• Korean Journal of Medicinal Crop Science
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• v.24 no.3
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• pp.177-182
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• 2016

Background: Many Taraxacum spp. plants are widely used in medicine, but some of them have propagation problems, such as strong dormancy and poor germination rates. This study investigated the effects of temperature, gibberellic acid ($GA_3$), and potassium nitrate ($KNO_3$) on seed germination in Taraxacum ohwianum. Methods and Results: The seeds (NIBRGR0000135524) were exalbuminous, and their length and width were $4.54{\pm}0.032mm$ and $0.97{\pm}0.029mm$, respectively. Various germination temperatures were tested (15, 20, 25, and $30^{\circ}C$), the optimum temperature for germination was found to be $20^{\circ}C$ (31.3%). High temperature ($30^{\circ}C$) resulted in non-typical seedlings (thickened and crumpled cotyledons, with a restricted root system). To increase the germination capacity, $GA_3$ (200, 500, and $1,000mg/{\ell}$) or $KNO_3$ (20, 50, 100, 200, and $500mg/{\ell}$) solutions were used as pre-soaking solutions instead of water. The $GA_3$ treatments increased the germination percentage and rate, but germination percentage was higher with the $KNO_3$ treatments. Under the $50-200mg/{\ell}\;KNO_3$ treatments, the germination percentage exceeded 80% after 12 days, and $50mg/{\ell}\;KNO_3$ was notably effective (91.2% after 15 days). Conclusions: T. ohwianum seeds showed improved germination at low temperatures. The best method for germination was presoaking in $50mg/{\ell}\;KNO_3$ for 24 h, in the dark at $4^{\circ}C$, and then incubating the germinated seed at $20^{\circ}C$ for 15 days.

• Korean Journal of Agricultural Science
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• v.11 no.1
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• pp.85-93
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• 1984

This research was carried out to study the seed dormancy of radishes which were used for summer vegetation. The differences of dormancy of cultivars, maternal effects, the effect of full day length to mother plants, and the effects of chemical treatments for breaking the seed dormancy were considered for this study. These results sere summarized as follows; 1. The germination percentage of 7 cultlvars sown just after harvest were as follows;SP70-:0, PS11-:37.5, GJ75-:75.5, JD127-:77.5, YH85-:81.0, M55-:96.5, and JC73-:98.0%. 2. The dormany of $F_1$ seed of radish was severe when SP70-was used for mother plant. 3. Germination behavior was different by the maturity of plants grown for seed production. The dormancy of seed harvested from immature field-grown plants sown Nov. 10 was deeper than mature plants sown Mar. 22. 4. The germination ratio of tire seed of SP70-radish was increased by treatment of full day length to tire mother plant during full period of growing or since first flowering stage, while that was 0% by treatment since yellow ripening stage. 5. GA 200 ppm+thiourea 0.2% treatment was most effective for breaking of radish seed dormancy.

• Korean Journal of Plant Resources
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• v.20 no.5
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• pp.481-489
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• 2007

Present experiments are conducted to study the seed viability and optimum germination temperature of Polygonatum odoratum var. pluriflorum that is known to have low germination ability and long germination duration. To enhance germination rate, various growth regulators and inorganic salts were employed. Low germination rate was obtained with 4 year old seeds, but not with $1{\sim}2$ year old seeds. The seeds germinated very well under $22{\sim}25^{\circ}C$ and germinated speed was rapid. Especially, $1{\sim}2$ year old seeds germinated at $25^{\circ}C$ showed $70{\sim}71.2%$ germination rate. Priming treatments using $GA_3$, IAA, NAA, kinetin, $KNO_3$, $KH_2PO_4$, $Ca(NO_3)_2$ were effective compared to control except BA. 1 year old seeds treated with $GA_3$ 0.5 mM and IAA 1 mM showed 96% and 93% germination rate, respectively.

