• KOREAN JOURNAL OF CROP SCIENCE
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• v.47 no.3
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• pp.174-185
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• 2002

This study was carried out to investigate the effects or abscisic acid (ABA), three concentrations, on growth, activities of antioxidant-related enzymes and grain yield of two rice plants (Oryza sativa L. cv. Hwamyungbyeo and cv. Namchunbyeo) exposed to ozone (0.150 ppm) for 6 hours a day for 30 days. The leaf chlorop0hyll contents, plant height, and tillering numbers were not shown significant difference. But ABA 10$^{-5}$ M treatment affects to growth slightly. In all concentrations of ABA, superoxide dismutase (SOB) activities were increased at tillering stage of Namchunbyeo which was exposed to ozone. It is considered that the optimum concentration of ABA is 10$^{-5}$ M for minimizing loss of grain yield loss.

• Food Science and Preservation
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• v.12 no.1
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• pp.1-7
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• 2005

The effect of packing methods on the green powder tea were investigated by examining quality changes during cold stroage. Packing was performed with aluminum packs having an antioxidant and a wateiproofing agent in vacuum Alumiunum packing with treatment or not showed little changes till 2 months but after this period remarkable quality degradation were found in total nitrogen, total amino acids, tannin, caffeine, chlorophyll and fatty acids. The color changes of gieeness were -16.43 in one month and -10.11 in five months, respectively. Alumininum packing in vacuum was showed extention of storage period above one month.

• Food Science and Preservation
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• v.13 no.6
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• pp.681-685
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• 2006

The effect of storage methods on green tea powder were investigated by examining quality changes of the tea during storage at $-5^{\circ}C$. aluminium-packing without any treatment showed the green powder tea quality of unchanged for 120 days storage, after which significant decrease in the green powder tea constituents connected quality such as total nitrogen, total amino acid, tannin, caffeine, chlorophyll, vitamin C, and fatty acid were observed. The changes in the green color indexes(a value) of green powder tea at $-5^{\circ}C$ were resulted in the of -16.69, -16.20, and 13.69 for 30, 60, and 120 days with the storage period respectively. A sensuous examination for quality assay of the green powder tea demonstrated 93, 91, 88 and 73 points as a storage period 0, 30, 60 and 120 day, respectively. This study suggested that storage method at $-5^{\circ}C$ was a successful method for storage of green powder tea.

• Proceedings of the Plant Resources Society of Korea Conference
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• 2019.10a
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• pp.61-61
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• 2019

본 연구에서는 실내 광조건에서 자생 장미과 상록 활엽 목본 2종의 생육반응을 조사하였다. 식물재료는 다정큼나무[Rhaphiolepis indica var. umbellata (Thunb.) Ohashi]와 비파나무[Eriobotrya japonica (Thunb.) Lindl.]의 3년생 실생묘를 사용하였다. 실내 광량은 10, 50, 100 및 200 PPFD (${\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$)로 설정되었으며, 광주기(12/12 h), 온도($25{\pm}1^{\circ}C$), 습도($55{\pm}3%$) 및 관수(1회/3일) 주기는 일정하게 유지하였다. 실내에서 8주간 재배한 다음 유리온실에서 동일 기간동안 재배된 대조구와 생육 및 광합성 능력 등을 비교하였다. 연구 결과, 다정큼나무의 생육은 200 PPFD에서 대조구와 유사한 수준이었으며, 줄기직경은 광량과 정비례하는 경향이었다. 엽수는 대조구에 비해 고 광량(100, 200 PPFD) 조건에서 유의적으로 높은 결과를 보였다. 처리 별 최대 양자수율(Fv/Fm) 및 광계II 성능지수(Pi_Abs)는 대조구와 유사한 수준이었으며, 광량에 따른 유의적인 차이가 없었다. 비파나무는 재배기간 동안 광량에 관계없이 생육변화가 크지 않았으나, 엽록소함량은 200 PPFD에서 가장 많았다. 한편 10 PPFD에서는 모든 개체의 잎 고사에 따른 관상가치가 하락하였다. Fv/Fm은 200 PPFD에서 대조구와 유사한 수준이었으며, Pi_Abs는 저광량(10, 50 PPFD) 조건에서 유의적으로 높은 수치였다.

