• Korean Journal of Animal Reproduction
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• v.23 no.4
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• pp.347-352
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• 1999

This cDNAs were cloned with the aid of the polymerase chain reaction (PCR) by sequences based on cloned rat LH/CG and FSH receptor cDNAs. A cDNAs of LHR and FSHR were transfected into the 293 cells. Several clonal cell lines were obtained expressing different numbers of cell surface receptors. One cell lines for each LHR and FSHR were chosen, and a corresponding cell lines expressing the wild type LHR and FSHR were selected based on the number of cell surface receptor for the particular LHR and FSHR. The abilities of the LHR and FSHR to transduce the hCG and FSH signals were measured by quantitating cAMP accumulation in cells incubated with increasing concentrations of hCG and FSH. The cAMP accumulation effects for these receptors were increased by the increasing concentrations of hCG and FSH. Thus, most of the receptors expressed in cells transfected with LHR and FSHR could be detected by measuring hormone binding and cAMP response, and can utilize to study the structure function and signal transduction of the choriogonadotropins and glycoprotein hormones.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.39 no.4
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• pp.307-316
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• 1994

To investigate the effect of light pretreatment on photosynthetic characteristics of leaf blade of rice, 2 varieties of japonica type and 2 varieties of tongil type were grown under 30% or 70% shading conditions from tillering stage to heading stage. Shading treatment of 70% at the heading stage produced low dry matter, and higher LAR and SLA compared with other combination of shading treatment and growing stage did. Photosynthetic activity was lower in order of 0%, 30% and 70% shading treatment under the low light intensity(5Klux) but significantly high in 30% shading treatment under the high light intensity (33Klux) at tillering stage. Photosynthetic activity under low(5Klux) and high(33Kluk) light intensity were higher in order of 70%, 30% and 0% shading treatment at heading stage. Respiration /photosynthesis ratio was lower in shading treatment than in control. CGR, RGR and NAR decreased in shading treatment. Shading treatment reduced the number of ripened grain per panicle and decreased the harvesting index.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.26 no.3
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• pp.257-262
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• 1981

Field experiment with 0, 100, 200, 400, and 800 kg-N/ha-year application levels was carried out to study the nitrogen response in the early stage of orchardgrass pasture establishment at College Fann, SNU, in 1979 and 1980. Both the highest dry matter yield and maximum percent of N recovery were obtained at the same level of 200 kg-N/ha in the year of seeding. but those of the next year were obtained at 400 kg-N/ha level. Leaf area indices (LAI) and net assimilation rates (NAR) during each regrowth periods as well as total nitrogen contents of forage at each cutting time increased with applied N in both years. The maximum crop growth rate (CGR) over two years was estimated to be obtained when LAI reached to about 5. The accumulation of NO_3 -N in forage started from 400kgㆍN/ha application in 1980. and exceeded the safe level for ruminants at the level of 800 kg-N/ha.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.4
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• pp.269-272
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• 2002

This study was carried out to investigate varietal differences on growth characteristics under the conditions of PE film-mulching and non-mulching in sesame. At maturing stage from 76 to 95 days after sowing, Yangbaeckkae, non-branching plant type, under non-mulching showed larger leaf area index (LAI) than that of film-mulching, while plant height and the number of capsules per plant were similar to those of film-mulching. LAI of Ahnsankkae, branching plant type, under non-mulching was similar to film-mulching, while plant height and the number of capsules per plant were smaller than those of film-mulching. Net assimilation rate (NAR) of two varieties under non-mulching was lower at seedling stage from 25 to 35 days after sowing but higher at flowering stage from 45 to 55 days after sowing. At maturing stage from 66 to 77 days after sowing, NAR and crop growth rate (CGR) of Yangbaeckkae under non-mulching were greater than those of film-mulching, whereas those of Ahnsankkae under non-mulching were lesser than those of film-mulching. Yield under non-mulching was decreased by 7 % in Yangbaeckkae and 33 % in Ahnsankkae compared with that of film-mulching, therefore Yangbaeckkae was more adaptable for non-mulching than Ahnsankkae. Main factors decreasing yield of Yangbaeckkae under non-mulching were small LAI, NAR, and CGR at the stage of young seedling, and small number of capsules at early maturing stage from first flowering to 20 days after first flowering.