• Korean Journal of Plant Resources
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• v.29 no.3
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• pp.339-346
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• 2016

This study was carried out to develop an effective seed propagation method for Thalictrum rochebrunianum var. grandisepalum (H. Lev.) Nakai by analyzing seed dormancy types and germination characteristics. Seeds were collected between September to October at Gangwon province, and well-selected seeds were used while being dry-stored at 4±1℃. The seed size ranged 4.52 × 1.58 ㎜ and the weight of thousand seeds were 1,603.5 ± 0.02 ㎎. The moisture content was 7.2%. Seeds were achene type, and morphology characters showed an elliptical shape and rough texture, and light brown in color. Moist-chilling treatment was conducted for dormancy breaking because the seeds had an undeveloped embryo of liner type. The embryo had developed during a moist-chilling period, constantly, and fully developed in 10 weeks. Consequently, it seemed to be non-deep complex or intermediate complex type of morphophysiological dormancy, and embryo dormancy was broken by wet-chilling for 10 weeks. After 10 weeks of wet-chilling treatment, seed germination began. Germination percentage was higher in dark condition raher than light condition and recorded the maximum at 25℃ in the dark (16.3%). A pre-soaking treatment with a combined plant growth hormones promoted germination and shortened T₅₀. Specifically, seed germination of 84.5% was achieved by pre-soaking of seeds with a combined solution of 500 ㎎/L GA₃ and 10 ㎎/L kinetin for 24 h after a wet-chilling treatment for 10 weeks. Thus the effect of plant growth hormones coupled with chilling temperature on seed breaking dormancy provide asubsequent growth of seedlings for successful plantation.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.29 no.1
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• pp.39-45
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• 1984

The present researches were carried out to investigate the effects of gibberellic acid on the appearance of isozyme patterns of esterase, phosphatase, amylase and peroxidase, also to investigate if there were any differences of the isozyme patterns among root, shoot and seeds of rice plants. It was noticed that the isozyme patterns of the above tested enzymes were differ among the organs, root, shoot and seed. The GA treated plants showed difference of esterase patterns in root from Akibare and the difference in shoot and root from Yushin, phosphatase patterns in root from Akibare. However, the GA did not affect isozyme patterns of amylase or peroxidase. The seed should be the suitable organ to study isozyme patterns for genetics or variety characterization of rice plant.

• Current Research on Agriculture and Life Sciences
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• v.7
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• pp.41-46
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• 1989

The seeds of Malus sieboldii were collected in late fall of 1988 and stored in cold stratification condition for 15 weeks. Growth regulators such as $GA_3$, BA and ABA were treated to the seed to know germination capacity and seedling growth. The results were as follows. 1) Higher germination was achieved in $GA_3$ and BA plots, But ABA treatment showed lower germination percentage and physiological dwarf and also induced to the secondary dormancy condition in partly. 2) Average length of time for germination was delayed over 2 days in ABA plot when comparing with the other plots. 3) Average length of plumule and radicle also was inhibited by ABA treatment. This means lower seedling vigor. 4) Fresh and dry weight of the seeding were higher in BA plot while ABA plot was lower and undesirable seedling was produced. From above mentioned results, it is believed that ABA treatment to the seed induced the secondary dormancy and physiological dwarf pattern. Therefore, utilization of BA can be produced the normal seedling, the authors believed.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.34 no.4
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• pp.325-330
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• 1989

This study was undertaken to assess the effects of seed treatment and soil moisture content on mesocotyl elongation in rice seedlings. The effect of the high temperature pre-treatment on the mesocotyl elongation was 7 times as great as the control (non treatment). The mesocotyl lengths were of maximum value at the 8％ soil moisture, but of minimum value at the 16％ soil moisture plot, showing decreasing trend of mesocotyl length as soil moisture increases. The mesocotyl elongations were much greater at the ABA treated plot than at the GA$^3$, IAA and Kinetin plots. The relationship between the mesocotyl and excised root elongations was not evident, but the weight of excised roots became heavier with longer mesocotyl length.