• Journal of Korean Society of Forest Science
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• v.106 no.1
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• pp.40-53
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• 2017

The purpose of this study was to evaluate the effects of container types on physiological characteristics of Zelkova serrata, Fraxinus rhynchophylla and Quercus serrata in the container nursery stage. We used 16 container types [4 growing densities (100, 144, 196 and $256\;seedlings/m^2$)${\times}4$ cavity volumes (460, 380, 300 and $220cm^3/cavity$)] and performed two-way ANOVA to test the differences in photosynthesis, photochemical efficiency and chlorophyll content among container types. Also, multiple regression analysis was conducted to correlate container dimensions with photosynthetic rate. Container types had a strong influence on photosynthesis of three species seedlings. Growing densities and cavity volumes had a significant interaction effect on photosynthetic rate, water use efficiency, stomatal conductance and chlorophyll contents except stomatal conductance of Q. serrata. In all three species, however, interactions between the two factors of container type were not found with regard to photochemical efficiency. Growing density was negatively correlated with photosynthetic rate of F rhynchophylla and Q. serrata, while cavity volumes positively affected on those of three species seedlings. The range of optimal container types was determined by multiple regression analysis based on photosynthetic rate. Consequently, optimal growing density and cavity volume of container by each tree species were found to be approximately $160{\sim}210\;seedlings/m^2$ and $430{\sim}460cm^3/cavity$ for Z. serrata, $130{\sim}150\;seedlings/m^2$ and $390{\sim}440cm^3/cavity$ for F. rhynchophylla and $130{\sim}170\;seedlings/m2$ and $420{\sim}460cm^3/cavity$ for Q. serrata, respectively. Application of adequate container will induce higher quality seedling production in nursery stage, which will also increase seedling growth in plantation stage.

• Korean Journal of Environmental Biology
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• v.26 no.4
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• pp.271-278
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• 2008

The differences of several kinds of physiological responses between Commelina communis (C$_3$ plant) and Sedum sarmentosum (CAM plant: Crassulacean Acid metabolism) when both plants were exposed to water stress for 3 weeks were investigated. In case of Commelina it was shown a clear loss of water to 12% in three weeks, but no changes were observed in Sedum. Total chlorophyll content was also reduced to 57% in Commelina but not clear changes of chlorophyll content in Sedum. were observed for three weeks. In chlorophyll fluorescence experiments Fv/Fm ratios were reduced to 19% in Commelina, but no changes were observed in Sedum. There were very sensitive responses according to the different KCl concentrations and the stomatal aperture of epidermal strips was 12.8 ${\mu}m$ at 200 mM KCl in Commelina, but less than 3 ${\mu}m$ was observed at the same KCl concentration in Sedum. In addition, there were no chloroplasts in guard cells of Sedum, but most plants had chloroplasts including Commelina. From the above results, the ability of water stress resistance in Sedum. could be come from slow physiological metabolism including growth and less loss of water through unique stomatal characteristics.

• Horticultural Science & Technology
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• v.30 no.4
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• pp.392-399
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• 2012

