Chlorophyll-a and its degradation products (pheopigment) contained in the sediment were determined to evaluate the eutrophication status in the downstream of Nakdong River. The chlorophyll-a and pheopigment concentrations of sediment ranged 11-646 mg μ

오염부하량이 높은 경안천과 오염부하량이 낮은 철원북방 비무장지대내 토교저수지에서 식물플랑크톤의 크기별 현존량과 chlorophyll a농도에 대한 계절적 변화 및 환경요인과의 상호관계를 조사하였다. 또한 식물 플랑크톤의 크기를 고려하여 > 8μm, 3-8μm, <3μm 세포 크기별로 분획하여 현존량과 chl. a 농도를 관찰하였다. 물리.화학적 환경요인은 경안천이 토교저수지보다 높게 나타났다. 식물플랑크톤 현존량은 경안천에서

시아해의 수질환경과 식물플랑크톤 생물량의 계절변동 특성 및 식물플랑크톤 생물량변동에 영향을 미치는 환경요인을 파악하기 위해 1995년 2월,4월,7월과 10월 4회에 걸쳐 계절별로 23개 관측점의 표층과 저층 해수를 대상으로 현장조사를 실시하였다. 결과, 시아해는 2월에 최저수온, 8월에 최고 수온을 나타내나, 염분은 6, 7월에 높고 겨울에 낮은 특성을 나타내었으며, 연중 빠른 유속과 조석혼합 등으로 수층 간 혼합된 양상과 매우 낮은 투명도를 나타내고

In order to investigate the properties in distribution and movement of anchovy school catches by the lift net in the Kamak bay and their relation to the environmental factors, I. e., the amount of chlorophyll-a and turbidity were observed from June to August in 1997 and compared with the catch of anchovy by the lift net. The results obtained are summarized as follows;1) The amount of chlorophyll-a ranged from 4.0 to 12.0 mg/m3 on July and from 3.0 to 15.0 mg/m3 on August in horizontal distribution, the amount of chlorophyll-a ranged from 3.0 to 8.0mg/m3 on June, from 5.5 to 11.6 mg/㎥ on July, and from 6.0 to 11.1 mg/m3 on July and from 1.0 to 6.0ppm on August, respectively. 2) Anchovy school can be presurmed, they are come from north of bay, visited and distributed through east of bay at the middle of June. Moreover, they spreaded in all bay. Then gradually, when July arrive, they go to the south the nearest the coasts, and they are outflow through the south entrance of bay at the end of August.3) The catch of anchovy was highest on July, poor second on August, and lowest on June. The chlorophyll-a and the turbidity influenced remarkably on the distribution and movement of anchovy school and the influence of chlorophyll-a was alrgest.

The objective of this study was to find a rapid determination of the hot air stress in maize (Zea mays L.) leaves using a portable chlorophyll fluorescence imaging instrument. To assess the photosynthetic activity of maize leaves, an imaging analysis of the photochemical responses of maize was performed with chlorophyll fluorescence camera. The observed chlorophyll imaging photos were numerically transformed to the photochemical parameters on the basis of chlorophyll a fluorescence. Chlorophyll a fluorescence imaging (CFI) method showed that a rapid decrease in maximum fluorescence intensity (Fm) of leaf occurred under hot air stress. Although no change was observed in the maximum quantum yield (Fv/Fm) of the hot air stressed maize leaves, the other photochemical parameters such as maximum fluorescence intensity (Fm) and Maximum fluorescence value (Fp) were relatively lowered after hot air stress. In hot air stressed maize leaves, an increase was observed in the nonphotoquenching (NPQ) and decrease in the effective quantum yield of photochemical energy conversion in photosystem II (Φ PSII). Thus, NPQ and ΦPSII were available to be determined non-destructively in maize leaves under hot air stress. Our results clearly indicated that the hot air could be a source of stress in maize leaves. Thus, the CFI analysis along with its related parameters can be used as a rapid indicating technique for the determining hot air stress in plants.