• Korean Journal of Medicinal Crop Science
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• v.22 no.6
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• pp.423-428
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• 2014

This study was performed to identify optimal harvesting time of ginseng seeds and to examine the effect of $GA_3$ treatment for improvement of seed stratification rate. Ginseng seeds harvested from Land race, Chunpoong and Yunpoong cultivar in July 20 were tested for stratification rate. It was shown that stratification rates of land race, Yunpoong and Chunpoong cultivar were 94.1%, 93.1%, and 82.6%, respectively. Seeds of Chunpoong cultivar harvested 10-15 days later showed a comparable stratification rate to that of Land race, indicating that late harvest of Chunpoong seeds is beneficial for the increase of stratification rate. The higher stratification rate was found in mature seeds (92.3%) than immature seeds (37.8%), both of which were harvested in July 20. Stratification rate of mature seeds harvested in July 15 was 87.5%, demonstrating optimal harvesting time of ginseng seeds with higher stratification rate is after mid-July. An exponential growth of endosperms of ginseng seeds was observed from early June to mid-June and then slow growth was observed. There was no obvious growth of embryos from fertilization to mid-August. After the this time, embryos quickly grew until late October. Thus, appropriate stratification control is essential during the period (from early September to late October) in order to optimize embryo growth and development. While no increase of stratification rate was observed in seeds treated with 50 ppm of $GA_3$, significant increases were observed in seeds treated with 100 ppm of $GA_3$. At this concentration of $GA_3$, the stratification rate of Land race, Chunpoong and Yunpoong cultivar was 95.0%, 95.3%, and 96.5%, respectively.

• Korean Journal of Medicinal Crop Science
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• v.4 no.1
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• pp.12-18
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• 1996

This study was investigated to improve the rate of the seed germination of Wasabia japonica with $GA_3$ and BAP. The germination rate was 36% with 100ppm $GA_3$ only and 32% with 10ppm BAP only, while that was 65% with combination of 100ppm $GA_3$ and 10ppm BAP compared to that of 7.5% in control. This results show us that the most effect of germination rate was with 100ppm $GA_3$ and 10ppm BAP. Mutagenesis was induced with mutagen, EMS and colchicine. Before the germination, the survival rate was 62% with 0.5% colchicine compared to that of 7% in control. After the germination, the 85% of developed seed was alive with treatment of 0.5% colchicine and 55% of those was alive with 0.06% EMS compared to that of 8% in control. We analyzed the karyotype and isozyme pattern of Wasabia japonica induced with colchicine and EMS. The tetratype of Wasabia japonica was observed from Wasabia japonica treated with 0.5% colchicine. whereas it was not observed with 0.06% EMS. The peroxidase pattern of colchicine treated Wasabia japonica was different from nontreatment. but that of EMS treated Wasabia japonica was the same with normal one.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.1 no.1
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• pp.60-65
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• 1991

The hydrothermal growth of $GaPO_{4}$ Single Crystals was carried out by the horizontal temperature gradient method. The most promising solvents for the crystal growth of $GaPO_{4}$ are $H_{3}PO_{4}$ and HCl solutions. Single crystals have been hydothermally grown at temperatures over the range $210-290^{\circ}C$ in these solutions with seed crystals. The glowth rates in HCl solution were higher than that for comparable conditions in $H_{3}PO_{4}$ solution. Morphologies of crystals grown at temperatures below $200^{\circ}C$ tended to be bounded by small major rhombohedral(10$\bar{1}$1) faces. In the temperature range from 200 to $430^{\circ}C$, the single crystals have morphologies bounded by prism (10$\bar{1}$0), small major rhombohedral(10$\bar{1}$1) and minor rhombohedral(01$\bar{1}$1) faces at the early stage, and grew with well developed basal(0001) faces by increasing the growth temperature.