This study was carried out to investigate the influence of molybden (Mo) concentrations in fertilizer solution on the growth of and nutrient uptake by domestically bred strawberries. Tissue analysis based on the dry weight was also conducted to determine the threshold levels in plants when Mo toxicity developed in strawberries. The leaf chlorophyll contents decreased lineally as Mo concentrations in the fertilizer solution were elevated. The differences among treatments in chlorophyll contents were statistically significant. The fresh and dry weights decreased significantly when the Mo concentrations in fertilizer solution were higher than 3.0 mM in 'Keumhyang' and 'Maehyang' strawberries and 1.0 mM in 'Seolhyang' strawberry. The elevation of Mo concentrations in fertilizer solution resulted in severe toxicity and crops developed the unique symptoms. The margin of older leaves became yellow and desiccated. Then, the margin of leaf blade rapidly became bronze colored and died as the symptoms spread up the plants. The interveinal area of the young leaves became yellowing. The elevation of Mo concentrations in fertilizer solution did not influence the tissue P, K, and Mg contents based on the dry weight. The tissue Ca contents were higher in 1.0 mM treatment than other treatments of 'Keumhyang' and 'Seolhyang' strawberries. The tissue Mo contents based on the dry weight of 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries were 76.5, 104.0, and 187.3 $mg{\cdot}kg^{-1}$, respectively, in the 0.25 mM treatments and 4,155, 5,367, and 2,190 $mg{\cdot}kg^{-1}$, respectively, in the 4.0 mM treatments. The contents increased lineally as Mo concentrations in fertilizer solution were elevated. When the concentration of Mo at which growth of crops were retarded by 10% is regarded as threshold level, the Mo contents based on dry weight of above ground plant tissue should be lower than 653.4, 686.2, and 589.7 $mg{\cdot}kg^{-1}$, in 'Keumhyang', 'Maehyang', and 'Seolyahng' strawberries, respectively.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.37 no.2
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• pp.123-133
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• 1992

This study was conducted to clarify progressed changes of plant types and the effects of the physiological and ecological components on improving ideotype of winter wheat. 12 wheat varieties were planted at the experimental farm of Wheat and Barley Research Institute in Suwon in 1990. As results of intensive wheat breeding for early maturity since 1959, heading, flowering and maturing dates have been shortened by 17, 15 and 14 dagys, respectively. The shortened days from sowing to heading and from heading to flowering contributed to the early maturity to improved. Physiological factors associated with heading time of wheat could be reprsented by growth habit, photoperiod responses, earliness in narrow sense and winter hardiness. For improving an early maturity of winter wheat, it would desired to maintain some degree of winter habit(III-IV), and recombination of more insensitivity to short day length and more shortened earliness in narrow sense than that of Saemil and Chugoku 81, and higher degree of winter hardiness. For improving the early maturity the more effective way must be of shortened days from sowing to heading, and days from flowering to maturity than days from heading to flowering. Ideotype of wheat will be desired to recombine two semi-dwarf genes with erect plant type being about 70-80cm, less stem elongation by late spring, long spike and many grains per spikelet. Average spike weight ratio was about 45-49% in high-yielding varieties, stem fresh weight was lighter, but spike fresh weight was heavier in new one while leaf fresh weight was similar to each other during the maturing periods. Average spike dry weight ratio was higher about 40～48%, and stem and leaf blade dry weights were lower in the newly bred varieties. Stem dry weight was heavier than spike or leaf dry weight in the old varieties of Yungkwang, Jangwang and Jinkwang. Leaf area index for the varieties showed normal distribution curve as the maximum point in booting stage. The maximum point of this curve come in early maturing wheat, and late in old one. The maximum points of LAI were 6.4～6.8 in the high-yielding varieties. Totals of LAI in each period investigated of old one were higher than those of newly bred being 24.6～28.8. Chlorophyll content of the high-yielding varieties of Chokwang, Geurumil and Saemil as higher than that of the old varieties Jangkwang, Jinkwang, Wonkwang and Sinkwang from regrowing period to April 21. after then slightly and even after heading. Net assimilation rate (NAR) was higher in high-yielding varieties with good plant type, and lower in old ones. Grain yield of the newly released varieties increased rapidly but slowly in the old ones. Change in water content of grain at the growing stage in newly bred was lower than that of the old bred. Diminishing rate of water content of grain in establishment per day was 1.2% average that of the old varieties including Yungkwang was 1.5%, and those of the newly bred including Chokwang were 0.9～1.1%. Chokwang, Naemil, and Saemil were the highest-yielding varieties of the Korean cultivars. Yields were increased by spikes per m$^2$, grain weight for the varieties bred in Suwon, and by spikes per m$^2$ for the varieties bred in Milyang.