• The Korean Journal of Ecology
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• v.3 no.1_2
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• pp.11-16
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• 1980

Growth analytical and primary productivity experiments of soybean populations were conducted with special references to the development of productive structures and environmental conditions of nitrogen levels $(N_1,\; control:\; N_2,\; 6.67gN/\textrm m^2:\; N_3,\;13.34\textrm {gN/m}^2)$. The maximum amounts in LAI for $N_1,\; N_2\; and\; N_3$ stand were 17.3, 19.0 and 18.5; in total standing grops, 1570, 1785 and 1704gDM/$\m^2$; in total net productions, 543, 648 and 636gDM/$\m^2$, respectively. The maximum CGR attanined were 208, 237 and 272 gDM$\m^2$/week, while the mean EU was 2.55, 2.92 and 2.84% N1, N2 and N3, respectively. The total nitrogen standing quantity attained 53.4, 71.8 and 59.8 gN/$\m^2$ at the maximum standing crop period. The net nitrogen absorption rates showed highly significant differences among nitrogen treatments, i.e., 1.34, 10.77 and 13.22 mg/g/day for $N_1,\; N_2\; and \;N_3$ stand, repsectively.

• Korean Journal of Plant Resources
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• v.11 no.1
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• pp.80-85
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• 1998

The influence of elevated CO2 and temperature on growth parameters, biomass production and its partitioning of rice (Oryza sativa L.cv. Chukwangbyeo) were investigated in the three experiments (1991-1993). Rice plants were grown from transplanting to harvest at either ambient(350ppm) or elevated CO2 concentrations (690 or 650ppm) in combination with either four or seven temperature regimes ranging form ambient temperature (AT) to AT plus 3$^{\circ}C$.From transplanting to panicle initiation, crop growth rate (CGR) was enhanced by up to 27% with elevated CO2 , primarily due to an an increase in leaf area index. although net assimilatiion rate was also greater at elevated CO2. The effect of elevated CO2 varied with temperature. During the reproductive phase, CGR declined linearly with increased temperature, and was greater at elevated CO2 . Elevated CO2 increased final crop biomass and panicle weight 30% respectively at AT(27.6$^{\circ}C$ : 1991) . However, there was no significant effect of elevated CO2 on panicle weight at AT plus 3$^{\circ}C$, where severe spikelet sterility occurred. There was no significant effect of elevated CO2 on panicle weight at AT plus 3$^{\circ}C$, where severe spikelet sterility occurred. There was also no effect of CO2 on biomass pratitioning into vegetative and reproductive organs (harvest index)) at AT, although higher temperature could affect that by inducing spikelet sterility. These results suggest that elevated CO2 could enhance rice producivity througth promoted growth and biomass production , but its positive effects may be less at higher temperatures.

• Development and Reproduction
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• v.25 no.4
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• pp.199-211
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• 2021

Equine chorionic gonadotropin (eCG), produced by the endometrial cups of the placenta after the first trimester, is a specific glycoprotein that displays dual luteinizing hormone (LH)-like and follicle-stimulating hormone (FSH)-like effects in non-equid species. However, in equidaes, eCG exhibits only LH-like activity. To identify the specific biological functions of glycosylated sites in eCG, we constructed the following site mutants of N- and O-linked glycosylation: eCGβ/αΔ56, substitution of α-subunit⁵⁶ N-linked glycosylation site; eCGβ-D/α, deletion of the O-linked glycosylation sites at the β-subunit, and eCGβ-D/αΔ56, double mutant. We produced recombinant eCG (rec-eCG) proteins in Chinese hamster ovary suspension (CHO-S) cells. We examined the biological activity of rec-eCG proteins in CHO-K1 cells expressing the eLH/CG receptor and found that signal transduction activities of deglycosylated mutants remarkably decreased. The EC₅₀ levels of eCGβ/αΔ56, eCGβ-D/α, and eCGβ-D/αΔ56 mutants decreased by 2.1-, 5.6-, and 3.4-fold, respectively, compared to that of wild-type eCG. The Rmax values of the mutants were 56%-80% those of wild-type eCG (141.9 nmol/10⁴ cells). Our results indicate that the biological activity of eCG is greatly affected by the removal of N- and O-linked glycosylation sites in cells expressing eLH/CGR. These results provide important information on rec-eCG in the regulation of specific glycosylation sites and improve our understanding of the specific biological activity of rec-eCG glycosylation sites in equidaes.

• Journal of Practical Agriculture & Fisheries Research
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• v.20 no.1
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• pp.175-185
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• 2018

This study was conducted to evaluate the physiological and ecological characters of rice cultivars suitable for low fertilized condition. 5 rice cultivars(Jinmibyeo, Sobibyeo, Hwayeongbyeo, Nagdongbyeo and Junambyeo) were cultivated for selection under 3 different nitrogen application levels, and 1 cultivars were selected. The results obtained are summarized as follows ; High yielded rice cultivars under low N application level were Junambyeo, Jinheng and Sobibyeo. Also these cultivars were yielded highly under conventional level(11kg/10a). Milled rice yield under conventional level(11kg/10a) was positively correlated with them under low N levels. Milled rice yield was most affected by no. of grain/m². Rice cultivars that were high crop growth rate(CGR) before heading stage were Junambyeo, Sobibyeo and Nagdongbyeo. Grain filling rate was increased mostly until 20 days after heading, and decreased after this stage. Nitrogen use efficiency was higher under low N level(5.5kg/10a) than conventional level(11kg/10a). Especially, Junambyeo was most low in Apparent recovery of applied N(AR) under low N application level, but most high in Agronomic N use efficiency(ANUE). This characteristics of Junambyeo will to be useful for selection of variety suitable for growing under low fertilized condition.

