• Journal of Sericultural and Entomological Science
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• v.31 no.1
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• pp.1-11
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• 1989

To investigate changes of dry weight, C/N ratio, carbohydrate, ratein and nucleic acids in the barks of the hardwood cutting of mulberry plants, the barks of the hardwood cutting were taken every 10days from the cutting day to 40days after cutting. Results were summarized as follows : Growth of shoot and root in Keomseolppong (Morus bimbycis KoIDZ.) after cutting was better than that in kaeryangppon (Morus alba L.) and Daeryugppong(Morus Lhou(SER.) KoIDZ.). Dry weight in the barks of the hardwood cutting decreased up to 40days after cutting (decrease percentage of dry weight : about 14%) and Keomiseolppong showed the highest decrease precentage of dry weight. Change of C/N ratio decreased in the initiation, whereas that from 10days after cutting increased with the growth of new shoot, C/N ratio was the highest in Keomseolppong and the lowest in Kaeryangppong. Total sugar showed decreasing tendency up to 40 days after cutting the increase from 10 days to 20 days. Reducing sugar increased in the frist 20days, followed gradually decrease up to 40 days after cutting Starch levels decreased up to 40 days. Change in the content of starch closely paralleled to that of dry weight of bark of the hardwood cutting. Content of total sugar and starch in Keomseolppong was the highest, and was consumed more than that in the rest of varieties. Crude protein and soluble protein increased up to 10 days after cutting, followed decrease up to 40 days. Protein content of Keomseolppong was smaller than that in the rest of varieties. RNA content showed the same tendency with that of protein content, but Keomseolppong showed always the highest. Content of DNA did not show any change and difference among three varieties.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.5
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• pp.476-485
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• 1992

M1 plants which were produced from seed soaking in chemical mutagen, EMS or NaN$_3$, appeared wide morphorogical variations such as dwarf, albino, twisted leaf, white streaked leaf, and purpled stem. In mutants of reproductive organs, there were monoecious plants such as female-flower plant and male-flower plant, multiple spikes, and steriled plants among M1 plants. Also, barren stalk was increased significantly in M1 plants. Ear bagging at ear initiation stage prevented seed set on cob in normal plants. In spite of ear bagging, M1 plants which had cobs with seed set was 3.9-11.2% of stalks developed from seeds soaking with mutagens, but only three or four kernels could be matured on a cob. Ear bagging after mutagen injection into initiating ear produced 5.1-10% in cobs with seed set, but only 1.7-6.3 kernels could be matured. Cobs removed silk at four hours after artificial pollination increased the rate of cobs with seed set to 27%. Microscopic observation confirmed that ontogeny of kernels matured from ear bagging and mutagen treatment would be both adventitious and diplosporous apomictic reproduction. Chromosome set of M2 seedling was found to be diploid type in chromosomal counting of root tip. As M$_2$ plants showed an uniform appearence within each lines and their CV of plant height were ranged 4-6% in each lines, we concluded that they were apomictic progeny. But we could not find any marker traits combined with apomixis.

• Journal of Bio-Environment Control
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• v.17 no.4
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• pp.247-251
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• 2008

During a 35-day growth cycle, N, P, and K uptake was determined by measuring changes in their contents in culture solutions. At harvest, plants were separated into the roots, base organs and shoot, and dried for tissue analysis for N, P, and K. The uptake rates of N, P, and K followed cyclical patterns that was related to shoot development and harvest, but were independent of the transpiration rate. Uptake of N declined from 5.6 mmol $plant^{-1}$ $day^{-1}$ just prior to the cycle initiation to 4.0 mmol $plant^{-1}$ $day^{-1}$ at day 15. Uptake rate steadily increased as flower stems reached maturity up to 10.3 mmol $plant^{-1}$ $day^{-1}$ day 35. Uptakes rates of P and K followed similar patterns of N uptake. Tissue concentrations of N and P steadily decreased since day 15. Content of K was the lowest at day 20 and steadily increased thereafter. In the root tissue, N and K contents were the lowest at day 15, increased to day 30, and then decreased at day 35. Tissue P content was just a reverse of those of N and K.

