• Korean Journal of Environmental Agriculture
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• v.14 no.3
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• pp.329-337
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• 1995

The effect of N-(4-chlorophenyl) maleimide(CPMI), plant growth regulators, and alkylating agents on gluathione(GSH) content and glutathione S-transferase(GST) activity was examined with 3-day-old etiolated sorghum(Sorghum bicolor [L.] Moench) seedlings. The GSH content and GST activity of untreated seedlings were higher in shoots than that in roots. Response of GST activity in coleoptile was significantly greater than in other tissues of sorghum seedling. In CPMI-treated seedlings, GSH content was not significantly different from that in untreated seedlings. CPM treatment resulted in 2.3-fold increase in GST activity measured with metolachlor as substrate in the coleoptile region. In contrast, change in GST activity measured with metolachlor as substrate in the coleoptile region. In contrast, change in GST activity measured with 1-chloro-2, 4-dinitrobenzene did not occur. The increase of GST activity was caused by induction of a GST isozyme, which is substrate-specific to metolachlor. Subsequently, two hypotheses related to metolachlor detoxification were evaluated on the basis of regulation of plant growth regulators and substrate induction of GST activity. In coleoptile, GST activity measured with metolachior was increased to 2.1-and 3.4-fold by both 2, 4-dichlorophenoxyacetic acid(2,4-D) and metolachlor treated at the germination stage of sorghum, respectively. Treatments of 2.4-D and metolachlor also induced isozymes exhibiting the activity toward metolachlor. One of the isozymes was co-eluted with that induced by CPMI. These results indicated that increase in GST activity by CPMI may be partially related to auxin regulation and substrate induction.

• Journal of Life Science
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• v.16 no.3 s.76
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• pp.493-499
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• 2006

In this study, we investigated the effect of growth regulators, seed priming, and light condition for the germination and early growth in Snapdragon (Antirrhinum majus L.). The optimum concentration of growth regulator for the promotion of germinability turned out to be 250 uM of $GA_3$. The germination enhancement in combination of $GA_3+BAP$ was not significant. The optimum priming condition for the maximum germinability was 2 day treatment of 200 mM of $KNO_3$. which increased germination by 14% and shortened the day to germination by 3.5 days. The optimum temperature for germination was $15{\sim}25^{\circ}C$. The germination frequency was decreased to lower than 20% at $30^{\circ}C$, which showed that seeds of Snapdragon germinates better at low temperature than high temperature. The germination frequency was different at light condition; it was low at dark condition, but was increased by $15{\sim}20%$ at red light condition. The combination of $GA_3$ and seed priming showed better germinability than the single treatment of $GA_3$ and seed priming.

• Horticultural Science & Technology
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• v.28 no.4
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• pp.552-560
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• 2010

$GA_{4+7}$+BA, a plant growth regulator for induction of feathering in young apple tree and increasing fruit size, was applied by various methods on 'Gala'/M.9 apple trees in high density orchard for 4 years to investigate its effect on fruit and shoot growth. $GA_{4+7}$+BA($80-300mg{\cdot}L^{-1}$) increased fruit length, fruit weight, and L/D ratio regardless of application methods, but it did not affect soluble solid content, acidity, leaf area, and chlorophyll. Seed number was not affected by $GA_{4+7}$+BA application, however, more immature seeds was observed in treated 'Gala' fruit. Shoot growth was increased when spraying $GA_{4+7}$+BA at tree crown but not affected when spraying at fruit directly. More significant fruit growth was observed when $GA_{4+7}$+BA was applied on the fruits between late of May and early of June when fruit cell division ended; however, high concentration of $GA_{4+7}$+BA resulted in lower fruit storability because of lower firmness. Hence, more attention should be paid when applying high concentration of $GA_{4+7}$+BA to small sized fruit cultivars like 'Gala'.

• Journal of agriculture & life science
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• v.45 no.4
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• pp.73-80
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• 2011

This study was conducted to elucidate the best cutting condition in propagation of Juniperus chinensis var. sargentii in respect of survival rate, rooting rate, and early growth after cutting via process of cutting time, cutting media, cutting type and growth regulators. As for cutting time, rooting rate was 68.3% on April, which was higher than 39.5% on May and 32.5% on June. The best cutting media was stream sand of rooting rate 72.7%. Those of mixed soil and decomposition were 40.1% and 27.5% each. The effect of growth regulators was different according to the kind of cutting media. There was no effect on stream sand media which showed the highest rooting rate, while it was very effective on the media of decomposition of granite, which rooting rate showed the lowest. Hardwood as cutting materials showed somewhat higher survival and rooting rate compared to semi-hardwood. The cutting with hardwood condition to stream sand on April, it is regarded to be the most effective condition for Juniperus chinensis var. sargentii to increase survival and rooting rate. Therefore in this experiment it is considered that the best season cutting is April, and the most useful media and plant materials stream sand, and hardwood respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.41 no.4
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• pp.465-474
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• 1996

