생육후기(生育後期)의 환경조건(環境條件)에서 토양수분함량(土壤水分含量)이 수수류(類)의 광합성(光合成), 증산(蒸散), 기공저항(氣孔抵抗)의 일변화(日變化)에 미치는 영향(影響)을 비교(比較)할 일적(日的)으로 1985년도(年度) 축산시험장(畜産試驗場)의 포장(圃場)에서 대형(大型) 콘크리트 폿트에 토양수분(土壤水分)을 포장용수량(圃場容水量)의 100, 80, 60 및 40%가 유지되도록 조절(調節)하고 수수와 수수×수단그라스교잡종(交雜

국내의 공공하수처리시설의 고도처리공법은 대부분 A2O 계열과 SBR 계열로 운영되고 있다. SBR 계열의 고도처리시설이 더 많은 개소에 적용되었으나, 대규모 하수처리장은 대부분 A2O 계열의 공법을 적용하기 때문에 가장 많은 양의 하폐수를 고도처리하는 공법이라 할 수 있다. A2O 공법은 혐기조와 무산소조, 호기조로 구성되어있어, 질소 및 인의 동시 제거가 가능하다. 그러나 반송슬러지 내의 용존산소 및 질산성 질소로 인하여 인제거 박테리아의 Luxury uptake 효율을 떨어뜨려 인 제거 효율이 불안정하다는 단점이 있다. 또한 A2O와 같은 고도처리공법을 적용함에도 불구, 방류수 수질기준을 만족시키기 어려운 경우가 종종 발생하여 질소 및 인의 제거효율을 높이는 새로운 공법 개발이 필요한 상황이다. 이에 대한 방안으로 미세조류를 적용한 하폐수처리와 관련된 연구가 활발하게 진행되고 있다. 미세조류는 광합성색소를 가지고 있는 단세포 생물로, 빛 에너지로부터 화학에너지(ATP)를 생성하여 성장할 수 있다. 또한 성장을 위한 영양소로 질소와 인을 필요로 하기 때문에 이를 이용하여 하폐수고도처리가 가능하게 된다. 고도처리공법에 미세조류를 적용하기 위해서는 매일 달라지는 유입수의 성상에 대해 미세조류의 활성이 유지되어야 한다. 이에 본 연구에서는 미세조류의 활성이 저하할 것으로 예상되는 저농도 질소(0, 5, 10, 20 mg-N/L)를 함유한 하수의 유입을 가정하고, 미세조류의 활성이 어떻게 변하는지 관찰하고 활성의 척도로서 광합성량과 호흡량을 측정했다. 그에 따라 미세조류를 적용한 고도처리공법으로 저농도 질소를 함유한 하수를 처리할 수 있는가에 대한 가능성을 평가하고자 했다.

The effects of elevated atmospheric CO2 on growth and photosynthesis of soybean (Glycine max Merr.) were investigated to predict its productivity under elevated CO2 levels in the future. Soybean grown for 6 weeks showed significant increase in vegetative growth, based on plant height, leaf characteristics (area, length, and width), and the SPAD-502 chlorophyll meter value (SPAD value) under elevated CO2 conditions (800 μmol/mol) compared to ambient CO2 conditions (400 μmol/mol). Under elevated CO2 conditions, the photosynthetic rate (A) increased although photosystem II (PS II) photochemical activity (Fv/Fm) decreased. The maximum photosynthetic rate (Amax) was higher under elevated CO2 conditions than under ambient CO2 conditions, whereas the maximum electron transport rate (Jmax) was lower under elevated CO2 conditions compared to ambient CO2 conditions. The optimal temperature for photosynthesis shifted significantly by approximately 3°C under the elevated CO2 conditions. With the increase in temperature, the photosynthetic rate increased below the optimal temperature (approximately 30°C) and decreased above the optimal temperature, whereas the dark respiration rate (Rd) increased continuously regardless of the optimal temperature. The difference in photosynthetic rate between ambient and elevated CO2 conditions was greatest near the optimal temperature. These results indicate that future increases in CO2 will increase productivity by increasing the photosynthetic rate, although it may cause damage to the PS II reaction center as suggested by decreases in Fv/Fm, in soybean.

