The response of the freshwater microalga, Chlorella vulgaris, to heavy metal stress was examined based on chlorophyll fluorescence analysis to assess the toxic effects of heavy metals in freshwater ecosystems. When toxic effects were analyzed using regular chlorophyll fluorescence analysis, photosystem II activity(Fv/Fm) decreased significantly when exposed to Cu2+ and Hg2+ for 12 h, and decreased in the order of Hg2+ > Cu2+ > Cd2+ > Ni2+ when exposed for 24h. The effective photochemical quantum yield(Φ′PSII), chlorophyll fluorescence decrease ratio(RFd), minimal fluorescence yield(Fo), and non-photochemical quenching(NPQ), but not photochemical quenching(qP), responded sensitively to Hg2+, Cu2+, and Cd2+. These results suggest that Fv/Fm, as well as Φ′PSII, RFd, Fo, and NPQ could be used to assess the effects of heavy metal ions in freshwater ecosystems. However, because many types of heavy metal ions and toxic compounds co-occur under natural conditions, it is difficult to assess heavy metal toxicity in freshwater ecosystems. When Chlorella was exposed to heavy metal ions for 12 or 24h, Fv/Fm and maximal fluorescence yield(Fm) changed in response to Hg2+ and Cu2+ based on image analysis. However, assessing quantitatively the toxic effects of several heavy metal ions is challenging.

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).

This study was performed to investigate the physiological responses of Oplopanax elatus by water condition.Drought stress was induced by withholding water for 26 days. The results show that PN max, SPAD, gs, E and Ci weresignificantly decreased with decreasing of soil moisture contents. However, AQY and WUE were decreased slightly only at26 day. This implies that photosynthetic rate is reduced due to an inability to regulate water and CO₂exchange through thestomatal. According to JIP analysis, ΦPO, ΨO, ΦEO and PIABS were dramatically decreased at 21 day and 26 day, whichreflects the relative reduction state of the photosystem II. On the other hand, the relative activities per reaction center suchas ABS/RC, TRo/RC were significantly increased at 26 day. Particularly, Dio/RC and DIo/CS increased substantially underdrought stress, indicating that excessive energy was consumed by heat dissipation. These results of chlorophyll a fluores-cence show that the sensitivity changes photosystem II activity. Thus, according to the results, O. elatus was exhibited astrong reduction of photosynthetic activity to approximately 10% soil moisture contents, and JIP parameters could be usefulindicator to monitor the physiological states of O. elatus under drought 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.

Development of transgenic plant with desirable traits to cultivated plant is one of the important procedures in plant molecular breeding. However, applicable assessment of transgenic plant in laboratorial scale is not much except cultivating transgenic plant for a whole life in field condition. Here, we analyzed chlorophyll fluorescence in three transgenic soybean lines with AtMYB44 transcription factor for assessment of photosynthetic activity under abiotic stresses such as drought. Soybean varieties used in this study were ‘Bert’ and ‘Bert’ derived three transgenic soybeans, ‘AtMYB44 CM35101’, ‘AtMYB44 CM2471’, and ‘AtMYB44 CM4481’. Analyzed five different chlorophyll fluorescence variables are maximum PSII quantum yield (QY_max), steady state PSII quantum yield (QY_Lss), steady state non-photochemical quenching (NPQ_Lss), coefficient of photochemical quenching in steady-state (Qp_Lss), and fluorescence declineratio in steady-state (Rfd_Lss). To determine main chlorophyll fluorescence variable affected by abiotic stress, principal component analysis (PCA) was conducted with five chlorophyll fluorescence variables measured from four varieties. QY_Lss and NPQ_Lss were main chlorophyll fluorescence variables to evaluate abiotic stress, particularly in drought stress. In comparison with transgenic soybean lines based on chlorophyll fluorescence variables, ‘AtMYB44 CM2471’ and ‘AtMYB44 CM4481’ are more tolerant to drought than the others. Interestingly, three transgenic soybean lines which have a same AtMYB44 gene with different regions of chromosome revealed the quite different responses of chlorophyll fluorescence to drought treatment.

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.

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.

When three cultivars, “Shinsunchalbyeo”, “Nokmi” and “GW-05-01”, which was collected from native glutinous rice, were exposed to increased salinity stress in exogenous solution and duration of salt stress, leaf relative water content (RWC), root water uptake and chlorophyll fluorescence were observed the significant decrease at ≥500mM NaCl concentration for 4 day stress. These decrease in leaf RWC showed 69%, 77% and 67% for Shinsunchalbeyo, Nokmi and GW-05-01, respectively, in water uptake these effects showed 84%, 85% and 91%. The difference in Fv/Fm of plants treated with 500mM NaCl showed 0.62, 0.68 and 0.78 compared with 0.78, 0.81 and 0.75 in control treatment. The effects of NaCl stress in rice seedlings indicate that the leaf RWC and photosynthetic capacity is more sensitive GW-05-01 in comparison with Shinsunchalbyeo and Nokmi, and water uptake in root is more resistant. Average plant height in Shisunchalbyeo, Nokmi and GW-05-01 showed 107, 102 and 111cm, and the 1000 grains weight were 25.5, 20.3 and 21.8, respectively.