The study was carried out to determine the proper concentration of plant growth regulator, kinetin on alleviating copper toxicity for two rice cultivars of seed germination. The results were as followings : Soaking treatment of kinetin 10$^{-3}$ M increased the germination rate of both cultivars, Ilpumbyeo and Hyangmibyeo 1 by 92% and 88% as compared with copper treatment (60ppm). But the soaking treatment effect of plant growth regulator, kinetin was not recognized at the kinetin 10$^{-4}$ M and 10$^{-5}$ M. Chlorophyll content of both rices was higher than that of Hyangmibyeo 1. Copper content of Ilpumbyeo was higher in leaf than in seed part. At the 3 days after treatment of copper 60ppm, both cultivars of treatment of kinetin 1O-3M showed the somewhat thin bands at the 35 and 40kDa compared with others. A new protein band pattern was only appeared to kinetin 1O-3M at approximately 54.4kDa(M. W) at the 7 days after treatment of copper 60ppm in llpumbyeo cultivar, SOD activity of copper 60ppm treatment increased in 3DAT, but there were no significant differences in 5 and 7DAT of two cultivars. Free proline contents of copper 60ppm treatment in llpumbyeo were remarkably increased about 4.996$\mu$M. In particular, free proline content of kinetin l0$^{-3}$ M in Ilpumbyeo was 5.008$\mu$M in 3DAT. In case of Hwangmibyeo 1, free proline content of copper 60ppm was 5.825$\mu$M compared with an untreated control showing 2.34l$\mu$M. The effects of kinetin treatment were recognized to promote the root growth and germination rate under copper toxicity(60ppm) condition in both cultivars.

• Journal of Bio-Environment Control
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• v.19 no.4
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• pp.397-402
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• 2010

This study was conducted to find out the appropriate type and concentration of plant growth regulator for mass production of wild type Hydrangea serrata. And the optimal soaking time for rooting of the cuttings was also investigated. When the cuttings of Hydrangea serrata were cultivated for 6 weeks after immersing in $50mg{\cdot}L^{-1}$ of IBA for 3 hrs, the number of roots was 90.6. However the number was significantly decreased when the cuttings were treated with $10mg{\cdot}L^{-1}$ of IBA. The rooting ratio was 100% when the cuttings was immersed in 1,000, 2000 and $3000mg{\cdot}L^{-1}$ of NAA solution for 5, 3 and 10 sec., respectively. Despite the perfect rooting, the number of roots was decreased. The number of roots was 105.5 when the cuttings were treated in $2,000\;mg{\cdot}L^{-1}$ of NAA for 5 sec., which was the highest number in NAA treatment. Overall, the rooting ratio and growth was better when the cutting was treated with low concentration of IBA ($50{\sim}250\;mg{\cdot}L^{-1}$) than the treatment of NAA. And the most appropriate concentration and time fot the treatment of IBA was $50mg{\cdot}L^{-1}$ and 3 hrs, respectively.

• Journal of Plant Biotechnology
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• v.39 no.4
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• pp.288-294
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• 2012

In order to establish an efficient adventitious shoot regeneration conditions from leaf explants for Asian pear 'Whangkeumbae', the effect of concentration and kinds of plant growth regulator and carbon source was investigated. Leaf explants of cultures grown on Murashige and Skoog (MS) medium containing 8 g/L plant agar were used. When the medium contained 0.25 mg/L thidiazuron (TDZ) and 0.3 mg/L indolebutyric acid (IBA), the adventitious shoot regeneration rate (ASRR) was greater as 61.1% than others treated and higher TDZ concentrations (2.5 and 5 mg/L) treatment significantly reduced the ASRR. As the effect of IBA and indoleacetic acid (IAA) concentration on the ASRR, 0.5 mg/L TDZ plus different concentration of IAA exhibited relatively high ASRR and 0.5 mg/L TDZ plus 0.3 mg/L IAA showed the highest ASRR of 76.7%. Also the effect of sucrose and sorbitol as carbon source on regeneration was examined. The highest ASRR and the most shoots per explants averaged 94.4% and 3.49 by treatment of 30 mg/L sorbitol, respectably. Sorbitol is considered better carbon source than sucrose for shoot regeneration of 'Whangkeumbae' pear.