Background : Management of air temperature are known to primarily affecting on physiological properties and yield in plant. Methods and Results : The effect of air temperature on characteristics of photosynthesis and chlorophyll fluorescence in Cnidium officinal were investigated using growth chamber after cultivating for 24 hours under controlled condition. Net photosyntheis rate, transpiration was measured at 1,000 μmol m-2 s-1 of photon flux density and chlorophyll fluorescence was analyzed by OJIP method. Net photosyntheis rate was highest in treatment of 25℃. Although transpiration rate was lowest, water use efficience was also in treatment of 25℃. Stomatal conductance was mainly influenced from ambient climatric factors such as vapor pressure deficit. As results of chlorophyll fluorescence by OJIP analysis, maximum quantum yield (Fv/Fm) of photosystem II (PSII), PIabs and the relative activities per reaction center such as ABS/RC, DIo/RC were not changed at air temperature. Therefore, elevated air temperatue during short term influence the dark reaction in photosystem through controlling a water use efficience and transpiration. Conclusion : This result show that 25℃ of air temperature may be a adequate temperature to improving the efficiency of photosynthesis in Cnidium officinale.

Background : Recently, some of the previous stuies reported that was useful technique on growth and yield of organically grown ginseng transplantation in a rain shelter greenhouse. This study was conducted to investigate the optimum method of greenhouse shading for ginseng(Panax ginseng C. A. Meyer) cultivaton in the northern area of Ganwon, Korea. Methods and Results : We carried out to select optimal shade materials and light-penetrated ratio among polyethylene film with two-layered polyethylene net(PEF+PEN) and blue-white duplicated PE film(BWD-PEF) in the condition of greenhouse for ginseng cultivation. The order of light-penentrated ratio by shade meterials was PEN(75%)+PEF 〉 PEN(85%)+PEF 〉BWD-PEF(85%) 〉BWD-PEF(90%) and the order of air temperature was BWD-PEF(85%) 〉BWD-PEF(90%) 〉PEN+PEF(85%) 〉PEN+PEF(75%). The net photosynthetic rate was higher in PEN(75%)+PEF than other shading material treatments during growth season including summer high-temperature period. The root weight and yield were increased by 31.2~55.0% and 25.6~52.2%, respectively under PEN+PEF(75%) compared to other shading materials. Conclusion : We concluded that the PEN+PEF(75%) could be a good shading meterails of the greenhouse for organic 4-year-old ginseng cultivation in northern area of Gangwon, Korea.

Plant biomass, photosystem II (PSII) photochemical activity, photosynthetic function, and zinc (Zn) accumulation were investigated in a sorghum-sudangrass hybrid (Sorghum bicolor × S. sudanense) exposed to various Zn concentrations to determine the elimination capacity of Zn from soils. Plant growth and biomass of the sorghum-sudangrass hybrid decreased with increasing Zn concentration. Symptoms of Zn toxicity, i.e., withering and discoloration of old leaves, were found at Zn concentrations over 800 ppm. PSII photochemical activity, as indicated by the values of Fv/Fm and Fv/Fo, decreased significantly three days after exposure to Zn concentrations of 800 ppm or more. Photosynthetic CO2 fixation rate (A) was high between Zn concentrations of 100-200 ppm (22.5 μmol CO2･m –2･s –1), but it declined as Zn concentration increased. At Zn concentrations of 800 and 1600 ppm, A was 14.1 and 1.8 μmol CO2･m –2･s –1, respectively. The patterns of stomatal conductance (gs), transpiration rate (E), and water use efficiency (WUE) were all similar to that of photosynthetic CO2 fixation rate, except for dark respiration (Rd), which showed an opposite pattern. Zn was accumulated in both above- and below-ground parts of plants, but was more in the below-ground parts. Magnesium (Mg) and iron (Fe) concentrations were significantly low in the leaves of plants, and symptoms of Mg or Fe deficiency, such as a decrease in the SPAD value, were found when plants were treated with Zn concentrations above 800 ppm. These results suggest that the sorghum-sudangrass hybrid is able to accumulate Zn to high level in plant body and eliminate it with its rapid growth and high biomass yield.

