• ALGAE
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• v.24 no.2
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• pp.93-104
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• 2009

Imaging-PAM fluorometry was used to assess the chlorophyll a fluorescence parameter ${\Phi}_{PSII}$ (effective quantum yield) in Frcus vesiculosus. F. disttchus. ssp. distichus and AscophyIIum nodosum. The objective was to show variadon in fluorescence yield associated with age and frond organ, and to illustrate the spatial scales at which photosynthetic parameters vary on fucoid thalli. In addition, our species represented taxa in different but related genera, species with different ecoloeies (rock pool and non rock pool species), morphologies (with and without air bladders) and longevities (several to 20 or more years). A further objective was to determine the extent to which photosynthetic parameters reflected these differences- Effective quantum yield declined substantially with age in F. vesiculosus and F. distichus ssp. distichus, whereas ${\Phi}_{PSII}$ in A. nodosum was maximal after three years. In A. nodosum ${\Phi}_{PSII}$ was still high in branch segments at least seven years old. Older branches of A. nodosum showed relatively higher and more homogeneous photosynthetic capacity relative to Fucus species. Surfaces of air bladders in A. nodosum and F. vesicu- losus had ${\Phi}_{PSII}$ that was not significantly different from the highest rates, achieved in these species. The heterogene- ity of photosynthetic efficiency is consistent with morphological and developmental differences among the species and their ecology. in particular the longevity of A. nodosum fronds.

• Journal of Environmental Science International
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• v.14 no.4
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• pp.389-395
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• 2005

The changes of O-J-I-P transients were investigated using leaves of four subtropical plant species (Crinum asiaticum var. japonicum, Osmanthus insularis, Chloranthus glaber and Asplenium antiquum) under the natural conditions in winter, in order to select the stress indicators for diagnosing physiological states of plants under low temperature. In the O-J-I-P transients of these species, the fluorescence intensity was found to be higher in O-step and lower in P-step in winter than in summer. Particularly, the fluorescence intensity of the P-step in Crinum asiaticum var. japonicum was lower than those of other three plant species, indicating that Crinum asiaticum var. japonicum is the most sensitive to low temperature. Of the chlorophyll fluorescence parameters derived from O-J-I-P transients of four subtropical plants, Fm, Fv/Fo, ABS/CS, TRo/CS, $\phi_{po}$ and $\phi_{po}/(1-\phi_{po})$ decreased significantly with the increase of Fo, Sm, N, EToICS, ETo/RC and $\psi_o/(1-\psi_o)$ depending on temperature drop in winter. Therefore, these parameters could be used as indicators for estimating low temperature stress and diagnosing physiological states of plants under the natural conditions in winter.

• Korean Journal of Medicinal Crop Science
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• v.20 no.5
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• pp.320-330
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• 2012

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 ($L_{comp}$), dark respiration ($D_{resp}$), maximum photosynthesis rate ($Pn_{max}$), photo respiration rate ($P_{resp}$), carboxylation efficiency ($\Phi_{carb}$), and photochemical efficiency were decreased with increasing shading level; However, $CO_2$ compensation point ($CO_{2\;comp}$), 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 ($Pn_{max}$), photochemical efficiency, and $CO_2$ compensation point ($CO_{2\;comp}$). 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.

• Korean Journal of Environmental Biology
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• v.22 no.1
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• pp.233-241
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• 2004

Chlorophyll fluorescence and antioxidative enzyme activity were investigated from leaves of Crinum asiaticum var. japonicum under the natural condition in winter, in order to monitor plant response and physiological states such as vitality, productivity and so on. In the O-J-I-P transients, the fluorescence intensity of J, I, P-step decreased remarkably depending on temperature drop in winter. The photochemical efficiencies of PSII, Fv/Fm, were significantly low in late winter with decrease of Fm. These results indicate that Crinum plants were affected by seasonal drop of temperature. The catalase activity significantly decreased depending on temperature drop in winter. However, the activity of superoxide dismutase ascorbate peroxidase and peroxidase slightly increased in winter while some isoenzymes appeared in winter. These results, with the remarkable decrease of Ev/Fm in winter, represent that Crinum plants were exposed to oxidative stress and subsequently damaged leading to cell death.

• Journal of Ginseng Research
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• v.16 no.2
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• pp.124-128
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• 1992

Vsing the phosphorylated thylakoid membrane induced by 5-35kLux of light intensities, we investigated the chlorophyll nuorescence quenching of PSII and the phosphorylation of LHCPII i in relation to the chlorophyll-bleaching of Panax ginseng C.A. Meyer. In the Presence of DCMU, both of the fluorescence yield of non-phosphorylated thylakoid and the rate of fluorescence quencing dependent on the Phosphorylation were high p. ginseng more then Glyine max L. And at the high light F intensity (above 25 kLux) the fluorescence quenching rate of p. ginseng compared with that of G. max reached nearly to 2 times. The LHCPII of P. ginseng was composed of 3 major Polypeptides (24.5, 26 and 27kD) and 3 minor polypeptides (24, 25.3 and 28.3kD) in the region of 24-29kD and differed, from G. max in both of the number and quantity of polypeptides. Among these polypeptides, the phosphorylated polypeptide dependent on the light intensity was 24kD in P. ginseng.

• Korean Journal of Environmental Agriculture
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• v.34 no.3
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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.

