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.
The effects of cadmium ions (Cd2+) on the Chl a fluorescence of Ricciocarpos natans were investigated in order to determine whether Chl fluorescence can be used as a biomarker to estimate the physiological responses of plants to cadmium stress. In all plants treated with Cd2+, the image of Fv/Fm, which represents the maximum photochemical efficiency of PSⅡ, changed as the Cd2+ concentration increased, when treated for 48 h or more. Changes of ΦPSⅡ and QP images were recognized even at 10 μM Cd2+. The Chl a O-J-I-P fluorescence transient was also affected even at 10 μM Cd2+. The fluorescence yield decreased considerably in steps J, I and P in plants treated with Cd2+, although a typical polyphasic rise was observed in non-treated plants. The Chl fluorescence parameters, Fm, Fv/Fo, Sm, SFIabs, PIabs and ETo/CS, decreased as the Cd2+ concentration increased, while the Mo and Kn parameters increased. Peroxidase activity decreased significantly and catalase activity increased as the Cd2+ concentration increased. Because of its sensitivity to Cd2+ Ricciocarpos natans is useful in experiments investigating the responses of plants to cadmium exposure. Several parameters (Fm, Fv/Fo, Sm, SFIabs, PIabs, ETo/CS, Mo and Kn) can be applied to determine quantitatively the physiological states of plants under cadmium stress.
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.
우리나라에 천연분포하는 흑오미자 4종류(자웅동주 제주 #41, #6, 숫그루, 암그루), 오미자 및 남오미자의 잎의 형태적 특성과 엽록소 함량 변이를 조사한 결과는 다음과 같다. 오미자과의 잎 형질, 기공 및 목부 해부학적 특성을 조사한 결과, 수종 간 많은 차이가 있었으며, 흑오미자 4종류 내에서도 암그루, 숫그루 및 자웅동주 개체 간 많은 차이를 보였다. 잎의 길이는 남오미자가 가장 크고 다음이 오미자, 흑오미자 순이었으며, 흑오미자 4종류에서는 암그루가 가장 크고 자웅동주 개체가 중간이었다. 엽병길이는 흑오미자가 오미자와 남오미자에 비해 2배 이상 길었다. 기공길이에서는 흑오미자가 92.5~105.9 μm, 오미자가 79.9 μm, 남오미자가 76.2 μm 로 흑오미자의 기공길이가 길었으며, 기공 폭에서도 유사한 경향을 보여 흑오미자의 기공 크기가 큰 것으로 나타났으나 기공밀도는 오미자나 남오미자에 비해 낮았다. 도관요소 및 목부섬유의 크기도 기공과 유사한 경향을 보였으며, 흑오미자 4종류 내에서도 자웅동주와 암그루, 숫그루 간 차이를 보였다. 엽록소 함량조사 결과 종 간 및 개체 간 변이가 크게 나타났으며, 흑오미자와 남오미자의 SPAD-501 값은 각각 38.8±6.7, 39.5±8.2로 큰 차이를 볼 수 없었으나, 오미자는 SPAD-501 값이 29.2±6.2로 다른 두 수종에 비하여 매우 낮은 값을 나타내었다.
The effects of Cd2+ ions on the Chl a fluorescence of 5 hydrophytes (e.g. Lemna, Salvinia, Ricciocarp, Nymph, Typha plants) were investigated in order to select Cd2+-sensitive plant species and to get informations on physiological responses of plants to Cd2+ stress. Lemna plants were most sensitive to cadmium stress, while Nymph plants were tolerant. However, in all Cd2+-treated plants, Fv/Fm, the maximum photochemical efficiency of PSⅡ, decreased in proportion to the increase of Cd2+ concentration and treatment time. The Chl a fluorescence transient O-J-I-P was also considerably affected by Cd2+ ions; the fluorescence yield decreased considerably in steps J, I and P in Cd2+ treated plants, although it followed a typical polyphasic rise in non-treated plants. In Lemna plants, the functional parameters, ABS/CS, TRo/CS와 ETo/CS and RC/CS, decreased in proportion to the increase of Cd2+ concentration, while N, Mo and Kn increased. The structural parameters, Φpo, Φpo/(1-Φpo), Plabs, SFlabs, Kp and RC/ABS, also decreased according to the increase of Cd2+ concentration. Consequently, Lemna plants will be useful as a experimental model system to investigate responses of plants. And several functional or structural parameters could be applied to determine quantitatively the physiological states of plants under stresses.
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.