Background : Management of air temperature are known to primarily affecting on physiological properties and yield in plant. Methods and Results : The effect of air temperature on characteristics of photosynthesis and chlorophyll fluorescence in Schisandra chinensis Baillon were investigated under controlled temperature using growth chamber. Net photosyntheis rate, transpiration was measured at 1,000 μmol m-2 s-1 of photon flux density and chlorophyll fluorescence was analyzed by OJIP method. Net photosyntheis rate and transpiration rate was higher in treatment of 25℃. As results of chlorophyll fluorescence by OJIP analysis, maximum quantum yield (Fv/Fm) of photosystem II (PSII) and PIabs was higher in treatment of 25℃ which reflects the relative reduction state of PSII. But in treatment of 35℃ the relative activities per reaction center such as ABS/RC, DIo/RC were higher than in treatment of 25℃ which implied that the relative reduction of electron transport at PSI and increasement of photo inhibition at reaction center. Conclusion : This result implies that 25℃ of air temperature may be a adequate temperature to improving the efficiency of photosynthesis through controlling a photosystem in Schisandra chinensis Baillon.

High temperature impairs rice grain yield and quality. To understand the effect of high temperature on leaf physiological activity and grain filling, two cultivars of rice that Dongan and Ilpum were exposed to high temperature during ripening stage. Grain filling rate, perfect grain ratio and grain weight of high temperature (27℃±4℃) treated both rice cultivars were decreased than those of control temperature (22℃±4℃) treated. The reduction rates of grain filling ratio, perfect grain ratio and grain weight of high temperature treated to control treated rice were higher in Ilpum than Dongan. Chlorophyll contents of rice leaves under high temperature at early ripening stage were higher than those of control temperature, but those were slowly decreased with no difference between temperature treatment since at mid ripening stage. Although chlorophyll a/b ratio under high temperature was decreased from heading to 15 days after heading, that was gradually increased since 15 days after heading. Protein concentrations of rice leaves for ripening stage was a similar pattern with chlorophyll changes. The rate of photosynthesis at 14 days after heading under high temperature was higher than those of control temperature, but there was no difference at those of 7 and 34 days after heading between two temperature treatment. Free sugars under high temperature treated leaves were lower than control temperature. Consequently, these results exhibit that high temperature accelerate leaf physiological activity as chlorophyll synthesis and photosynthesis rate unlike the deterioration of grain filling.

This study was carried out in order to investigate the photosynthesis response and leaf characteristics of Peucedanum japonicum growing in forest farming. The experiment was performed by leaf mold (pine tree and chestnut tree) and shading levels (0%, 35%, 50% and 75% shading). Light relative intensity was 100% (full sunlight), 60.3% (35% shading), 35.1% (50% shading), and 17.4% (75% shading) respectively. Light response curves of pine-leaf mold and chestnut-leaf mold were the highest in control (full sunlight) and these were getting lower in the higher shading level. Photosynthesis capacity and light saturation point were indicated higher in chestnut-leaf mold within the same shading level. As the shading level increased, maximum photosynthesis rate decreased. And apparent quantum yield was not indicated statistically significant difference from all treatment. Leaf area, leaf length and leaf width were significant higher in 35% shading and control under chestnut-leaf mold in all treatment. As the shading level increased, LAR (leaf area ratio), SLA (specific leaf area) and SPAD value decreased in pine-leaf mold and chestnut-leaf mold. As a result of surveying the whole experiment, P. japonicum is judged better growth and higher yield by maintaining 35% shading (relative light intensity 60%) under chestnut-leaf mold in forest farming.

