• Horticultural Science & Technology
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• v.35 no.4
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• pp.431-438
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• 2017

This study investigated the effect of pre-planting nitrogen (N) fertilization levels added to a soilless root medium on the growth of 'Dotaerang Dia' tomato seedlings. The N levels were varied for a total of 7 treatments: 0, 100, 250, 500, 750, 1,000, or $1,500mg{\cdot}L^{-1}$. The pH of the root media gradually rose in all treatments as the seedlings grew; however, the differences in the pH were not significant among the treatments. The electrical conductivity (EC) of the root media was significantly different among the treatments from sowing to week three, then drastically decreased after week four, which diminished the differences in the EC among the treatments. At week six, plant height, leaf length, leaf width, number of leaves, and fresh and dry weights of the shoot were highest for the treatment with $500mg{\cdot}L^{-1}N$. In contrast, the treatment with $1,500mg{\cdot}L^{-1}N$ had the lowest results for all growth measurements. The fresh weight was 67% heavier in the $500mg{\cdot}L^{-1}N$ treatment compared to the $1,500mg{\cdot}L^{-1}N$ treatment. The total N content in the tissues was lowest in the treatment with $0mg{\cdot}L^{-1}N$ and highest in the treatment with $1,000mg{\cdot}L^{-1}N$. The contents of calcium (Ca), magnesium (Mg), and metal micronutrients in the tissues were highest in the $250mg{\cdot}L^{-1}N$ treatment. A previous study demonstrated that adjusting the fertilization level to promote growth to over 90% of the maximum growth is a good strategy for lowering production costs and preventing damage due to excessive fertilizer absorption by crops. Our results indicated that the optimal pre-planting N fertilization level for tomato plug seedlings should be lower than $500mg{\cdot}L^{-1}$ and the optimum tissue N contents should be around 3.21% to 4.60%.

• Korean Journal of Medicinal Crop Science
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• v.16 no.2
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• pp.124-130
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• 2008

This experiment was conducted to investigate the optimum nitrogen fertilization conditions for the production of high-quality Rhodiola rosea L. in forcing culture. Up until 48 kg N/10 a of both urea and ammonium sulfate, dry matter yield of root of Rhodiola rosea L. tended to increase with increase in application rates, however, it decreased thereafter in higher application rates. In the case of urea, the content of salidroside in the root of the Rhodiola rosea L. appeared to decrease rapidly from the application rates of 64 kg N/10 a and over. Meanwhile, the content of salidroside in the root tended to decrease gradually with the application rates exceeding 64 kg N/10 a of ammonium sulfate. The optimum fertilization rates of urea and ammonium sulfate was 45-8-20-10-10 (N-P-K-Ca-Mg) kg/10 a according to the curvilinear regression equation. However, considering the nitrogen accumulation in soil, nitrogen translocation into the plant, and dry matter yield and content of salidroside in the root of Rhodiola rosea L., the optimum fertilization rates of urea and ammonium sulfate would be 40-8-20-10-10 kg/10 a and 35-8-20-10-10 kg/10 a, respectively.

• Korean Journal of Ichthyology
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• v.28 no.4
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• pp.260-266
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• 2016

We determined the morphologic characteristics (body weight and abdomen inflation degree) of the mother fish of sevenband grouper, Epinephelus septemfasciatus producing the healthy eggs. Experimental fish were chosen from the reared fish in the sea cage for 6 years. The fish were divided into four size groups by body weight: 4.0~5.0, 5.0~6.0, and 6.0~7.0 kg and four stages (I~IV) by the abdomen inflation degree. After hormone treatment, we observed the ovulation amount of induced eggs, rate of buoyant, fertilization, embryonic survival, and hatching. Egg and oil globule diameter was measured. In order to observe gonadal development, we calculated gonadosomatic index (GSI) and conducted its historical analysis. The ovulation occurred from all experimental fishes over 5.0 kg. The rate of buoyant, fertilization, and embryonic survival was the highest in 6.0~7.0 kg. Hatching rate was the highest in 5.0~6.0 kg. Stage I and II did not induce ovulation. GSI was $0.31{\pm}0.10%$ in stage I, $0.74{\pm}0.25%$ in stage II, $4.68{\pm}0.40%$ in stage III and $6.86{\pm}0.12%$ in stage IV. The rate of buoyant, fertilization, embryonic survival and hatching was the highest in stage III.

