activated in leaf tissues by treatment with ethylene, methyl jasmonate, high salinity, cold acclimation and mechanical wounding, but not by abscisic acid (ABA) and drought. These results indicate that the pepper CAOSMl protein functions in response to Pathogens and some abiotic stresses in pepper plants

• Journal of Korean Society of Forest Science
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• v.103 no.3
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• pp.321-338
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• 2014

In the Natural Monument (No. 432) Jeju Sanghyo-dong Cymbidium kanran Habitat (39 ha), flora, vegetation diversity, stand structure, mirco-climate, canopy openness, light environment and soil temperature and moisture were quantified from Oct. 2013 to Feb. 2014. Compare to Seogwipo-si, daily mean temperature ($5.7^{\circ}C$) and moisture (75.8%) in study area were lower at $3.3^{\circ}C$ and 15%, respectively. Mean soil temperature and moisture were $16.5^{\circ}C$ and 37.3%, respectively, and mean litter layer depth (n = 81) was 4.3 cm. Mean canopy openness and light availability at forest floor were 15.5% and $8.5mol{\cdot}m^{-2}{\cdot}day^{-1}$, respectively. Total of 22 species including vascular and bryophyte plants and 6 vegetation group were observed. Castanopsis siebildii was dominant species in study area, and density and basal area were 1,777 stem/ha and $90.3m^2/ha$.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.170-175
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• 2013

Korea is carrying out weed quarantine by plant quarantine regulations including heat-treatment method to prevent the influx of exotic weeds. In order to confirm suitability for current heat-treatment criteria and find field-applicable methods which can completely devitalize quarantine weed seeds, the conditions for heat-treatment with/without 40% relative humidity were studied with 9 species among quarantine weed seeds and one weed species similar to quarantine weed. Dry heat-treatments had been tested under various temperatures and time conditions. All seeds were dead at the conditions of $95^{\circ}C$ for 48 hours, $100^{\circ}C$ for 36 hours, $110^{\circ}C$ for 24 hours, $121^{\circ}C$ for 4 hours and $130^{\circ}C$ for 30 minutes. Heat-treatments at 40% relative humidity resulted in complete seed death at the conditions of $85^{\circ}C$ for 36 hours and $90^{\circ}C$ for 16 hours. The above results show that current heat-treatment criteria are not suitable for several quarantine weeds and these conditions could be applied as a quarantine method to prevent the influx of quarantine weeds along with agricultural imports. More specific conditions for heat tolerant species such as Picris echioides and heat susceptible species such as Cuscuta spp. are necessary and will improve plant quarantine process in devitalizing quarantine weed seeds with different heat tolerances.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.135-139
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• 2001

The study was conducted to investigate quality changes by different shelf temperature after storage at $5^{\circ}C$ for 15 days. Fruits on the shelf at room temperature produced more $C_2H_4$ and $CO_2$ than those at $5^{\circ}C$ by 30% and seven times, respectively. By 10 days on the shelf, flesh firmness was held better at $5^{\circ}C$, while it was softened very rapidly at $13^{\circ}C$ and room temperature. In contrast, at low shelf temperature, contents of soluble solid did not show significant difference except that, in room temperature, it showed tendency to decrease. Sucrose content tended to be higher on the third day of marketing. At room temperature, however, all the sugar contents decreased from 10 days of marketing. Small quantity of ethanol and acetaldehyde were detected on the first day of marketing at $5^{\circ}C$ and $13^{\circ}C$, but they were high at room temperature. Also, these contents increased significantly with prolonging the shelf period and with rising marketing temperature.

• Research in Plant Disease
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• v.12 no.1
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• pp.32-39
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• 2006

This study has been conducted to investigate the responses of various isolates of four Colletotrichum species such as C. gloeosporioides, C acutatum, C. coccodes, and C. dematium isolated from infected tissues of several crops to fungicides such as carbendazim, carbendazim+diethofencarb, four protective fungicides, and three ergosterol biosynthesis-inhibiting (EBI) fungicides. All the isolates of C. acutatum showed $EC_{50}$ values in a range of 0.001-3.040 ${\mu}g/ml$ against carbandazim, a benzimidazole fungicide. As for the response to carbendazim, the isolates of C. gloeosporioides obtained from pepper, apple, and strawberry were clearly divided into two groups, resistant or sensitive isolates. All the resistant isolates showed $EC_{50}$ values above 1000 ${\mu}g/ml$, whereas the sensitive isolates had lower $EC_{50}$ values than 0.550 ${\mu}g/ml$. The isolates of C. gloeosporioides exhibited a negative cross resistance between carbendazim and diethofencarb (a N-phenylcarbamate fungicide), but isolates of C. acutatum did not. Toward carbendazim, C. coccodes and C. dematium isolates showed a similar response to C. acutatum isolates and the sensitive isolates of C. gioeosporioides, respectively. As for response of Protective fungicides, all the isolates of C. acutatum showed a more resistant reaction than all the isolates of C. gloeosporioides. However, there was no difference among 4 species of Colletotrichum against EBI fungicides.