• Journal of Bio-Environment Control
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• v.30 no.1
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• pp.77-84
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• 2021

This study attempted to find a way to maintain the quality of mixing baby wild leaf vegetables with existing baby leaf vegetables in various ratios. The crops for mixing baby leaf vegetables were Peucedanum japoincum Thunberg and Ligularia stenocephala, as wild vegetables, and red romaine, which is widely used in young leafy vegetables. The mixing ratio of red romaine and wild vegetables was red romaine 0: mantilla oil 5: L. stenocephala ratio 5 (R0: P5: L5), red romaine 3.3: P. japoincum 3.3: L. stenocephala ratio 3.3 (R3.3: P3.3: L3.3), red romaine 5: P. japoincum 2.5: L. stenocephala 2.5 (R5: P2.5: L2.5), red romaine 8: P. japoincum 1: L. stenocephala 1 (R8: P1: L1), red romaine 10: P. japoincum 0: L. stenocephala 0 (R10: P0: L0). All treatments were packaged in OTR (oxygen transmittance) 10,000 cc m-2·day-1·atm-1 film and stored for 27 days at 2℃/85% RH conditions. Fresh weight, carbon dioxide, oxygen, and ethylene concentrations of the baby leaf packages were examined approximately every 3 days, and visual quality, chlorophyll content, and chromaticity were examined on the 27th day of storage. The oxygen and carbon dioxide concentration in the packages were affected by the respiration rate of the crop. As the mixing ratio of lettuce, which had a low respiration rate, increased, the oxygen concentration in the packages was higher and the carbon dioxide concentration was lower. Oxygen concentration decreased significantly after 15 days, but was remained above 16%, and on the contrary, carbon dioxide concentration was kept at 1-4% until the 15th, and then gradually increased to 2-5% on the 27th day. The concentration of ethylene was maintained at 3-6 µL·L-1 until the end of storage (27th day). Visual quality score measured at the end of storage was slightly less than 3.0, which is the limit of marketability of all treatments. Although there was no significant difference, the chlorophyll content (SPAD) of red romaine and P. japoincum were most similar with an initial value in R8:P1:1 treatment, and L. stenocephala was higher value in R8:P1:L1 and R5:P2.5:L2.5 treatments at the end of storage. The leaf color (L∗, a∗, b∗, chroma) of the three crops at end of storage compared with the heat map showed the least change in the R5:P2.5:L2.5 and R8:P1:L1 treatments at the end of storage. Among them, R8:P1:L1 treatment maintained the highest chlorophyll content, the second lowest ethylene concentration, and adequate carbon dioxide concentration of 2-3%. Therefore, it is judged that the mixed ratio of red romaine 8: P. japoincum 1: L. stenocephala 1 (R8: P1: L1) is most suitable for the mixed package of baby leaf vegetables of these three crops.

• Horticultural Science & Technology
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• v.35 no.2
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• pp.188-198
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• 2017

Asparagus (Asparagus officinalis L.) spears were treated with white (color temperature 4,500 k), blue (peak 450 nm), and red (peak 660 nm) light-emitting diodes (LEDs) at a photosynthetic photon flux density (PPFD) of $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for 12 h, and UV-B (280 nm) at 0.5 kJ or 1.0 kJ to determine the effect on agronomic characteristics, antioxidant phytochemicals, and antioxidant activity. The fresh weight, length, and width of spears were not affected by light quality treatments. The free sugars and chlorophyll contents were increased by 9 and 41%, respectively in the UV-0.5 kJ treatments. Among the antioxidant phytochemicals (vitamin C, total phenol, rutin, and total flavonoid), vitamin C was most greatly affected by the light treatments. Vitamin C content was significantly increased in asparagus spears subjected to the white (114%), red (137%), and UV-0.5 kJ(127%) treatments compared to the control. By contrast, rutin, total phenol, and total flavonoid content were increased only in samples subjected to the red and UV-0.5 kJ treatment. Furthermore, antioxidant activity, as measured by DPPH (2,2-diphenyl-1-picrylhydrazyl) radical scavenging activity, increased in white, red, and UV-0.5 kJ treatments by about 43, 41, and 43%, respectively, compared to the control. These results suggest that postharvest treatment of asparagus spears with red light at $200{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ for 12 h or with UV-B (280 nm) at 0.5 kJ could enhance the functional quality of the asparagus spears by increasing the content of phytochemicals like vitamin C, rutin, total phenolics, and total flavonoids.