• 한국환경생태학회지
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• 제20권1호
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• pp.70-74
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• 2006

이 연구는 관상용이나 천연감미료, 생리활성물질의 원료로 활용되는 산수국의 적정 생육조건을 구명하고자 수행하였다. 2년생 산수국의 삽목묘를 대상으로 광, 수분 및 시비처리를 실시한 후 8월과 9월에 광합성, 엽록소 함량, 엽생장을 조사 비교하였다. 광도처리별 광합성율의 유의차는 8월에는 유의차가 인정되었으나, 9월에는 유의차가 인정되지 않았다. 관수처리별 광합성율은 주3회 관수처리구에서 높았다. 시비구가 무시비구에 비해 광합성율이 약간 높게 나타났다. 엽록소함량은 광도처리별에 있어서는 8,9월 모두에서 유의차가 인정되었으며, 관수처리별에서는 8월에서만 유의차가 나타났으며 시비처리에서는 모두 유의차가 인정되지 않았다. 엽생장(엽장과 엽폭)은 전광과 주 3회 관수처리 시에 양호하였다.

• Journal of Plant Biology
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• 제36권2호
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• pp.133-140
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• 1993

The photosynthetic activities in relation to oxygen evolution rates, quantum yield, CO2 uptake rates and room temperature chlorophyll fluorescence were investigated in cotyledons of cucumber seedlings exposed to low temperature (at 4$^{\circ}C$) for 24 h. Light-chilling caused more inhibition on light-saturated maximum oxygen evolution rates, quantum yield, and CO2 uptake rates than dark-chilling did in the cucumber plant. Light-chilling induced more marked increase in Fo and decrease in (Fv)m/Fm than dark-chilling did in the room temperature chlorophyll induction kinetics. The above results affected by chilling in the light are considered to be associated with the partial damage of the reaction center of PS II and the decreased photosynthetic activities. There occurred a large decrease in qQ with little change in qNP in the light-chilling plant. When light- and dark-chilled plants were recovered at room temperature for 24 h and their chlorophyll fluorescences were induced with light doubling technique, light-chilled plants showed more smaller magnitude and rate of fluorescence relaxation than dark-chilled plants. These suggest that light-chilling might cause some alterations in transthylakoid pH formation, and that photosynthetic apparatus of cucumber cotyledons is more susceptible to light-chilling. In the fast fluorescence induction kinetics, FR was decreased by 60% in the light-chilled plants with reference to $25^{\circ}C$ light-grown plants, while the dark-chilled plants showed a decreased rate of only 20% with reference to $25^{\circ}C$ dark-treated plants for 24 h, indicating that cucumber seedling is very sensitive to chilling stress. So, it is certain that chilling injury to the photosynthetic apparatus is strongly dependent on the presence of light in cucumber seedlings.

• 임산에너지
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• 제19권1호
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• pp.1-6
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• 2000

본 연구는 소나무(Pinus densifora S. et Z.) 유묘의 발아전 단계, 자엽 단게 및 1차엽 발생후 단계 등 각각의 생육단계에서의 UV-B 증가 환경에 노출될 때의 생장반응을 탐구하고자 16주 동안 3수준의 UV-B(ambient UV-BBE, ambient + 3.2, ambient + 5.2 KJm-2s-1) 조사량이 설치된 야외 포장에서 실시되었다. UV-B 조사에 의하여 소나무 유묘의 수고생장, 근원경생장 및 건물생산량은 감쇠되었으며 T/R율은 증가하였다. 유묘에 대한 UV-B 처리시작 단계 차이에 따른 생장차이도 관찰되었는데, ambient +3.2 처리구내에서 보면 발아전 단계부터 UV-B 처리를 받은 유묘의 수고생장 및 근원경생장이 상대적으로 높았다. 주 수준의 UV-B 증가 처리구에서 모두 자엽단계부터 처리를 잗은 유묘의 건물생산량이 각 처리구내에서 가장 낮앗다. 한편 UV-B 증가에 의해 소나무 유묘 침엽의 엽롭소 함량은 감소하였으며 엽록소 a/b율은 증가하였다.

