• Korean Journal of Medicinal Crop Science
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• v.9 no.2
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• pp.124-129
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• 2001

Crotalaria sessiflora is one of a few medicinal herbs among the legumes used as antitumor herb medicine but has lower seed germination and afterward seedling emergence. This study was carried out to elucidate the effects of cold stratification as presown treatment as well as $GA_3$, $KNO_3$ and acetone on its seed germination and seedling emergence. Cold stratification, $GA_3$, $KNO_3$ and acetone treatments were performed with different concentrations and period levels. Cold treatment was done under 14 hour red light illumination a day or darkness and the two others under darkness. On the basis of the best germination rate of each treatment, $GA_3$ and cold stratification treatments showed the highest germination rates at 0.1 mM but 12 hours and 2 week periods under darkness, respectively. $KNO_3$ and acetone treatments came out at 400 mM and 200 mM lasted for, respectively. The best germination rates from $KNO_3$ and acetone were comparatively higher than those from the former $GA_3$ and cold treatments. In evaluation of seedling emergence using the last two treatments, $KNO_3$ treated seeds were better performed than acetone treated seeds showed somewhat higher germination rate, implying that presown seed treatments must be evaluated by the combination with indoor and field tests.

• Journal of Crop Science and Biotechnology
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• v.11 no.3
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• pp.199-204
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• 2008

Seed dormancy behavior of weed seeds is a critical determinant of their survival rates in a given cropping system as it helps the weeds to evade herbicides and other weeding practices. We investigated the effects of red light, alternating temperature, stratification duration and different doses of nitrogen containing compounds alone or in combination with red light on breaking seed dormancy of Chenopodium album L. The application of red light(80 ${\mu}mols^{-1}m^{-2}$) significantly increased seed germination of C. album in all treatments. Germination rates of 12 h incubated seeds were highest under 20 min of red light irradiation than 1 min, 5 min and 10 min treated seeds. Germination rate was significantly higher at alternating temperatures of $25^{\circ}C\;and\;5^{\circ}C$ for 12 h each with an irradiation of red light(80 ${\mu}mols^{-1}m^{-2}$) for 10 min than other treatments. Stratification period of 15 days significantly stimulated germination percentage of seeds incubated in dark, although 5 days of stratification along with red light application for 10 minutes exhibit similar effects on seeds. Seed germination was also enhanced by nitrogen containing compounds like $NaNO_2,\;KNO_3,\;NH_4Cl\;and\;NH_4NO_3$. We observed that seed germination increased significantly with 25 mM $KNO_3$ and 10 mM $NH_4NO_3$ in dark condition, while $NaNO_2$ and $NH_4Cl$ enhanced seed germination under red light irradiation. It was concluded that red light alone or synergized with alternating temperatures, stratification and nitrogen compounds, especially nitrite and ammonium enhanced seed germination of C. album. Thus, the red light can play a vital role in present and future weed management strategies.

• Journal of the Korean Institute of Landscape Architecture
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• v.26 no.1
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• pp.28-35
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• 1998

Six soil compositions with three seeding rates were evaluated for influence on germination, coverage, height and sod development of Phragmites japonica. 1. Germination was high on peat, vermiculite and bark as compared with on peatmoss and sandy loam. 2. Covering rate was high within 2 months when seeded at 9g/$m^2$, but became same within 3 months afterwards when seeded at 3,6 and 9g/$m^2$, respectively. 3. Sod was highly developed on peat and bark treatments whereas Sandy loam, peatmoss and vermiculite treatments didn't develop sod. 4. Sod grown on bark weighed light and, therefore, was suggested best from a dealing cost point of view. 5. Cutting at 10 cm height didn't influence on sod development regardless of soil compositions.