• Korean Journal of Medicinal Crop Science
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• v.24 no.4
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• pp.277-283
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• 2016

Background: The photosynthetic efficiency cool-season, semi-shade ginseng is normal at low morning temperatures, but drops at high afternoon temperatures. Therefore, optimal plant performance would be ensured if it were possible to control daily light transmission rates (LTR). Methods and Results: Plants were grown in a controlled light environment that replicated 11 AM conditions and comparatively analyzed against plant grown under normal conditions. Growth in the controlled light environment resulted in a 2.81 fold increase in photosynthetic efficiency with no change in chlorophyll content, although LTR were high due to low morning temperatures. Increased aerial plant growth was observed in the ginseng plants adapted to the controlled light environment, which in turn influenced root weight. An 81% increase in fresh root weight (33.3 g per plant on average) was observed in 4-year-old ginseng plants grown in controlled light environment compared to the plants grown following conventional practices (18.4 g per plant on average). With regard to the inorganic composition of leaves of 4-year-old ginseng plants grown in controlled light environment, an increased in Fe content was observed, while Mn and Zn content decreased, and total ginsenoside content of roots increased 2.37 fold. Conclusions: Growth of ginseng under a favorable light environment, such as the condition which exist naturally at 11 AM and are suitable for the plant's photosynthetic activity creates the possibility of large scale production, excellent-quality ginseng.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.273-273
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• 2017

Polyploidy has opened a new horizon for selection to sculpt a variety of new gene functions, traits, and lineages. The aim of this study was to investigate the efficacy of the colchicine concentration, temporal changes, and suitable material for inducing effective tetraploid plants of Codonopsis lanceolata. A total of 180 individuals from 16 treatment groups were germinated, and exposed to different concentrations of Colchicine. The plant height of the diploid (18.1 cm) was slightly shorter than that of the tetraploid (13.4 cm). The fresh weight of the main root in the diploid (0.5 g) was 4-fold higher than the tetraploid (2.2 g). The colchicine-treated plant regeneration rate in C. lanceolata was decreased at the elevated concentration of colchicine. A total of 126 individual plants were regenerated in the entire treatment group and tetraploid (2n=4x=32) plants were obtained. In particular, 5 individuals of the tetraploid plant were induced in the 0.05% colchicine for 6h, which is a higher rate (29.4%) than other regenerated plants. As in the seed treatment result, the plant height of the diploid was significantly higher (10.4 cm) than tetraploid. The root length of the tetraploid (10.1 cm) was longer than the diploid, and the root was also thicker. Taken together, the results obtained from the present study may be helpful for the efficient recovery of such polyploid plants through the in vitro application of colchicine, and may improve the productivity and breeding of C. lanceolata.

• The Plant Pathology Journal
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• v.30 no.1
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• pp.68-74
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• 2014

Chrysanthemum stunt viroid (CSVd), a noncoding infectious RNA molecule, causes seriously economic losses of chrysanthemum for 3 or 4 years after its first infection. Monomeric cDNA clones of CSVd isolate SK1 (CSVd-SK1) were constructed in the plasmids pGEM-T easy vector and pUC19 vector. Linear positive-sense transcripts synthesized in vitro from the full-length monomeric cDNA clones of CSVd-SK1 could infect systemically tomato seedlings and chrysanthemum plants, suggesting that the linear CSVd RNA transcribed from the cDNA clones could be replicated as efficiently as circular CSVd in host species. However, direct inoculation of plasmid cDNA clones containing full-length monomeric cDNA of CSVd-SK1 failed to infect tomato and chrysanthemum and linear negative-sense transcripts from the plasmid DNAs were not infectious in the two plant species. The cDNA sequences of progeny viroid in systemically infected tomato and chrysanthemum showed a few substitutions at a specific nucleotide position, but there were no deletions and insertions in the sequences of the CSVd progeny from tomato and chrysanthemum plants.

• Plant Biotechnology Reports
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• v.4 no.4
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• pp.303-309
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• 2010

Endoreduplication is a developmental process that is unique to plants and occurs in all plants. The present study aimed to assess endoreduplication in various explant tissues and regenerated somatic embryos of Doritaenopsis. We further investigated the effects of light quality on endoreduplication and somatic embryo proliferation. To this end, we studied endoreduplication in leaves and root tips from regenerated plantlets and somatic embryos and in developing somatic embryos under 4 types of lighting conditions: red light, red + far-red light, red + blue light, and white light. We found that the degree of endoreduplication varied in different explants, and that the choice of explants used also influenced the ploidy levels of the newly regenerated somatic embryos. The DNA content of the leaf (2C-8C) was less than that of the root tip (2C-16C) and somatic embryo (2C-64C). In terms of light quality, the combination of red and far-red light produced the highest number of somatic embryos, while maintaining a low degree of endoreduplication. The data obtained indicate that this light combination stimulates somatic embryogenesis in Doritaenopsis and may exert some control on endoreduplication during cell division. These findings can be applied to achieve a reduction in somaclonal variations for the purpose of mass proliferation and genetic improvement.