• Korean Journal of Materials Research
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• v.3 no.6
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• pp.678-683
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• 1993

Atomic arral1gement of ordered phase in $GaAs_{0.5}Sb_{0.5}$ epilayer was studied by observation of selected area diffraction patterns and high resolution images. The epilayer was grown on untilted (001) GaAs substrate at $580^{\circ}C$ by molecular beam epitaxy(MBE). A 1/2(111) type long-range ordered phase is formed in the epilayer. Atomic arrangement of the ordered phase is described as an alternative stacking of As-rich and Sb-rich {111} planes in group V sublattice. Space group of the ordred structure belongs to R3m, and unit cell of the ordered structure is rhombohedral.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.42 no.4
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• pp.384-391
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• 1997

In the cultivation of Bupleurum falcatum, one of the problems to surmount is long-term germination period and unstable germination. This experiment was done to examine the effect of $GA_3$ concentration [0(water), 0.01, 0.lmM], chilling, their treatment period [2, 4, 8 days ($GA_3$) : 0, 2, 4 weeks (chilling)] and light quality (red, white, dark) given during the period as pretreatment before sowing on the seed germination of its two cultivars (cv. Jaerae, cv. Jangsu). Light treatment was given during all the periods of $GA_3$ treatment or for 0, 2, 4 days at the end of the chilling treatment. There was no difference in the mean germination rate between the levels of all the treatments except the $GA_3$ concentration meaning that water imbibition and $GA_3$ treatment had the same effect. As light quality treatment during the water imbibition was forced, the mean germination rate of Jaerae, 2 to 4 days imbibition period or red light was more increased or accelerated compared to the other levels of the same treatment, respectively. The rate of Jaerae not affected by the light quality was the greatest in the 2 days water imbibition while the rate of Jangsu was the greatest when water-imbibed for 4 days or treated by red light. No chilling before sowing showed the highest rate due to the light quality and white light forced after sowing had greater rate than the dark treatment. Although there was no difference between the rates of light quality treatment levels in the condition of no chilling before sowing and white light treatment after sowing, the rate of Jangsu was enhanced or accelerated only under illumination during 2 days water imbibition before sowing.

• Korean Journal of Medicinal Crop Science
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• v.5 no.3
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• pp.169-176
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• 1997

Gibberellin (GA) has been widely used to break seed dormancy for better stand establishment. The experiment was done to clarify the effect of $GA_3$ (concentration; period) and light quality (red; white; dark) after sowing on seed germination and radicle elongation of Campanulaceae (Platycodon grandiflorum; Codonopsis lanceolata; C. pilosula) to get an information on their field emergence. The germination test was carried out with 12 hours irradiation for 9 days after priming treatment. In the darkness, the mean germination rate of all the species was decreased in the order to P. grandiflorum, C. lanceolata, C. pilosula. Their mean germination rates and radicle lengths were increased with increased concentration to 0.1mM of $GA_3$. Earlier germination rate was higher but later one was less in 4-day $GA_3$ treatment than in 1- or 2-day $GA_3$ treatment. Light treatment. especially red light given after $GA_3$ treatment. eliminated the $GA_3$ treatment effect. Red light done after $GA_3$ treatment nearly blocked the germination of P. grandiflorum and C. pilosula but delayed that of C. pilosula compared to the other light quality treatments having the similar rate. In addition. the radicle elongation of all three species affected by light quality treatment showed the same result as the germination rate.