• Horticultural Science & Technology
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• v.33 no.2
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• pp.186-195
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• 2015

This research was conducted to investigate effect the plant growth regulators (PGRs) on the characteristics of fruit and flesh softening, using GA3 and thidiazuron (TDZ) treatments in 'Heukboseok' grapes. The total yield obtained under PGR treatment was 88.3% lower than the target production when a single treatment with $GA_3$ of low concentrations was used, but the expected yield was recovered by combined treatment with TDZ and $GA_3$. When harvested on the basis of color, the harvest rate up to 100 days after full bloom (DAFB) was low with the $GA_3$ single treatment, but was increased by the addition of TDZ, with the second TDZ mixed treatment being particularly effective. The soluble solids content in the PGR-treated samples demonstrated no significant changes after 90 DAFB, while the acidity content decreased rapidly starting from 90 DAFB. Measured on the basis of sugar and acidity content, maturity was reached much earlier in treated fruit than in the non-treated fruit. Firmness was maintained at a higher level until the final harvest time after PGR treatment compared to untreated grapes according to epidermis thickness and flesh density increase to activity cell division and expansion by $GA_3$ and TDZ. In particular, the fruit quality was improved based on the delay of softening in primary and secondary treatments of $25mg{\cdot}L^{-1}\;GA_3+2.5mg{\cdot}L^{-1}$ TDZ. The production of seedless fruit was difficult, even with the inclusion of TDZ, reaching the highest seedless rate of only 65.5%. Fruit cracking was rare, occurring at a rate of about 0.0~0.9% in all treatments. Accordingly, 'Heukboseok' grapes should be harvested within 100 days after full bloom (DBFB) before a rapid decrease of firmness, conferred by primary and secondary treatments with $25mg{\cdot}L^{-1}\;GA_3+2.5mg{\cdot}L^{-1}$ TDZ.

• FLOWER RESEARCH JOURNAL
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• v.17 no.2
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• pp.93-100
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• 2009

This study was carried out to investigate the efficient in vitro mass propagation methods for juvenile sporophytes of Matteuccia struthiopteris. Chopped segments of pinnae, petiole and rhizome were cultured on 1/2MS with 0.1% activated charcoal. Among these explant sources only rhizome segments produced young sporophytes, regenerating vigorously on 1/2 MS medium. Adjusting sucrose concentration to 2% and supplement to $50mgL^{-1}$ $NaH_2PO_4$ in 1/2MS medium proved to be more efficient for plant regeneration. Various combinations of growth regulators such as kinetin, BA, NAA, and IBA were added to the growing media, and the best sporophyte regeneration was obtained by $1{\mu}M$ kinetin. The BA addition resulted in vigorous proliferation of meristematic tissues, but without differentiation to sporophytes. Three types of culture methods, solid using agar, liquid stationary, and liquid shaking culture, were employed with or without activated charcoal. The addition of 0.1% activated charcoal to modified 1/2MS media (2% sucrose, $50mgL^{-1}$ $NaH_2PO_4$, $1{\mu}M$ kinetin, pH 5.8 and 0.8% agar) yielded highest sporophyte regeneration in liquid shaking culture.

• Asian Journal of Turfgrass Science
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• v.24 no.2
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• pp.156-160
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• 2010

This study was performed to provide useful information for kentucky bluegrass management during summer by application of plant growth regulator, Trinexapac-ethyl. Visual quality, shoot density and chlorophyll contents of treatment blocks were significantly different from those of control during summer by application of Trinexapac-ethyl. The turfgrass density of treatment was increased of 4ea/$10\;cm^2$, especially about 5ea/$10\;cm^2$ during the growth retarded period of June and July. Chlorophyll contents index and visual quality of kentucky bluegrass were improved by application of Trinexapac-ethyl during summer, too. In addition, the occurrence of foliage in rainy and high temperature season was less than that of control. However, there was no significant difference in the root length of Kentucky Bluegrass. Meanwhiles, mowing height of kentucky Bluegrass was suppressed by 38% at 2 WAT week after treatment and that there was no significant growth of treatment at 4 WAT. In this experiment, turfgrass quality was significantly better than that of control during July, even though trinexapac-ethyl wasn't applied at all in July. Consequently, periodic treatment of trinexapac- ethyl from spring would be very important to promote the turfgrass visual quality during summer which is unfavorable season on the growth of kentucky bluegrass. And it is possible to reduce mowing times at least 30% for 2 weeks by one application of Trinexapac-ethyl 0.02~0.03 ml/$m^2$ in kentucky bluegrass fairway. Additively, trinexapac- ethyl treatment can be helpful environmentally by cutting down the fertilizers and pesticides in golf course.