• Clinical and Experimental Reproductive Medicine
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• v.27 no.3
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• pp.261-265
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• 2000

Objective: This study was performed to evaluate the influence of maternal age on embryo quality and the frequency of multiple pregnancy in IVF-ET program. Method: 86 conventional IVF-ET cycles were divided into three groups according to the age by 5 year (group A: 26-30, group B: 31-35, group C: 36-40 yrs). The in vitro fertilization and development outcome (fertilization, cleavage and high quality embryo rate) and the pregnancy outcome (pregnancy, implantation, G-sac/high quality embryo and multiple pregnancy rate) were examined. And then, these results were compared among the groups. Results: The rates of fertilization (62.7, 68.5 and 65.4%, respectively) and cleavage (95.6, 97.6 and 98.0%, respectively) were not different among the groups. And the high quality embryo (HQE) rate also was not different among the groups (61.8, 62.9 and 62.8%, respectively). The pregnancy rate of group C (23.3%) was significantly lower than that of group A (41.2%) and B (48.7%). And the implantation rate was significantly decreased with advance in maternal age (group A; 17.3%, B; 12.6% and C; 6.0%). The G-sac/high quality embryo rate was significantly higher in group A (70.8%) when compared to group B (32.2%) and C (40.0%). On the other hand, the multiple pregnancy rate was significantly lower in group C (14.3%) when compared to group A (71.4%) and B (36.8%). Conclusion: The pregnancy rate was significantly decreased over 35 years. The G-sac/HQE and multiple pregnancy rate were significantly high below 31 years. Thus, these results suggest that the number of high quality embryo transferred should be limited by the age and another criteria for embryo quality evaluation were required for single embryo transfer.

• The Korean Journal of Zoology
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• v.27 no.1
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• pp.13-24
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• 1984

The fertilized eggs of Rana dybowskii were irradiated with UV (254 nm wave length) on the vegetal hemisphere to investigate the effects on the primordial germ cells (PGCs) and axis formation. The investigations were carried out in two ways; namely time course and UV dose. Up to 1,600 $ergs/mm^2$ of UV dose, irradiated at 60 min. after fertilization, there was no effect on the PGC number. However, the number of PGC comparing with that of unirradiated control was decreased more than 40%. As the amount of irradiation was increased, the number of PGC was inversely declined. The maximal dose of irradiation which eliminates PGC completely without inducing any axis abnormality was 4,800 $ergs/mm^2$. If the eggs were irradiated earlier with this amount the severer effect could be obtained. Thus the UV effect on the PGC number was most effective when irradiated by 60 min. post fertilization. Thereasfter stage. At UV doses over 9,600 $erge/mm^2$ other effects start to appear; namely abnormalities of nerual tube and axis formation. Therefore, comparative study on the UV sensitivity of PGC and axis formation was carried out. It was revealed that UV effect on the axis was drastically decreased at the time of $0.7\\sim0.8$ between fertilization and 1st cleavage, while the germ plasm was sensitive to UV until 4 cell stage.

• Korean Journal of Soil Science and Fertilizer
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• v.31 no.4
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• pp.384-391
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• 1998

Nutrient removal during stem harvest was evaluated in a one-year rotation willow bioenergy plantation. For the stem nutrient content, the stem biomass and stem nutrient concentration were collected in the winter of 1987-1993 from the established willow plantation at Tully, New York, U.S.A. in 1987. Five willow clones and one hybrid poplar clone were planted. Half of the plots were fertilized annually with $336kg\;ha^{-1}$ N, $112kg\;ha^{-1}$ P, and $224kg\;ha^{-1}$ K. All trees were harvested annually. Mean annual nutrient removals of N, P, K, Ca, and Mg by annual stem harvesting over seven years were respectively 30-70, 4-10, 14-40, 19-59 and $3-5kg\;ha^{-1}$. Fertilized plants exported higher quantities of nutrients than non-fertilized ones. Nontheless, quantities of nutrients exported were well below the quantities supplied by fertilization suggesting that nutrients removal by stem harvesting is not likely to cause a decrease in soil fertility. However, in non-fertilized plots, the amount of nutrients removed could result in decrease of nutrient availability and soil fertility over the long-term. An evaluation of the clones revealed that clone SV1 is the most nutrient efficient.