• Journal of Bio-Environment Control
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• v.27 no.4
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• pp.407-414
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• 2018

This study was aimed to evaluate the effect of application method and concentration of gibberellin $A_3$ ($GA_3$) on the growth, runner production, and seedling quality of strawberry plants (Fragaria ${\times}$ ananassa Duch. cv. Maehyang) during nursery period. The mother plants of strawberry were transplanted in pot ($64{\times}27{\times}18cm$) filled with commercial growing medium on March 20, 2018. $GA_3$ concentration was applied as 0, 50, 100 or $200mg{\cdot}L^{-1}$ with spray or drench to 45 mL per plant at 4 weeks after transplanting, respectively. Nutrient solution was supplied with the EC $1.5dS{\cdot}m^{-1}$ after the transplanting and supplied 350 mL per pot twice a day (15 min per one time) after rooting. The growth characteristics of mother plants of strawberry were measured at 7 weeks after treatment, and growth characteristics of daughter plants of strawberry were measured at 10 weeks after treatment. Runner length and diameter of mother plant was the longest or thickest in the spray with $200mg{\cdot}L^{-1}$ than the other treatments, respectively. Soil-plant analysis development (SPAD) value of mother plant was the lowest in spray with $200mg{\cdot}L^{-1}$. However, leaf length, leaf width, and crown diameter showed no significant differences in all treatment among application method and concentration of $GA_3$. As the concentration of $GA_3$ increased, physiological disorder like stretchiness of crown occurred more. The physiological disorder was the most occurred in spray treatment with $200mg{\cdot}L^{-1}$, but drench treatment occurred less than spray treatment. The number of runners and daughter plants increased with increasing concentration of $GA_3$ regardless of application methods. In the growth characteristics of the daughter plants, leaf length and leaf width of first daughter plant, plant height, crown diameter, leaf area and SPAD value of second daughter plant, and plant height of third daughter plant were the significantly greatest in drench with $100mg{\cdot}L^{-1}$ treatment. This results indicate that growth and runner production of mother plants and growth of daughter plants of strawberry were the best achieved by drench application in the $100mg{\cdot}L^{-1}$ $GA_3$.

• Microbiology and Biotechnology Letters
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• v.2 no.3
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• pp.141-147
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• 1974

The cultural conditions for L-glutamate production were investigated using Brevibacterium flavum nov. sp. D2209B, the most productive strain among 5 strains reported in preceeding paper. A temperature of 3$0^{\circ}C$ and a medium volume of 30 ml per 500-flask were selected as standard culture conditions. And the following results were obtained. 1. When the concentration of acetate in the medium was below 30 g per litre, the maximum amount of L-glutamate was accumulated. 2. KH$_2$PO$_4$, MgSO$_4$, FeCI$_3$ and MnCI$_2$ were required for the L-glutamate poduction, but the concentration of those inorganic salts little effected. 3. Signifcant amount of L-glutamate was accutnulated in the limited biotin concentration less than 0.3 ug per litre. 4. The addition of malic acid or succinic acid enhanced the accumulation. 5. The L-glutamate accumulation was related to the incubation time of seed; the amount of L-glutamate accumulated was maximum by inoculating 16-20 hour incubated seed. 6. In the medium containing sufficient amount of biotin for growth, L-glutamate accumulation was stimulated by the addition of penicillin at appropreate time during incubation.

• Current Research on Agriculture and Life Sciences
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• v.11
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• pp.31-41
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• 1993

The biochemical effects of ABA and $GA_3$ on rice seedling stages were investigated from two rice cultivars, Dongjinbyeo and Samgangbyeo. Some of the results obtained are as follows ; The shoot growth was significantly increased at all concentrations of $GA_3$ compared to the control but it was completely inhibited by ABA. The root length was not affected by all concentrations of $GA_3$ except for the highest concentration of $10^{-3}M$. ABA had an inhibitary effect on root growth and showed similar trend to the shoot growth. By increasing the concentration of $GA_3$, sugar content of rice seedlings was increased and starch content was decreased. On the contrary, the treatment of ABA revealed that sugar content was decreasing with higher level of starch content. Chlorophyll content was greatly reduced at the all concentrations of $GA_3$ in both cultivars tested. Generally, the responses of root activity decreased with treatment of $GA_3$ but no difference in the activity was observed in Samgangbyeo. Major fatty acids of rice seedlings were investigated as palmitic, oleic, and linoleic acid with little contents of linolenic acid and stearic acid. The contents of these fatty acids were decreased with ABA and increased with $GA_3$ treatment, respectively. A protein band of 24 kD in the electrophoresis was observed with ABA treated rice seedlings but not with $GA_3$.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.4
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• pp.297-303
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• 1993