Background : The ginseng cool-season and semi-shade plant undergoes photosynthesis smoothly at low temperature in the morning but its efficiency falls at high temperature in the afternoon. Therefore, if it is possible to control light transmission rates (LTR) every day, it will be able to draw an ideal result in the ginseng growth by attracting a lot of lights before 11am and attracting few lights after 11am which is the affect point of the photosynthetic efficiency. Methods and Results : While installing the sun shading facility that could control the light environment based on 11am and surveying the ginseng's growth and photosynthetic characteristics. The photosynthetic efficiency increased 2.81 times compared to conventional practices without the change of the chlorophyll content although LTR was high because of the low temperature in the morning. The aboveground part growth of the ginseng which adapted to the light environment increased to influence the root weight, when the ginseng was 4 years old, the fresh root weight was averagely 33.3g per plant which increased by 81% than 18.4g of conventional practices. Conclusion : If the light environment management according with the photosynthetic nature of the ginseng is conducted based on 11am, it will be possible to produce a large capacity and excellent-quality ginseng.

Background : Excessively high concentration of sodium ion causednutrient deficiency and significantly decrease growth. This study was carried out to determine the limiting concentration range of sodium ion in the soil of ginseng field. Methods and Results : The growth of the ginseng cultivar Chunpoong reduced with increase in salinity, and the rate of growth reduction was higher in shoots than that of roots. Particularly, ginseng plants cultivated at high level of nitrate nitrogen or sodium may suffer delayed development and stunted growth. Chlorophyll damage occurred on the leaves of ginseng planted in relatively high levels (> 0.2 c㏖+/㎏) of sodium ion, as determined by the fluorescence reaction. The incidence of physiological disorder in ginseng cultivated at 249 sites was correlated with the concentration of sodium ion in the soils. About 74% of ginseng fields in which physiological disorders occurred had concentrations of sodium ion in soil greater than 0.2 c㏖+/㎏. In contrast, the concentration of sodium ions at 51 of 85 sites where no damage occurred was relatively (0.05 c㏖+/㎏- 0.15 c +/㎏). Conclusions : The concentration of sodium ion in soil of ginseng fields can be classified into three levels optimum (≤ 0.15), permissible allowance (0.15 - 0.2) and excessive (> 0.2).

The response of the freshwater microalga Chlorella vulgaris to mercuric ion (Hg2+) stress was examined using chlorophyll a fluorescence image analysis and O-J-I-P analysis as a way to monitor the toxic effects of mercury on water ecosystems. The levels of photosynthetic pigments, such as chlorophyll a and b and carotenoids, decreased with increasing Hg2+ concentration. The maximum photochemical efficiency of photosystem Ⅱ(Fv/Fm) changed remarkably with increasing Hg2+ concentration and treatment time. In particular, above 200 μM Hg2+, considerable mercury toxicity was seen within 2 h. The chlorophyll a fluorescence transient O-J-I-P was also remarkably affected by Hg2+; the fluorescence emission decreased considerably in steps J, I, and P with an increase in Hg2+ concentration when treated for 4 h. Subsequently, the JIP-test parameters (Fm, Fv/Fo, RC/CS, TRo/CS, ETo/CS, ΦPO, ΨO and ΦEO) decreased with increasing Hg2+ concentration, while N, Sm, ABS/RC, DIo/RC and DIo/CS increased. Therefore, a useful biomarker for investigating mercury stress in water ecosystems, and the parameters Fm, ΦPO, ΨO, and RC/CS can be used to monitor the environmental stress in water ecosystems quantitatively.