• Journal of Climate Change Research
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• v.8 no.4
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• pp.305-312
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• 2017

We aimed at investigating the difference in $N_2O$ emission factors of chemical and organic fertilizers and identifying the main factors influencing annual fluctuations in $N_2O$ emission. We conducted two-year experiments in 2016 and 2017 in an agricultural field planted with sweet potato (Ipomoea batatas). Treatments included chemical NPK fertilizer (NPK) and chicken compost application at $10\;ton\;ha^{-1}$, $20\;ton\;ha^{-1}$, and $30\;ton\;ha^{-1}$ rates (CK1, CK2 and CK3). Control was also employed with no addition. Results showed that $N_2O$ emission rates were significantly related with soil water status and soil available N contents. Significant correlation between % water filled pore space (WFPS) and $N_2O$ emission was observed only when the %WFPS was greater than 40% and during the initial stage of the experiment (<60 d). Comparison of the emission factors in 2016 and 2017 showed us that the emission factor was greater in 2016 when the %WFPS was maintained higher by 16.5% compared to that in 2017. In 2016, the emission factor of organic fertilizer was higher than that of chemical fertilizer, while in 2017, the pattern was reversed. Annual variability in $N_2O$ emission could also be originated from the available N contents remaining in soil after being taken up by plants. If we apply excessive N fertilizer, the soil would contain excess amount of N which was not uptaken by plants, leading to a huge increase in $N_2O$ emission. This case would overestimate emission factor, which was the case for the organic fertilizer in 2016. Over-fertilization should be avoided when we set up an experiment to determine $N_2O$ emission factor.

• Journal of Environmental Science International
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• v.32 no.4
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• pp.233-242
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• 2023

The objective of this study was to develop a management strategy for the recovery of carbon storage capacity of abandoned coal mine forest rehabilitation area. For the purpose, the biomass and stand carbon storage over time after the forest rehabilitation by tree type for Betula platyphylla, Pinus densiflora, and Alnus hirsuta trees which are major tree species widely planted for the forest rehabilitation in the abandoned coal mine were calculated, and compared them with general forest. The carbon storage in abandoned coal mine forest rehabilitation areas was lower than that in general forests, and based on tree species, Pinus densiflora stored 48.9%, Alnus hirsuta 41.1%, and Betula platyphylla 27.0%. This low carbon storage is thought to be caused by poor growth because soil chemical properties, such as low TOC and total nitrogen content, in the soil of abandoned coal mine forest rehabilitation areas, were adverse to vegetation growth compared to those in general forests. DBH, stand biomass, and stand carbon storage tended to increase after forest rehabilitation over time, whereas stand density decreased. Stand' biomass and carbon storage increased as DBH and stand density increased, but there was a negative correlation between stand density and DBH. Therefore, after forest rehabilitation, growth status should be monitored, an appropriate growth space for trees should be maintained by thinning and pruning, and the soil chemical properties such as fertilization must be managed. It is expected that the carbon storage capacity the forest rehabilitation area could be restored to a level similar to that of general forests.