‘Hwasu 3551’(HS) 과 ‘White-Red Lip’(WR)을 대상으로 저 온이 호접란의 생육단계별 광합성에 미치는 영향을 알아보았다. 실 험에 사용하기 위해 조직배양을 통해 번식된 유묘들을 4주간 외부 환경에 순화시킨 후(1개월 묘), 28/26oC(HT)의 식물생육상에서 재배하였다. HT에서 0(1개월 묘), 2(3개월 묘), 4 개월(5개월 묘) 간 재배된 식물들을 21/19oC(LT)의 식물생육상으로 옮겨 3개월 간 저온처리 하였고, 각 식물생육상의 일장은 12시간(06시.18시), 광도는 110±10μmol·m-2·s-1 PPF를 유지하였다. 저온의 영향을 알 아보기 위해서 각 온도 및 생육단계별로 영양생장과 24시간 동안의 CO2흡수율을 측정하였다. 전반적으로 호접란의 광합성은 CO2흡 수 양상에 따라 페이즈 I부터 IV까지 나뉘어지는 전형적인 CAM 광합성을 보였으며, 3개월간 저온에서 재배 후 하루 동안 흡수한 총 CO2의 양과 영양생장의 증가정도는 HT 조건을 유지한 처리군에 비해 감소하였다. 특히 3개월 묘를 LT에서 3개월간 재배하였을 떄, HS, WR 두 품종의 페이즈 III 동안 CO2흡수율은 각각 -1.36, -0.60μmol·m-2·s-1까지 감소하여 CO2누출 (CO2 leakage)양상을 보였다. 이로 인해 낮 동안의 총 CO2흡수량이 감소하였고, 영양 생 장량 역시 감소하였다. 1개월 묘를 LT조건에서 재배하였을 때 신 엽의 발생은 통계적으로 유의성 있게 감소하였지만, 5개월 묘의 경 우에는 감소하지 않았고, 단지 엽장의 증가정도만 감소하였다. 이 러한 결과는 5개월 묘에서 저온의 영향이 작았고, 영양생장이 계속 유지되었다는 것을 나타낸다. 호접란의 재배에 있어서 이러한 접근 방식은 재배 스케줄을 조절하거나 기존의 방법을 개선하여 재배비 용을 절감하는 대에 도움이 될 수 있을 것이다.

In the results of investigating the role of LED light quality in enhancing the ornamental value of indoor foliage plants, amber and red light increased plant height, leaf width, and leaf stalk, and the consequent tree shape decreased the ornamental value. The chlorophyll content increased significantly under white light and compound light. With regard to the effect of plant leaf color on ornamental value, the value of lightness was markedly enhanced by red light. As to the functionality of plants according to photosynthetic activity, plants such as Dieffenbachia, Clusia, and Dracaena were found favorable to those staying indoors for a longtime from morning to evening. Spathiphyllum, and Ficus were found to be recommendable for indoor spaces used actively during afternoon because their photosynthesis was activated in the afternoon. With regard to power consumption according to light quality, white light consumed 119 W/hour, around 45% lower than that of fluorescent lamps, so it is considered the optimal artificial light quality that can enhance energy efficiency. Red light consumed 72 W/hour, only 33% of that of fluorescent lamps, but it was not considered the optimal light quality because plant growth was poor under the light quality. White light and compound light were found to be the ideal light sources for improving the functionality and ornamental value of indoor plants and reducing the cost of maintenance, but because compound light hinders people from recognizing the original color of plants and makes their eyes easily tired, white light was considered the optimal light satisfying all of the ornamental value, economic efficiency and functionality resulting from plant growth.