• Journal of Plant Biology
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• v.22 no.4
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• pp.95-100
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• 1979

As a part of the studies on the regulatory mechanism of gene expression by $GA_{3}$ , the effects of $GA_{3}$ on the protein biosynthesis and phosphorylation in maize seedlings were investigated. 1. The optimum concentration of $GA_{3}$ for the stimulation of the protein biosynthesis was 0.3mM. 2. The protein biosynthesis was remarkably increase by $GA_{3}$ during the germination. The reason for the decrease in the protein biosynthesis by 48hrs. after germination seems to be a staggered gene expression, and/or increases in protease and RNase activities. 3. The ratio of the amount of the newly synthesized protein in germinating seeds treated with $GA_{3}$ to the amount of proteins secreted into the endosperm was similar to that ratio in control. According to this result, it seems that $GA_{3}$ stimulates only the expression of certain definite genes. 4. By the treatment with $GA_{3}$, the rates of biosynthesis and phosphorylation of proteins were increased up to about 1.5 times during germination and 6 times by 72hrs. after germination, respectively. The ratio of the total soluble proteins to the phosphorpoteins considerably increased in the early germination stage (24hrs.) but decreased after 24hrs. According to the above mentioned results, the stimulation of the phosphorylation of proteins of $GA_{3}$ seems to be attributed to the increases in the activities of protein kinases.

• Korean Journal of Plant Resources
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• v.8 no.1
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• pp.41-46
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• 1995

This experiment was carried out to investigate the effects of temperature, light quality and gibberellic acid on the seed germination of Rhododendron weyrichii Max. Optimum temperature for germination was $20^{\circ}C$ at constant temperature, but the final germination rate at $15^{\circ}C$ was about the same with the rates were attained by alternating temperature under higher temperature such as $25^{\circ}C$ or $30^{\circ}C$. The germination rate was increased by yellow and red light treatments at $20^{\circ}C$, but green light treatment strongly inhibited seed germination at $25^{\circ}C$. Gibberellic acid substitutes light requirement for germination of R. weyrichii seeds.

• Weed & Turfgrass Science
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• v.2 no.2
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• pp.152-158
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• 2013

Dandelion (Taraxacum officinale) is a member of family Asteraceae that grows all over the Korea. Recently, dandelion was cultivated for medicinal crops because of its positive medicinal effects. However, dandelion is considered as a troublesome weed in grass lawns of golf course and orchards. This study was conducted to investigate the effect of plant growth regulators [gibberellins ($GA_3$); kinetin; salicylic acid (SA); ethephon)] with different concentration on seed germination control of dandelion. Seed germination rates were increased in all concentration of $GA_3$ and kinetin treatment compared to control. In the 0.5 mM of ethephon application, seed germination rate was more increased than that of control while seed germination rate was reduced in 1.0 and 1.5 mM of ethephon treatments. Seed germination rate was significantly decreased with different SA dilutions compared to control. The germination rate was more reduced when SA was applied in combination with $GA_3$ than only SA treatments.

• The Korean Journal of Ecology
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• v.16 no.2
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• pp.135-149
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• 1993

In order to study and ecotypic variation of Phragmites communis Trin., we investigated germination rates, velocities, and protein band patte군 of seeds of three population of salt marsh, estuary and fresh water areas of Muan Peninsular in southwestern coast of Korea from March, 1990 to October, 1992. The highest germination rates of seeds were observed at $25^{\circ}C$; those of population of the estuary and fresh water are were 100% and that of the salt marsh was 95%. Similar germination rates were observed from the populations of estuary and fresh water areas at $30^{\circ}C$ and $20^{\circ}C$, but they decreased at $15^{\circ}C$. The onset of germination of seeds of three population was earlier $^{\circ}C$, but they decreased at $15^{\circ}C$. The onset of germination of seeds of th three populations was earlier at both $25^{\circ}C$, which was higher than those of any other areas, while that of fresh water areas was the lowest. were different; those of salt marsh and estuary decreased to 30% and 2.5%, respectively, at 3.0% of salt content, but seeds of the fresh water area did not germinate at all at the same salt content. The onset of germination was delayed in the order of the salt marsh, esturay and fresh water areas as salt content of culture solution increased. Germination of seeds from the population of salt marsh was found to begin earliest. The highest germination velocity of three populations was observed in the culture containing no salt. The germination velocity constant decreased as salt content of culture solution increased from 0.5% to 3.0%: those of the populations of the salt marsh, estuary, and fresh water areas were 9.50, 0.75 and 0.00, respectively, at the salt concentration of 3.0%. Soluble protein patterns of seedings from the three populations were analyzed by SDS-PAGE method. The results showed that protein patterns of the three populations were distinctly different qualitatively and quantitatively. The present study suggests that populations of Phragmites communis Trin. in the coast of Korea had taken ecotypic variations of habitats, i.e., fresh water, estuary, and salt marsh types, according to the salt content.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.58 no.4
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• pp.416-423
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• 2013