• Korean Journal of Animal Reproduction
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• v.26 no.1
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• pp.1-7
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• 2002

The present study was carried out to investigate the effects of maturation media on penetrability of pig oocytes by liquid boar sperm coincubated with different sperm concentrations in a modified Tris­buffered medium (mTBM). Follicular oocytes collected from ovaries of prepubertal gilts were matured in a modified TCM-199 (mTCM-199) medium, modified Waymouth MB 752/1 (mWaymouth MB 752/1) medium or NCSU-23 medium. Oocytes (30~40) were transferred into each well of a Nunc 4-well multidish containing 0.5 $m\ell$ maturation medium. The sperm­ich portion of ejaculates with greater than 90% motile sperm were used in the experiment. The semen was cooled 22 to 24$^{\circ}C$ over 2 h period. The semen was diluted with Beltsville Thawing Solution (BTS) extender at room temperature to give 2$\times$10$^{8}$ sperm/$m\ell$ in 100 $m\ell$ plastic bottle. Liquid boar semen of 30 $m\ell$ in 100 $m\ell$ plastic bottle was kept at 17$^{\circ}C$ far 5 days. The sperm with greater than 70% motility after day 5 of storage were used for in-vitro fertilization (IVF). After 44 h maturation of immature oocytes in 5% $CO_2$in air at 38.5$^{\circ}C$, cumulus cells were removed and oocytes (30~40) were coincubated for 6 h in 0.5 $m\ell$ mTBM fertilization medium with five different (1$\times$10$^{6}$ , 2$\times$10$^{6}$ , 4$\times$10$^{6}$ , 6$\times$10$^{6}$, 10$\times$10$^{6}$ $m\ell$) sperm concentrations. At 6 h after IVF, oocytes were transferred into 0.5 $m\ell$ NCSU-23 culture medium fur further culture of 6 h. At 12 h after IVF, sperm penetration, polyspermy and male pronuclear formation of oocytes were evaluated. Oocytes of NCSU-23 maturation medium decreased polyspermy and increased male pronuclear formation compared to those of mTCM­199 and mWaymouth MB 752/1 maturation media. Of oocytes matured in NCSU-23 medium and inseminated in mTBM medium with 2~4$\times$10$^{6}$ $m\ell$ sperm concentrations, 50.8~50.9% showed sperm penetration, 13.3~19.5% polyspermy and 43.9~45.4% male pronuclear formation. In conclusion, we found out that oocytes matured in NCSU­23 medium and inseminated in mTBM medium showed superior in­vitro fertilization compared to those matured in mTCM­199 and mWaymouth MB 752/1 maturation media and inseminated in mTBM medium. The optimum sperm concentrations for in-vitro fertilization of oocytes matured in NCSU-23 medium by liquid boar semen stored at 17$^{\circ}C$ for 5 days were 2~4$\times$10$^{6}$ $m\ell$.

• Journal of Life Science
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• v.19 no.1
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• pp.123-128
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• 2009

Production of highly valuable immunotherapeutic proteins such as monoclonal antibodies and vaccines using plant biotechnology and genetic engineering has been studied as a popular research field. Plant expression system for mass production of such useful recombinant therapeutic proteins has several advantages over other existing expression systems with economical and safety issues. Immunotherapy of multiple monoclonal antibodies, which can recognize multiple targeting including specific proteins and their glycans highly expressed on the surface of cancer cells, can be an efficient treatment compared to a single targeting immunotherapy using a single antibody. In this study, we have established plant production system to express two different targeting monoclonal antibodies in a single transgenic plant through crossing fertilization between two different transgenic plants expressing anti-colorectal cancer mAbCO17-1A and anti-breast cancer mAbBR55, respectively. The F1 seedlings were obtained cross fertilization between the two transgenic parental plants. The presence, transcription, and protein expression of heavy chain (HC) and light chain (LC) genes of both mAbs in the seedlings were investigated by PCR, RT-PCR, and immunoblot analyses, respectively. Among all the seedlings, some seedlings did not carry or transcribe the HC and LC genes of both mAbs. Thus, the seedlings with presence and transcription of HC and LC genes of both mAbs were selected, and the selected seedlings were confirmed to have relatively stronger density of HC and LC protein bands compared to the transgenic plant expressing only each mAb. These results indicate that the F1 seedling plant with carrying both mAb genes was established. Taken together, plant crossing fertilization can be applied to generate an efficient production system expressing multiple monoclonal antibodies for immunotherapy in a single plant.