• 한국양식학회지
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• 제10권4호
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• pp.457-462
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• 1997

1997년 9월 1일과 2일 심한 적조가 발생된 해역의 가두리 양식어장에서 적조원인 생물인 Cochlodinium polykrikoides의 주야 수직이동을 세포수와 Chlorophyll a로 분석한 결과 낮에는 표층에서 4 m까지 농밀층이 분포하고 있었으나 저녁에는 저층 10 m, 15 m층에 주로 분포하였다. 이로 볼 때 황토를 이용한 적조방제는 저녁 18시부터 20시까지, 아침 8시부터 10시까지가 눈에 보이지 않는 위험시기이다. 조사 당시 가두리 주위에 황토를 12시부터 18시까지 연속적으로 뿌려 적조를 방제하였으나 가두리 주위에서 용존산소의 분포는 정상이었다. 이때 수질환경 중 pH는 8.45로 정상치보다 높았으며 영양염 중 암모니아와 인산은 군집유지에 효율적으로 이용되었고, 질산염과 규산염은 정상보다 다소 높은 농도를 나타내었다.

• 한국농림기상학회지
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• 제10권4호
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• pp.141-148
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• 2008

피음처리에 의한 네 참나무 수종(신갈나무, 졸참나무, 상수리나무, 굴참나무)의 광합성 반응 특성을 조사하기 위하여, 차광막으로 전천광을 35%, 55%. 75% 차광 처리한 조건과 전광조건에서 엽생장과 엽록소함량을 측정하고 광-반응 곡선과 A-Ci 곡선을 통하여 광합성계의 특성을 조사하였다. 그 결과, 굴참나무와 상수리나무는 엽생장, 엽록소함량, 순양자수율을 증가시키고 엽록소 a/b와 탄소고정효율을 감소시켜 빛의 흡수량과 광합성에 대한 이용효율을 높이는 적응 반응을 나타냈다. 신갈나무는 굴참나무와 상수리나무와 같은 경향의 적응반응을 보였지만 광합성 광화학계 활성의 저하로 낮은 광합성 능력을 나타냈다. 졸참나무는 가장 낮은 내음성 적응반응을 나타냈다.

• 한국환경과학회지
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• 제11권10호
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• pp.1023-1030
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• 2002

The effects on photosynthesis of NaCl(0, 0.2, 0.4, 0.6, 0.8 or 1.0 M) were examined in etiolated barley seedlings. Chlorophyll(Chl) a, Chl b and carotenoid contents, Chl a fluorescence and quenching coefficients of Chl fluorescence have been determined in the primary leaves of etiolated barley seedlings cultivated under low light(60 $\mu$㏖ $m^{-2}\;s^{-1}$). Chl a, b, and carotenoid contents were decreased remarkably in comparison with the control at 0.4 M NaCl. However, the value of Fo and Fv were decreased at 0.6 M NaCl and the ratio of Fv/Fm were deceased at 1.0 M NaCl. Chlorophyll synthesis was seriously inhibited from 0.4 M NaCl, and the photosynthetic electron transport system was inhibited from 0.6 M NaCl. Quantum of photosystem II reaction center was inhibited at 1.0 M NaCl. The effects of NaCl on the Chl content were raised in a 6 hrs, but the effects of NaCl on the value of Fo, Fv and Fv/Fm were raised in 30 hrs. The value of qP was decreased in comparison with the control at all concentrations, but there was a small change in the value qE. These results provide evidence that NaCl inhibited effects of various concentration of NaCl were inhibited quinone redox, however, proton gradient between thylakoid membranes was little damaged.

• 한국환경과학회지
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• 제16권11호
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• pp.1313-1318
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• 2007

Illicium anisatum was bred under four different light intensity. Those condition were full sunlight(PPFD $1600{\mu} mol\;m^{-2}s^{-1}$), 30% treatment(PPFD $400{\mu} mol\;m^{-2}s^{-1}$), 50% treatment(PPFD $250{\mu} mol\;m^{-2}s^{-1}$) and 70% treatment(PPFD $100{\mu} mol\;m^{-2}s^{-1}$), respectively. Chlorophyll a and b were increased according to decrease of light intensity. Thirty percent and 50% treatment had not significant different in chlorophyll a and b. Thirty percent treatment was shown the best photosynthetic activity through invested photosynthetic rate, intercellular $CO_2$ concentration and water use efficiency. Photosynthetic activity trend of 50% treatment was similar to 30% treatment. Seventy percent treatment was shown the best photosynthetic activity at low light intensity but that was decreased to lower value than 30% and 50% treatment under high intensity. Control, bred full sunlight, was shown the worst photosynthetic activity at measured all light intensity. That result could imply that was caused by photo-inhibition because of long term exposed of shade tolerant plant at high light intensity. Leaf characteristics had not significant different in leaf length, width and area but leaf dry weight had similar trend to photosynthetic activity.