‘식물의 광합성'은 생명 과학 영역에서 다루는 개념이지만, 실험을 통해 출입하는 기체를 확인하기 위해서는 BTB 용액의 색변화에 대한 화학적 이해가 바탕이 되어야 한다. 이 연구의 목적은 BTB 용액을 사용한 광합성 실험에서 BTB 용액의 변색 과정과 관련하여 ’광합성' 실험의 문제를 살펴보고, 이를 개선하기 위한 자료를 제공하는 것이다. 이를 위해『2007 개정 과학과 교육과정』에 따른 중학교 「과학 1」교과서 8종과 『7차 과학과 교육과정』에 따른 중학교 「과학 2」교과서 8종을 대상으로 실험에 사용된 BTB 용액의 색변화와 이에 대한 설명을 분석하였고, 예비교사 202명을 대상으로 설문을 실시하였다. 교과서 분석 결과, ‘광합성’ 실험에 사용한 BTB 용액의 초기 색깔은 청색과 녹색 두 가지로 나타났으며, 색깔이 같은 BTB 용액을 사용하였음에도 불구하고 광합성 이후의 색변화에 있어서 교과서 별로 다르게 제시하고 있어 적절한 BTB 용액의 선정과 색변화를 판단하는데 혼동의 여지가 있었다. 또한 BTB의 변색에 대한 교과서의 설명은 이산화탄소의 양에 따른 색을 제시하는 방식, 액성에 따른 색을 제시하는 방식 등으로 분류할 수 있었으나, 각 방식은 화학적 이해를 돕기에 미흡한 점이 있었다. 예비 교사들의 BTB 용액의 변색에 대한 응답은 초기 BTB 용액의 색깔이 청색이거나 녹색인 것과 상관없이 광합성 후에 청색으로 된다는 유형 1, 모두 녹색으로 돌아간다는 유형 2, 처음 사용한 BTB 용액의 색깔 즉, 청색은 청색으로 녹색은 녹색으로 돌아간다는 유형 3으로 나눌 수 있었다. 이들의 구체적인 변색 이유를 분석한 결과, 유형 1의 경우, 산소의 발생으로 인해 용액의 액성이 염기성이 된다고 생각하는 비율이 높았으며, 유형 2의 경우, 초기 용액의 액성에 대한 고려 없이 이산화탄소가 사라지면 중성이 되기 때문이라고 인식하고 있었다. 유형별로 화학적 이해의 수준이 다르게 나타났으며, 예비교사의 전공에 따라 유형별 비율은 차이가 있었다. BTB 용액의 색변화에 대한 혼동과 불완전한 이해를 개선하기 위해서는 광합성 실험에 적합한 표준 BTB 용액의 제조 방법을 개발하고, 교과서에서 BTB 용액의 변색 이유에 대한 화학적 설명이 추가적으로 제시될 필요가 있다.

Korean ginseng has been used for thousands of years as an important medicinal plant. Lime-Bordeaux mixture (LBM) was made with copper sulfate and quicklime, which was sprayed instead of pesticides in ginseng field. Net photosynthesis (PN) was compared between Treatment and Non-treatment of LBM in 3 Year Old Ginseng. PN in control plot recorded 2.94μmol (CO2) m-2s-1 at the first day of experiment, which was similar until the last day of experiment. However, The PN in LBM recorded 2.23μmol (CO2) m-2s-1, which was lower than that in control plot. As time goes by, The PN in LBM was gradually increased up to 3.21μmol (CO2) m-2s-1 and finally, it was similar with that in control plot at 7th day as a 3.20μmol (CO2) m-2s-1).

This study was conducted to investigate the changes of chlorophyll contents, chlorophyll fluorescence, photosynthetic parameters, and leaf growth of Synurus deltoides under different shading treatments. S. deltoides was grown under non-treated (full sunlight) and three different shading conditions (Shaded 88~93%, 65~75%, and 45%~55%). Light compensation point (Lcomp), dark respiration (Dresp), maximum photosynthesis rate (Pnmax), photo respiration rate (Presp), carboxylation efficiency (Φcarb), and photochemical efficiency were decreased with increasing shading level; However, CO2 compensation point (CO2 comp), total chlorophyll content, and specific leaf area (SLA) were shown the opposite trend. S. deltoides under 88~93% treatment showed the lowest photosynthetic activity such as maximum photosynthetic rate (Pnmax), photochemical efficiency, and CO2 compensation point (CO2 comp). Therefore, photosynthetic activity will be sharply decreased with a long period of 8~12% of full sunlight. With the shading level decreased, carotenoid content and non-photochemical fluorescence quenching (NPQ) increased to prevent excessive light damage. This result suggested that growth and physiology of S. deltoides adapted to high light intensity through regulating its internal mechanism.