4가지 다른 광도조건의 비음처리구에서 2년간 생육한 먼나무 묘목의 총 엽록소 함량은 비음처리 강도가 높아질수록 총 엽록소 함량도 큰 값을 나타냈다. 광합성 특성을 알아보기 위해 조사된 광합성 능력, 엽육내 CO2 농도, 수분이용효율 모두 무처리에서 가장 높은 광합성 효율을 나타냈으며 비음처리별 비교에서도 광도가 낮아질수록 낮은 광합성 효율을 나타냈다. 특히, 가장 낮은 광도조건인 70% 차광처리구는 높은 광도조건에서 가장 낮은 광합성 효율을 나타냈는데 이는 낮은 광도조건에 순화된 광합성 기구가 높은 광도 조건에 적응하지 못한 결과로 사료된다. 잎의 형태적 특성에서는 광도조건이 낮을수록 큰 엽면적을 나타냈으며 단위면적당 건중량은 무처리에서 가장 큰 값을 나타냈다.
Illicium anisatum was bred under four different light intensity. Those condition were full sunlight(PPFD 1600μmol m-2 s-1), 30% treatment(PPFD 400 μmol m-2 s-1), 50% treatment(PPFD 250 μmol m-2 s-1) and 70% treatment(PPFD 100 μmol 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 CO2 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 photoinhibition 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.
약용 및 박과접목묘의 대목으로 이용되는 안동대목 유묘의 생장과 형태는 접목 효율과 접목묘의 상품성에 커다란 영향을 미친다. 본 연구는 박과대목으로 이용되고 있는 양질의 안동대목 유묘 생산에 관한 정보를 제공하고자 차광처리(백색, 적색 및 알루미늄 코팅 부직포)가 안동대목의 유묘 생장과 자엽의 엽록소 함량에 미치는 영향을 조사하였던 바 그 결과를 요약하면 다음과 같다. 1. 초장과 하배축 길이는 백색부직포 처리에서 가장 길었던 반면, 본엽의 크기 및 하배축 직경은 적색부직포 처리에서 가장 크고, 굵었다. 2. 무차광에 비하여 부직포의 색상에 따라 특정 부위의 건물중이 감소하는 경향이 있었다. 백색부직포 처리는 자엽의 건물중이, 적색부직포 처리는 자엽과 본엽의 건물중이, 알루미늄 코팅 부직포 처리는 본엽, 하배축과 뿌리의 건물중이 현저히 감소되어 전체 건물중은 무차광, 백색, 적색 및 알루미늄 코팅 부직포 처리 순으로 감소하였다. 3. 자엽의 엽록소 함량은 부직포의 색상에 따른 차이가 없었다 할지라도 무차광에 비하여 부직포로 차광시 감소되었다. 4. 이상의 결과로부터 안동대목의 육묘시 무차광이 최선이나, 차광을 해야 한다면 백색 또는 적색 부직포를 이용해야 할 것이다.
The diurnal changes of chlorophyll fluorescence and antioxidative enzyme activity were investigated in the leaves from four subtropical plant species (Crinum asiaticum var. japonicum Bak., Osmanthus insularis Koidz., Asplenium antiquum Makino and Chloranthus glaber Makino) under the natural habitats in summer and winter. The intensity of chlorophyll fluorescence was lower in O-, I-, J-, P-steps of O-J-I-P transient in winter than summer, and prominent diurnal change was not found in the fluorescence intensity of four subtropical plant species in winter. The activity and isoenzyme pattern of SOD and catalase did irregularly change seasonally and diurnally in four subtropical plant species. In contrast, the peroxidase activity and isoenzyme pattern was different depending on plant species and growth seasons; The activity increased slightly more in winter than in summer in four subtropical plant species, and several isoenzymes appeared in the leaves from C. asiaticum var. japonicum, O. insularis and A. antiquum in winter.
This study was conducted to investigate the changes of chlorophyll contents and chlorophyll fluorescence in barley(Hordeum vulgare L.) 7 day old seedling treated with 0.2M, 0.4M, 0.6M, 0.8M, and 1.0M NaCl concentration containing Hepes buffer(pH 7.5). Barley was affected by NaCl treatment. The chlorophyll a, b and carotenoid of barley decreased with an increase in NaCl concentration. However, chlorophyll a, b and carotenoid of barley were not greatly influenced by o.8M and 1.0M NaCl. Fv, Fv/Fm and qP were gradually decreased by higher concentration of NaCl. qP, qNP, qR and qE were gradually decreased by 6hr. During barley chloroplast was development NaCl affected chlorophyll synthesis than photosynthetic activity. Whereas barley seedling leaves were more influenced photosynthetic activity than chlorophyll contents by NaCl.