• 한국환경농학회지
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• 제34권3호
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• pp.210-216
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• 2015

BACKGROUND: In korea, sweet persimmon(Diospyros kaki) cultivation is front to abiotic stresses such as frost damage at fruit maturing stage. The cold and rapid freezing stresses are most damaging to fruit production which is most actively progressed in late fall. This study was performed to evaluate the validity of chlorophyll fluorescence imaging(CFI) technology to determine the degree of frost damage in sweet persimmon fruits. METHODS AND RESULTS: The sweet persimmon fruits were measured separately for each treatment(15, 30, 60 minutes) at 24 hours after treatment(HAT) rapid freezing. A CFI FluorCam (FC 1000-H, PSI, Czech Republic) was used to measure the fluorescence images of the fruits. In rapid freezing for 15 minutes, photochemical parameters were not changed. However, in rapid freezing for 30 and 60 minutes, photochemical parameters were lowered. Especially, $F_m$, $F_v$, $F_v/F_m$ and ${\Phi}PSII$ values were declined under rapid freezing. CONCLUSION: In our study, it was clearly indicated that the rapid freezing could be a stress in sweet persimmon fruits. The CFI analysis and its related parameters are applicable as a rapid assessing technique for the determination of frost damage.

• 미생물학회지
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• 제8권1호
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• pp.1-12
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• 1970

Nucleic acid and protein biosynthese of the glucose-bleached Chlorella cells in relation to the process of the chloroplast reformation were traced, by measuring the changes in the amounts of cell constituents and nuclease activities of the cells during the greening process. The contents of RNA and protein of the glucose-bleached cells decreased significantly, shile the contents of nucleotides and amino acids of the cells increased to compared with those of the control, showing that the biosynthetic activities of RNA and protein of the cells were inhibited severely in the glucose-bleaching process. In the early greening process of the glucose-bleached Chlorella cells the contents of RNA and protein of the cells increased significantly, while the contents of nucleotides nad amino acids of the cells increased to compared with those of the control, showing that the biosynthetic activities of RNA and protein of the cells were inhibited severely in the glucose-bleaching process. In the early greening process of the glucose-bleached Chlorella cells the contents of RNA and protein of the cells increased significantly wihout any increase in the chlorophyll contents showing that the massive biosynthese of RNA and protein proceed prior to the chlorophyll bioynthesis in the cells. The phosphate contents in the DNA fraction of the glucose-bleached cells decreased, but the contents of acid-insoluble polyphosphate increased to compared with those of the control in the early greening porcess, exhibiting that the incorporation of the phosphorus from acid-insoluble polyphosphate into DNA was retarded. In the greening process of the glucose-bleached cells the ribonuclease nad deoxyribonuclease activities of the cells decreased to compared with those of the control, although the initial activities of the both enzymes in the cell were far great compared with the control. Although the initial phosphate contents in the lipid fraction of the glucose-bleached Chlorella cells were more great than the control, the phosphate contents in the lipid fraction of the cells decreased in the early greening process to compared with control, and then increased in the late developmental stages in which massive chlorophyll biosynthesis occured.

• Journal of Photoscience
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• 제12권1호
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• pp.33-39
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• 2005

Plants possess the ability to dissipate the excitation energy for the protection of photosynthetic apparatus from absorbed excess light. Heat dissipation is regulated by xanthophyll cycle in thylakoid membranes of chloroplasts. We investigated the mechanistic aspects of xanthophyll cycle-dependent photoprotection against low-temperature photoinhibition in plants. Using barley and rice as chilling-resistant species and sensitive ones, respectively, chilling-induced chlorophyll fluorescence quenching, composition of xanthophyll cycle pigments and mRNA expression of the zeaxanthin epoxidase were examined. Chilled barley plants exhibited little changes in chlorophyll fluorescence quenching either of photochemical or non-photochemical nature and in the photosynthetic electron transport, indicating low reduction state of PS II primary electron acceptor. In contrast to the barley, chilled rice showed a marked decline in those parameters mentioned above, indicating the increased reduction state of PS II primary electron acceptor. In addition, barley plants were shown to have a higher capacity to elevate the pool size of xanthophyll cycle pigments in response to cold stress compared to rice plants. Such species-dependent regulation of xanthophyll cycle activity was correlated with the gene expression level of cold-induced zeaxanthin epoxidase. Chilled rice plants depressed the gene expression of zeaxanthin epoxidase, whereas barley increased its expression in response to cold stress. We suggest that chilling-induced alterations in the pool size of xanthophyll cycle pigments related to its capacity would play an important role in regulating plant's sensitivity to chilling stress.