As cool-season plant, Panax ginseng C. A. Meyer is planted under shade-installation with tall front and low rear. However, at different planting positions, distinct differences come out because ginseng grows at the same position within 3~5 years and the growth circumstance changes a lot by the shade-installation. So, in this study, changes of temperature, photosynthesis and chlorophyll fluorescence with varieties of shading material and planting position were investigated. Light transmittances by polyethylene shade net and silver-coated shading plate as planting materials were measured according to different planting positions. Photosynthetic rate and chlorophyll fluorescence were measured by LI-6400-40 (Li-Cor). According to different planting positions, light intensity was higher in silver-coated shading plate than in polyethylene shade net, and higher at front than rear. Also, photosynthetic rate showed the same tendency, which had a positive correlation to light intensity. But this treatment caused a lower Fo compared with polyethylene shade net because of the stress by light and temperature. Also, Fv/Fm and ETR were higher in silver-coated shading plate. Fo was similar at front and rear according to silver-coated shading plate and ETR was higher at front.

인삼의 해가림구조에서 차광판 및 차광망의 차광재료 차이에 따른 인삼 재배포의 광량 및 미기상 반응과 광수용체로 작용하는 엽록소 함량의 변화를 조사하여 인삼생육에 적합한 해가림 차광재료의 표준화를 위한 기초 자료를 제공하고자 한 본 연구의 결과를 요약하면 아래와 같다. 1. 차광재료에 따라 맑은 날의 광량은 차광판이 차광망에 비해 70 ~ 76%, 흐린 날은 77 ~ 82% 수준으로 감소되는 양상을 나타내었다. 2. 두둑위치 중 전주의 경우는 하루 총 누적광량에 대비해 맑은 날의 경우 39% 수준, 흐린 날의 경우 51% 누적광량이 높은 양상을 나타내며, 중앙 및 후주행은 맑은 날 및 흐린 날 구분 없이 모두 하루 총 누적광량에 비해 낮은 양상을 나타내므로, 두둑위치에 따른 누적광량의 차이가 분명하였으며, 차광재료에 관계없이 두둑위치에 따라서는 전주 > 중앙 > 후주행의 순으로 광량이 낮아지는 양상을 나타내었다. 3. 차광재료에 따라 차광망이 차광판에 비하여 높은 온도를 유지하였고, 두둑위치에 따라 차광망이 차광판 보다 1.9~3.1℃ 높은 양상을 나타내었다. 4. 차광재료별 맑은 날의 평균 누적온도는 외부온도 대비차광판의 경우 7.3% 감소하는 양상을 나타내었으나, 차광망의 경우 0.7% 증가되는 양상을 나타내었고, 흐린 날의 평균 누적온도는 차광판의 경우 0.7% 감소하는 양상을, 차광망의 경우 1.6% 증가하는 양상을 보였다. 5. 차광재료에 따른 두둑위치별 일일 누적온도의 차이를 비교해 보면 차광망이 차광판에 비해 맑은 날의 경우 전주, 중간 및 후주행이 각각 7.0, 7.8 및 8.8% 높은 양상을 나타내고, 흐린 날의 경우 각각 1.7, 1.6 및 3.5% 높은 양상을 나타내어 두둑위치에 관계없이 차광판이 차광망에 비해 온도가 낮은 양상을 나타내었다. 6. 엽록소 SPAD 값은 전주와 중앙의 두둑위치에서는 차광판이 차광망에 비하여 높게 나타났고 후주에서는 차이가 없었다.

This study was conducted to investigate the influence of shading material on the chlorophyll fluorescence, photosynthesis, transpiration, stomatal conductance and its any correlations in Panax ginseng C.A.Meyer. Fo was higher in polyethylene shade net than in silver-coated shading plate, but this treatment caused a lower Fm in comparison with silver-coated shading plate. Also, Fv/Fm and PhiPS2 showed higher in silver-coated shading plate than in polyethylene shade net. The relationship between net photosynthetic rate and transpiration, stomatal conductance were increased as the PAR (Photosynthetic active radiation) was increased and reached maximum at the 200-400 μmol/m2/s of PAR in all of leaves, and the higher in silver-coated shading plate than in polyethylene shade net. A linear equation was obtained between net photosynthetic rate and transpiration, net photosynthetic rate and stomatal conductance. SPAD was higher in silver-coated shading plate than in polyethylene shade net.