• Proceedings of the Korean Society of Crop Science Conference
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• 2017.06a
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• pp.241-241
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• 2017

Sweet potatoes (Ipomoea batatas (L.) LAMK.,) have been cultivated in Central and South America for about 2000 years and are now grown mainly in Asia and South America. Sweet potatoes are annual in the temperate region, but are classified as perennial in the tropical region. In 2000, the cultivation area of sweet potatoes decreased to about 16,000 ha in 2000, but the cultivation area increased slightly in recent 20,000 ha in Korea. Sweet potatoes do not show higher maximum dry matter production of 120 ~ 150g per plant, and the leaf area index (LAI), which maximizes dry matter production, is known as 3.0 ~ 4.0. As the leaf area increase, the penetration of light into the canopy becomes poor, and sufficient photosynthesis cannot be achieved in the lower leaves, on the other hand the respiration increase, which results in poor dry matter production. This study was conducted to know the responses of sweet potatoes to intensive shading treatment of 80% shading. This experiment was conducted for about 42 days from September 6, 2016 to October 18, 2016 at Gyeongsang National University Experimental Farm, Jinju, Korea. The plant canopy was shaded with black nylon 80% shade cloth suspended 1.2 m above the ground. The photosynthetic rate, stomatal conductance, chlorophyll fluorescence, SPAD and NDVI were measured in 3 replicates every 7 days after shading initiation. After the fresh weight was measured, the samples were dried at $80^{\circ}C$ in a dry oven and measured. By the 80% shading treatment, chlorophyll fluorescence of the treated plants was slightly higher than that of the control, the SPAD value was higher by 3.4 and NDVI value was higher by 0.01. However, photosynthetic rate and stomatal conductance were lower than those of the control. The stomatal conductance of the control were two times higher than those of the control and the photosynthetic rate of the control was four times higher than that of the control. In control, plant showed a tendency to steadily increase in fresh weight and dry weight. However, in the case of shading treatment, the tendency to increase in the fresh and dry weight of tuberous roots was not clear. The fresh weight of shoot showed a tendency to increase steadily while the difference between treatment and control was not large, but tended to decrease after frost.

• Korean Journal of Soil Science and Fertilizer
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• v.7 no.2
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• pp.113-118
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• 1974

A study was carried out to investigate the effect of application time of fertilizer nitrogen on its rate of uptake and its distribution in rice plant. The rate of applied fertilizer was 100kg/ha, as a single application at transplanting time and four equal split applications of 25kg/ha was applied at transplanting time, 3 weeks after transplanting, 1 week before the primodial initiation stage of growth and at the flag leaf stage of growth, respectively. The ammonium sulfate was labelled with N-15, as 1% atom excess for single application and 4.4% atom excess for split applications. The results are sumarized as follows: 1. The effect of split application of nitrogen on yield was observed. The yield of brown rice of the single application at transplanting time was 3.1 ton/ha and the split application was 3.4 ton/ha. However, without nitrogen the yield was reduced to 1.9 ton/ha. 2. The number of grains per panicle and 1000 grains weight were increased as split application of nitrogen, but for the number of panicles per hill and maturing rate, the single application of nitrogen revealed favorable results. 3. The rate of uptake of applied fertilizer nitrogen showed a tendency that the efficiency of fertilizer nitrogen increased by top dressing. The rate of uptake of applied nitrogen as basal application, first top dressing, second top dressing and third top dressing was 28%, 33% 51% and 63%, respectively. 4. After shooting stage of the growth, nitrogen in straws transfered to grains. The nitrogen applied at flag leaf stage was absorbed by root and easily accumulated in grains rather than straw.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.57 no.2
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• pp.106-112
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• 2012

In order to understand the growth and ecophy -siological response of ginseng to global warming condition, we cultivated one and two year ginseng seedlings in control (ambient $CO_2$ + ambient temperature) and global warming treatment (elevated $CO_2$ + elevated temperature) from March 2010 to July 2011. Shoot appearance and initiation of flowering were advanced by 3-4 days in global warming treatment than in control. However, timing of fruit setting and seed ripeness was similar in both control and global warming treatment. Shoot length was longer in global warming treatment than in control, and also the number of leaves was much in global warming treatment. Fresh root weight was not different between control and global warming treatment. Photosynthetic rate was higher in global warming treatment than at control. Photosynthetic rate and transpiration rate were higher in two year seedlings than in one year seedlings at control, but was not different between seedling age of ginseng in global warming treatment. Water use efficiency was higher in one year seedlings than two year seedlings at control and global warming treatment. These results demonstrated that Korean ginseng more or less positively responds to global warming situation.