인삼은 연작지 재배가 불가능하고 주산지의 우량 예정지 고갈로 인하여 제주도를 제외하고 국내 전국에서 재배하고 있다. 지역별 기후형태가 상이함에도 불구하고 동일한 해가림 구조로 재배하고 있어 일부지역에서 피해가 발생하고 있어 지역에 적합한 표준 해가림 재배기술이 필요하다고 생각된다. 따라서, 본 연구는 남부지역(밀양, 나주, 해남)에서의 적정 해가림구조를 밝히고자 실시하였다. 실험은 2008년 부산대학교 부속농장(밀양)에 묘삼을 이식하였고 해가림 시설은 차광망(검정 차광망), 차광판(비누수 광반사 차광판), 차광지+망(청색 비누수차광지에 검정색 차광망), 차광지(청색 비누수차광지)를 후주연결식으로 설치하여 삼집내 광량과 온도를 측정하였고(Li-cor사의 LI-2000) 광합성속도와 엽록소 형광반응은 생육하고 있는 2년생 인삼을 이용하여 Li-cor의 LI-6400으로 조사하였다. 해가림 자재별 광량은 차광판과 차광지에서 높은 경향을 보였으며, 차광판의 경우 전주에서의 반사광의 유입으로 삼집내 광량이 높은 경향이 있었고, 차광지의 경우 투광량이 높아 광량이 높게 나타냈다. 차광지+망과 차광망에서는 광량이 낮은 경향이었다. 온도는 차광판이 가장 낮은 경향이었는데 이는 직접광이 삼집내로 투과되지 못한 원인으로 사료되며, 다음으로 차광망, 차광지+망, 차광지 순으로 높은 경향을 보였다. 차광지의 경우 투광량이 높아 인삼에서 고온장해가 생기는 현상이 나타났다. 광합성의 경우, 광강도가 증가함에 따라 광합성속도가 증가하는 경향이 있었고, 해가림 자재에 따라 비교하면 차광판에서 높은 경향을 보였으며, 다음으로 차광망과 차광지+망이 높았고, 차광지에서 낮은 경향이었다. 엽록소 형광반응에서 Fo는 차광판에서 낮은 경향이었으며, 다음으로는 차광망, 차광지+망, 차광지 순으로 높은 경향을 보였다. Fv/Fm에서는 차광판에서 높았고, 차광망, 차광지+망, 차광지 순으로 낮은 경향이 있었다. ETR은 차광판에서 가장 높은 경향이 나타냈으며, 다음으로 차광망, 차광지+망, 차광지로 낮은 경향을 보였다.

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.

For the stable production of high quality tea, the freezing resistance is a very important character. Most of the farmers have planted out-pollinated seeds that are not genetically pure. So, with small sample, a quick and simple method is required to test freezing resistance of lots of germ-plasm and early generation of hybrids. The absorbances(A530 nm) of TTC reduction solution at -5~circC were positively correlated with resistance to photoinhibition of PSII in 6 hour photoinhibitory treatments, being significantly fitted by simple linear regression (R2 =0.64** ). Chlorophyll fluorescence measured by Fv/Fm was found to be very useful in evaluating the relative levels of freezing resistance in tea.

엽녹소형광측정에 의한 수도 내냉성검정의 가능성을 검토하기 위하여 내냉성이 다양한 11개 품종을 1 /5000a pot에 원형직파하여 육성된 재료들을 수잉기에 10℃ 의 저온에 8 일간 처리하여 저온처리전후의 가변형광량( FVAR)과 형광증가속도(F/sun R/)의 변화를 비교하였다. 내냉성이 약한 품종들에서 저온처리에 의한 형광특성들의 감소가 커서 각 품종들의 저온장해정도와 가변형광량 및 형광증가속도의 저온처리전후의 대비지수는 부의 유의상관을 나타내어 이들 형광특성들은 도체형양기관에 나타나는 저온장해의 정도를 판단하는데 유용하게 이용될 수 있을 것으로 판단되었다. 엽록소형광을 이용한 내냉성검정방법은 다량의 육종재료 검정에 정밀성, 경제성, 신속성과 함께 검정에 공시된 개체를 계속 육종에 이용할 수 있어 이의 활용이 기대된다.다.