Seedling emergence and .stand establishment in dry-seeded rice is unstable at present due to deep seeding, low temperature at seeding time, excessive drought or raining etc. This experiment was conducted to elucidate the effect of gibberellic acid(GA$_3$) on the seedling emergence and growth in dry-seeded rice. GA$_3$, IBA and Metalaxyl were treated by seed-soaking or-spray. Hwaseongbyeo, a japonica rice, was used. The seed-soaking treatment with GA$_3$ significantly increased the seedling emergence and plant height as compared with untreated seed. However, no difference was observed in IBA and Metalaxyl treatment. The optimum concentration of GA$_3$ to promote the seedling emergence and growth in dry-seeded rice was about 100ppm for seed-soaking and about 200ppm for seed-spray treatment. The seed-spray treatment of GA$_3$ with 200ppm promoted earlier and faster seedling emergence and elongated seedling height as compared with untreated seed.

• Proceedings of the Korean Society of Crop Science Conference
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• 1991.05a
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• pp.44-45
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• 1991

• Journal of Practical Agriculture & Fisheries Research
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• v.16 no.1
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• pp.55-66
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• 2014

This study has been conducted to investigate the treatment time and concentration of GA₃ solution dipping for labor saving in 'Campbell Early' grapevine. The rachis growth at harvest was reduced by GA₃ solution dipping before 5 days flowering, and increased significantly by GA₃ solution dipping treatment at full bloom and after 5 days full bloom. GA₃ 5, 10, 20 mg·L^-1 dipping treatment before 5 days flowering and GA₃ 20 mg·L^-1 treatment of full bloom and after 5 days full bloom showed a rachis twist phytotoxicity symptom. The optimum GA₃ concentrations for rachis growth promotion without phytotoxicity were 5 mg·L^-1 and 10 mg·L^-1. The degree of compact berry, bloom, skin color, SSC and acidity at harvest by GA₃ solution dipping treatment time between concentration were not different from those of control. But the fruit berry weight was decreased by before 5 days flowering treatment when compared with control. There were no differences in full bloom and after 5 days full bloom treatment. The occurrence percent of berry cracking at before 5 days flowering and after 5 days full bloom treatment were significantly increased by GA₃ treatment. The bitter rot occurrence of berry at harvest was not affected by GA₃ treatment. Total rachis length of fruit cluster was increased by full bloom and 5 days after full bloom treatment. The length of rachis increased without reference to them position at full bloom and 5 days after bloom treatment. Accordingly, GA₃ 5 mg·L^-1 solution dipping treatment at full bloom and 5 days after full bloom were can be effectively for rachis growth promotion.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.38 no.3
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• pp.213-218
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• 1993

An experiment was carried out to investigate the effects of plant growth regulators on the growth and fiber yield of ramie. Gibberellin (GA) and Atonic acid were applied at the various levels of application dates, application frequencies and concentration. Stem growth of ramie increased greatly by applying GA on the meristem of shoot apex. Among three treatments of application frequencies of GA, that is, one time application at the stage of stem length with 50cm, twice applications at the stem length of 50cm and 100cm, and three times applications at stem length of 50cm, 100cm and 150cm, stem growth increased more as application frequency increased. GA application is more effective on stem growth at the later stage of growth than the earlier growth stage. GA treatment of 100 to 300 ppm is more effective on stem elongation than 50 ppm, which was due on the elongation of internodes without increase in number of nodes. One time application of GA enhanced leaf growth more or less regardless of concentration, but GA was applied more frequently, leaf growth was inhibited more at higher concentration. Fiber yield was the highest at the treatment of three times application of GA with 100 ppm. This treatment also showed the highest percentage of fiber with 5.3%, which is much higher value compared with that of control treatment with 4.6%. Atonic acid was less effective on stem elongation than GA, but it also seemed to be effective on the enhancement of fiber development.