• Journal of Periodontal and Implant Science
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• v.28 no.2
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• pp.219-237
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• 1998

Numerous bone graft materials have been used in Periodontics, in an attempt to reach the main goal of periodontal therapy, i.e. the regeneration of periodontal tissue lost due to destructive periodontal diseases. The present study investigates the effect of composite graft of DFDB and Calcium sulfate with and without Calcium sulfate barrier in Periodontal 1-wall intrabony defects in dogs. Following the initiation of general anesthesia by I.V. administration of 40mg/Kg of Pentobabital, second premolar was extracted and full thickness flap elevated. The crown portion of premolars was removed. Exposed root canals were sealed with Caviton and covered completely with flap. After the healing period of 8 weeks, the surgical sites were re-opened and 1-wall intrabony defects were created, and treated with flap operation alone(control group), with composit graft of 80% DFDB and 20% Calcium sulfate(Experimental group 1), with composite graft of DFDB and calcium sulfate with calcium sulfate membrane( Experimental group 2). Healing response was histologically observed after 8 weeks and the results were as follows : 1. New bone formation was 70 % in the control group, 93 % in the Experimental group I, 89 % in the Experimental group II. There was a no differences between Experimental groups. 2. New cementum formation was not significantly different between control and two Experimental groups. 3. The length of connective tissue adhesion was 30 % in the control, 7% in the Experimental group I and 11 % in the Experimental group II. 4. After 8weeks, calcium sulfate was completely resorbed, while DFDB particle remained. These results suggest that the use of composite graft of allogenic DFDB and Calcium sulfate with and without Calcium sulfate barrier in periodontal 1 wall intrabony defects have little effect on connective tissue adhesion, but has beneficial effect on new alveolar bone and new cementum formation, and prevent downgrowth of epithelium and connective tissue effectively.

• Korean Journal of Plant Tissue Culture
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• v.25 no.3
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• pp.195-200
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• 1998

Callus induction from leaf and stem explants of Arabidopsis thaliana was successfully obtained when leaf explants were cultured on MS medium containing 2.0 mg/L 2,4-D in the dark and also, when stem explants were cultured on CP medium containing 0.5 mg/L 2,4-D and 0.1 mg/L BAP. Explant-derived sliced calli were suspension-subcultured every week in CP liquid medium with 0.5 mg/L 2,4-D and 0.1 mg/L BAP in the dark, and shoot-forming cell clusters of nodular, pale yellow and knobby type were selected after 7-8 weeks of culture. Shoots were initiated from the green spots of the selected shoot forming calli cultured on MS regeneration medium containing 0.05 mg/L IAA, 7.0 mg/L 2-iP and 30 g/L sucrose under continous illumination for four weeks. Shoot regeneration frequency (calli regenerating at least one shoot) was more than 50%. For plant regeneration, excised shoots were trnasferred to hormone free medium for root initiation after 4 weeks of culture. The regenerants were bolting after 2 weeks of culture and formed in vitro flowering buds within bracts after 4 weeks of culture.