• Asian Journal of Turfgrass Science
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• v.15 no.2
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• pp.65-76
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• 2001

This study was designed to estimate on the interaction of the first productivity, light condition and to examine the ecophysiological characteristics of Zoysia japonica. rtificial community of Zoysia japonica was analyzed effect of matter production and growth construction under various shading condition. The results summarized this experiment were as follows; 1. The relative growth rate (RGR) in all experimental plots was high during the growth stage of 20 days after transplanting, and then decreased. The maxium RGR value appeared in the control plot (2.13g/g. 10days) during the growth stage from 10 to 20 days after transplating. RGR value in server shading of short day condition was remarkably decreased from the early growth stage. The main factor to lower RGR value considered as a short day condition than that of shading. 2. The net assimilation rate (NAR) in all experimental plots except 3hour photoperiod plot was high during the early growth stage after transplanting, and then decreased early growth stage after transplanting, and then decreased as the growth proceeded. The maxium value appeared in the control plot (35g/g. 10days). NAR value in the severe shading of short day condition plots was low. Especially, NAR value in the three hours photoperiod plot was remarkably low from the early growth, there was no great difference by growth stage. NAR had negative correlation with LAI and positive correlation with RGR. 3. The increasing rate of leaf area ratio(LAR) was high during the early growth stage after transplanting in the control plot and in the photoperiod plot, the shorter the exposure time to sunlight, the higher the LAR value from the early growth stage. Especially, its value in the 3 hour photoperiod plot was remarkably high but its increasing rate was lower as the growth proceeded. LAR hade negative correlation on RGR and NAR. 4. The crop growth rate(CGR) in each experimental plot was increased until 50 days after transplanting, and then decreased. After that time, the maxium CGR value appeared in the control plot (1.56g/$\textrm{cm}^2$. 10-days), 60 days after transplanting, CGR had positive correlation with LAI. The optimum LAI in the control, 9 hour, 7 hour, 5 hour, and 3 hour photoperiod plots appeared as 1.87, 1.12, 0.83, and 0.18.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.51 no.7
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• pp.599-607
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• 2006

The experiments were carried out to develop simulation model for estimating the yield of soybean in upland and paddy field condition. Field experiments were done at National Institute of Crop Science in 2005. The evaluated soybean cultivars were Taekwangkong, Daewonkong, and Hwangkeumkong. Soybean seeds were planted by hill seeding with 3-4 seeds and row and hill spacing were $60{\times}10cm$ in upland and $60{\times}15cm$ in paddy field. Seeds were sown on row (without making ridge) and on the top of ridge in upland and paddy field, respectively. Field parameters were measured yield components ($plants/m^{2}$, pod no./plant, and 100-seed weight, seed yield and growth characteristics (stem length, leaf area at each stage, and dry weight of shoot) and after measuring they were compared the relationships with seed yield and yield components and seed yield and growth characteristics. Seed yield of soybean was affected by cultivars and planting density. Seed yield was higher in upland than paddy field due to the higher planting density in upland field. The upland soybeans generally had lower 100-seed weight than that of paddy field. Seed yield of soybean in a paddy field was greatest in Taekwangkong and followed by Daewonkong and Hwangkeumkong. The harvest index of taekwangkong and Hwanggumkong was higher in upland than paddy field, however, it was higher in paddy field than upland in Daewonkong. Seed yield was greatest in Daewonkong in both experimental fields. The greatest stem length was observed in taekwangkong and Hwanggumkong (R6) in late growth stage in paddy field. Dry weight of shoot and pod, pod number, stem length, and stem diameter were higher grown in paddy field than grown in upland. Crop growth rate (CGR) of cultivars was higher in paddy field after 8 WAS(weeks after sowing) and it was greatest at 13 WAS in Daewonkong among the cultivars. In upland field, CGR was greatest in Taekwangkong and then followed by Daewonkong and Hwanggumkong during 12 and 15 WAS. There was no significant relationships between 100-seed weight and seed yield in both experimental fields. A significant positive relationship was observed between seed number and seed yield. The correlation coefficients between leaf area and shoot dry weight were about 0.8 during the whole growth stage except 5 WAS and 4-5 WAS in paddy field and upland, respectively. This experiment was done just one year and drained paddy field condition was not satisfied drained condition successfully at 7th leaf age of soybean by the heavy rain, so we suggest that the excessive soil water reduced seed yield in paddy field and the weather condition should be considered for utilizing of these results.