• Horticultural Science & Technology
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• v.19 no.2
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• pp.149-152
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• 2001

Leaf chlorophyll fluorescence capable to estimate $CO_2$ assimilation was compared among three citrus rookstocks: trifoliate orange (Poncitrus trifoliate L.), 'Flying Dragon' (Poncitrus trifoliate L. var. monstrosa) and citromelo (Poncitrus trifoliate L.${\times}$Citrus paradisi), as well as among satsuma mandarin (Citrus unshiu cv. Nichinan No.1) grafted on the 3 rootstocks. Citromelo, the most vigorous rootstock; and 'trifoliate orange'; the most common cultivar and moderate rootstocks gave the same potential and actual quantum yields, whereas 'Flying Dragon' (very dwarf) had lower values due to a higher Fo and Fs for fluorescence obtained from dark-adapted and light-adapted leaves, respectively. These findings show that the absorbed photon energy was dissipated more as fluorescence from the antena chlorophyll in 'Flying Dragon' than trifoliate orange or 'swingle' citrimelo. The satsuma mandarins grafted on these rootstocks did not, however, show the differences observed in the rootstocks by having all the same potential and actual quantum yields. It is suggested that the rootsocks do not potentially or actually electron transport in the Photosystem II (PS II) of satsuma mandarin grafted on the 3 rootstocks.

• Journal of Crop Science and Biotechnology
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• v.11 no.1
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• pp.75-82
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• 2008

Functional stay-green is a beneficial trait that may increase grain yield through the sustained photosynthetic competence during monocarpic senescence in cereal crops. The temporal changes of photosynthesis and related characteristics throughout the grain filling period of a stay-green japonica rice "SNU-SG1" was compared in growth chamber conditions with three high-yielding cultivars(HYVs) and their $F_1$ hybrids with SNU-SG1. SNU-SG1 exhibited a typical characteristic of functional stay-green in terms of chlorophyll degradation and photosynthetic competence during grain filling. According to the photosynthesis-light response curve measured at 10 and 35 d after heading for the flag leaf, SNU-SG1 exhibited higher initial light conversion efficiency and thus higher gross photosynthetic rate at light saturation compared to HYVs. Light saturation point was not different among genotypes, ranging from 1000 to 1500 ${\mu}mol$ photon $m^{-2}s^{-1}$. Net photosynthetic rate at light saturation($P_{max}$) of the upper four leaves in SNU-SG1 was much higher and sustained longer throughout grain-filling than HYVs and $F_1$ hybrids. The sustained high photosynthetic competence of SNU-SG1 during grain filling was ascribed to the longer maintenance of high mesophyll conductance that resulted from not only high chlorophyll content and its delayed degradation but also the slow degeneration of photosystem II(PS II) as judged by chlorophyll fluorescence($F_v/F_m$) of flag leaves. $F_1$ hybrids showed slow degeneration of photosystem II similar to the male parent SNU-SG1 while chlorophyll degradation pattern close to female parents, thus exhibiting a little higher $P_{max}$ than female parents. These results suggest that SNU-SG1 has a typical functional stay-green trait that can be utilized for increasing rice yield potential through the improved dry matter production during grain filling.

• Journal of Korean Society of Forest Science
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• v.98 no.3
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• pp.331-338
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• 2009

This present study was conducted to investigate photosynthetic characteristics, chlorophyll fluorescence, chlorophyll contents, and growth performances of containerized seedling and bare root seedling of Quercus acutissima growing under different fertilizing schemes. Both of containerized seedling and bare root seedling of Quercus acutissima showed good photosynthetic capacity and apparent quantum yield in the seedlings applied with one gram refining fertilizer (each of N, P, and K is 19%) diluted in one liter water. And chlorophyll contents also showed higher in the seedlings applied with the above fertilization scheme. The seedlings also showed good relative growth performances of root collar diameter, seedling height, total biomass, and leaf area in the some treatment scheme. In most of the treatments, containerized seedlings showed better photosynthetic capacity, apparent quantum yield, chlorophyll contents, and growth performances than bare root seedlings.

• Korean Journal of Medicinal Crop Science
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• v.28 no.1
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• pp.1-8
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• 2020

Background: This study was conducted to investigate the effects of NaCl concentration on the photosynthetic parameters, chlorophyll fluorescence and growth characteristics of Crepidiastrum sonchifolium. Methods and Results: As treatments, we subjected C. sonchifolium plants to four different concentrations of NaCl (0, 50, 100 and 200 mM). We found that the photosynthetic parameters maximum photosynthesis rate (P_{N max}), net apparent quantum yield (Φ), maximum carboxylation rate (V_cmax), and maximum electron transport rate (J_max) were significantly reduced at an NaCl concentration greater than 100 mM. In contrast, there was an increase in water-use efficiency with increasing NaCl concentration, although in terms of growth performances, leaf dry weight, root dry weight, stem length, and total dry weight all decreased with increasing NaCl concentration. Furthermore, leakage of electrolytes, as a consequence of cell membrane damage, clearly increased in response to an increase in NaCl concentration. Analysis of the polyphasic elevation of chlorophyll a fluorescence transients (OKJIP) revealed marked decrease in flux ratios (Φ_PO, Ψ_O and Φ_EO) and the PI_abs, performance index in response to treatment with 200 mM NaCl, thereby reflectings the relatively reduced state of photosystem II. This increase in fluorescence could be due to a reduction in electron transport beyond Q^-_A. We thus found that the photosynthetic parameters, chlorophyll fluorescence and growth characteristics of C. sonchifolium significantly increased in response to treatment with 200 mM NaCl. Conclusions: Collectively, the findings of this study indicate that C. sonchifolium shows relatively low sensitivity to NaCl stress, although photosynthetic activity was markedly reduced in plants exposed to 200 mM NaCl.