Germination is controlled by internal factors of seeds and external factors such as water, temperature and light. We investigated the relationship between germination characteristics of four waxy rice cultivars and patterns of water uptake, antioxidant enzymes and free soluble sugars during early imbibition. Seed viabilities by tetrazolium test of four different rice cultivars were higher than 95% and germination rates of the hulled rice seeds were on 95% average. However, germination rate of intact rice among four cultivars showed a big difference depending on temperature. Water uptake of hulled and intact rice seeds during imbibition reached a stationary phase at around 30% moisture content. Although rates of water uptake were faster in hulled rice and high temperature than intact rice and low temperature condition, difference of those among cultivars was greater under low temperature than high temperature. The time required for rice seeds to uptake 30% water was negatively correlated with percentage of germination, germination energy, germination speed and mean germination time. Guaiacol peroxidase activity at 24h of imbibition was correlated with germination energy and germination speed but not percentage of germination. Catalase activity, soluble protein and maltose concentration at 24h of imbibition were not correlated with characteristics of germination. These results suggest that a time required for rice seeds to uptake 30% of water significantly correlated with germination and guaiacol peroxidase activity during early imbibition plays an important role in initiation of germination.

• Korean Journal of Pharmacognosy
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• v.18 no.3
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• pp.196-201
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• 1987

A study was carried out to investigate the possibility of acclimation of Coptis japonica Makino in Korea. Coptis japonica could be grown within 4 years as a medicinal crude drug if it is cultivated in the area of mountain facing north(300m above sea level) with 70% light interception and appropriate soil texture. It is to be noted that the propagation of the plant is more important than the yield of berberine because the berberine contents do not change in different conditions. The results were as follows; 1. The germination rates of the seeds by covering with the pine tree leaves were the highest and averaged 63%. 2. The germination rates of dry seeds were not affected in spite of low temperature and $GA_3$ treatment. 3. The germination rates of the seeds stored in moistured sand were averaged 85%, but in dry state, they were not germinated. 4. The number of leaves and fresh weight of Coptis japonica from the area of mountain facing north were increased significantly. 5. The growth and fresh weight of Coptis japonica were reduced in clay. 6. The best growth was obtained under 70% light interception. It is possible to intercrop between evergreen trees. 7. The foliage dressing did not affect the growth. 8. The number of leaves and fresh weight were increased from the 3rd year, and the average weight of rhizomes was 5.7g in 4th year. 9. The berberine contents of the rhizomes of Coptis japonica under various treatment conditions ranged from 9 to 10%. Coptidis Rhizoma from this study and from Korean market showed much higher berberine contents than those from Japanese market.

• Journal of Biosystems Engineering
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• v.32 no.1 s.120
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• pp.13-19
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• 2007

Storage rough rice in low temperature using the winter cold air avoids rough rice temperature increase which happens from early May, and this is possible by installing a cooling system in the top of a bin, the room between top rice level and bin ceiling. The research objective is to establish low temperature rough rice storage technique, furnishing winter cold air to rough rice, by investigating the cooling system potential of maintaining low rough rice temperature and by analyzing rough rice storage characteristics over a storage period. The rough rice storage characteristics were evaluated from January to August 2003, using a storage and dry bin of 400-ton capacity. Results of this research are as follows: Cooling bin using the cooling system in the top of the bin maintained the rice temperature less than 15$^{\circ}C$ in entire portions in August. Moisture contents and germination rates of rough rice were decreased over the storage period, on the other hand, the rough rice stored in the ambient temperature bin had relatively lower moisture contents and germination rates to compare with the bin using winter cold air. Crack ratio and acid value of brown rice in the ambient temperature bin storage had increased more than the cooling bin storage. The result indicates that the storage bin using winter cold air and the cooling system maintains moisture content and germination of rice, minimizes cracked kernel and acid value, and preserves rice quality as well.