• Journal of Korean Society of Forest Science
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• v.70 no.1
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• pp.45-54
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• 1985

The experiment was conducted to test the effects of ectomycorrhizal inoculation and soil moisture regime on growth and nutrient uptake of Pinus rigida seedlings. Two-year-old seedlings inoculated with either Pisolithus tinctorius or Thelephora terrestris were used for this experiment. There were two moisture treatments and four phosphate treatment levels with three replications. Height and root collar diameter growth and dry weight increase were measured and nitrogen, phosphorous, and potassium in the tissue were analyzed three months after the initiation of phosphate and moisture regime treatment. Results are as follows; 1) Height growth of seedlings was not affected in all treatments. (mycorrhizae, fertility, moisture). 2) High moisture regime increased root collar diameter growth 2.7 times as large as low moisture regime. 3) In low moisture regime, net production increased 26% in seedlings inoculated with Pisolithus tinctorius and increased 72% control seedlings. 4) In high moisture regime, net production of inoculated seedlings with Pisolithus tinctorius increased four times as much as that of control seedlings but increased $P_2O_5$ in fertility level did not affect net production. 5) In uptake of nitrogen, phosphate, and potassium, Pisolithus tinctorius - inoculated seedlings increased uptake by 1.9, 1.8, and 1.5 times, respectively, as much as control seedlings. 6) Increase in $P_2O_5$ fertility level enhanced the uptake of $P_2O_5$ in Pisolithus tinctorius - inoculated seedlings, but not affected the uptake of $P_2O_5$ in control seedlings. 7) Increase in $P_2O_5$ fertility levels enhanced the uptake of $K_2O$ in Pisolirhus rinctorius - inoculated seedlings.

• Korean Journal of Weed Science
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• v.12 no.3
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• pp.200-222
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• 1992

The results of recent researches for improvement of seedling stand in direct seeded rice on the dry paddy in Korea were summarized as the following ; a variety to be cultivated should be chosen the characteristics of high percentage germination under low temperature, shorter period of shoot emergence, and better growth of the mesocotyl and shoots. Meanwhile, there was 40% increase in seedling stand at the treatment of removal of the seed awn under using the drill seeder. After seeding the rice seed covered with soil of 3cm depth was better seedling emergence and also there was the hightest seedling emergence at the 70% of moisture content of the soil. In addition, the application of the Release containing GA 10% enabled to increase the seedling stand and furthermore it was effective under deep seeding depth. The optimum seeding date should be seeded around May 10 when mean air temperature is above 12-13$^{\circ}C$ so that may establish more less 70% in seedling stand. Based on an appropriate seedling stand of 150/$m^2$, the optimum seeding rate was 5kg/10a. It was the best in seeding method using drill seeder and the most desirable recommended seeding method was the drill seeder in terms of seedling stand. In order to improve seedling stand water management was more effective in canal irrigation and in drainage at 6hr after irrigation following by the seeding process. On the other hand, for the increase of seedling stand under flooded condition a variety might have characters being better germination at low concentration of dissolved oxygen and vertically deeper growing of the crown root. Also, seedling stand was able to increase with the seed coating of $CaO_2$in the flooded soil. It was possible to be seeded on the early part of May being mean air temperature of avove 10$^{\circ}C$ and the optimum seeding rate was 5kg/10a. For an effective water management water would be flooded up to 3cm depth for 2-3 weeks after seeding. The rice plant grown under the direct seeded cultivation might be not so much strong in lodging resistance compared to that grown under the transplanting and moreover direct seeded rice cultivation under flooded condition would be more weak growth of the rice plant than that on dry paddy. Meanwhile, the lodging would be affected by the seeding rate, the soil depth after seeding. and seeding method even in the same variety. In particular, roots in the lodging pattern of direct seeded rice cultivation under flooded condition were largely distributed on the soil surface so that resulted easily in the lodging. In general, the lodging resistance would be greater as seeding rate and amount of N fertilizer application are lower and soil depth after seeding is higher. Among the introduction of different seeding method the high ridged drill seeding method on dry paddy soil resulted in the lowest in the lodging index and also it was lower in the drill seeding method than in the scattering seeding method under flooded condition. In case of more than 150 seedlings per $m^2$ there was a severe lodging due to high lodging index at the 3rd and 4th internodes. The effective lodging prevention was able to at the treatment of the Inabenfide at 45 days before heading and the Uniconazol at 15 days before heading which caused the shortage by 10-15cm in culm length. Also, fertilizer management using split application of nitrogen would be contributed the reduction of lodging at the rate of 20-30-20-20-10%(basal-5th leaf stage-7th leaf stage-panicle initiation stage-heading stage) on the dry paddy soil.