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82. Effects of ozone fumigation on photosynthesis and membrane permeability in leaves of spring barley, meadow fescue, and winter rape
- Creator:
- Plażek, A., Rapacz, M., and Skoczowski, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Brassica napus var. oleifera, chlorophyll fluorescence, electrolyte leakage, Festuca pratensis, Hordeum vulgare, net photosynthetic rate, ozone, and stomatal conductance
- Language:
- Multiple languages
- Description:
- Seedlings of spring barley, meadow fescue, and winter rape were fumigated with 180 μg kg-1 of ozone for 12 d, and effect of O3 on photosynthesis and cell membrane permeability of fumigated plants was determined. Electrolyte leakage and chlorophyll fluorescence were measured after 6, 9, and 12 d of fumigation, while net photosynthetic rate (PN) and stomatal conductance (gs) were measured 9 d after the start of ozone exposure. O3 treatment did not change membrane permeability in fescue and barley leaves, while in rape a significant decrease in ion leakage was noted within the whole experiment. O3 did not change the photochemical efficiency of photosystem 2 (PS2), i.e., Fv/Fm, and the initial fluorescence (F0). The values of half-rise time (t1/2) from F0 to maximal fluorescence (Fm) decreased in fescue and barley after 6 and 9 d of fumigation. PN decreased significantly in ozonated plants, in the three species. The greatest decrease in PN was observed in ozonated barley plants (17 % of the control). The ozone-induced decrease in PN was due to the closure of stomata. Rape was more resistant to ozone than fescue or barley. Apparently, the rape plants show a large adaptation to ozone and prevent loss of membrane integrity leading to ion leakage. and A. Plażek, M. Rapacz. A. Skoczowski.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
83. Effects of potato virus YNTN infection on gas exchange and photosystem 2 function in leaves of Solanum tuberosum L.
- Creator:
- Zhou, Y. H., Peng, Y. H., Lei, J. L., Zou, L. Y., Zheng, J. H., and Yu, J. Q.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, intercellular CO2 concentration, net photosynthetic rate, photochemistry, photosynthetic electron transport, potato, potato virus Y, quantum yield, and stomatal conductance
- Language:
- Multiple languages
- Description:
- Photosynthetic responses of potato (Solanum tuberosum L. cv. Chunzao) were examined during potato virus Y (PVYNTN) infection. PVYNTN infection significantly reduced net photosynthetic rate and stomatal conductance, but had little influence on intercellular CO2 concentration. As the disease developed, the maximum carboxylation velocity of ribulose-1,5-bisphosphate carboxylase/oxygenase and the maximum electron transport rate contributing to ribulose-1,5-bisphosphate regeneration gradually decreased, followed by substantial reductions in the relative quantum efficiency of photosystem 2 (PS2) electron transport, the efficiency of excitation energy capture by open PS2 reaction centres, and photochemical quenching, but not in sustained photoinhibition. Thus PVYNTN depressed photosynthesis mainly by interfering with the enzymatic processes in the Calvin cycle which resulted in a down-regulation of electron transport. and Y. H. Zhou ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
84. Effects of reddening of cotton (Gossypium hirsutum L.) leaves on functional activity of photosynthetic apparatus
- Creator:
- Velikova, V., Tsonev, T., Edreva, A., Gürel, A., and Hakerlerler, H.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, net photosynthetic rate, stomatal conductance, transpiration rate, and water use efficiency
- Language:
- Multiple languages
- Description:
- Strong inhibition of rates of CO2 assimilation and transpiration, stomatal conductance, and water use efficiency as well as photosystem 2 (PS2) photochemical activity were related to the severity of reddening. The inhibition of photosynthesis in red cotton leaves was due to both decreased photochemical activity and stomatal limitation. Lowered photosynthetic capacity could be one of the main factors of reduced yield in reddening cotton. and V. Velikova ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
85. Effects of reduced irradiance on leaf morphology, photosynthetic capacity, and fruit yield in olive (Olea europaea L.)
- Creator:
- Gregoriou, K., Pontikis, K., and Vemmos, S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- areal leaf mass, chlorophyll, chloroplasts, fruit yield, leaf anatomy, net photosynthetic rate, shade, stomata, and trichomes
- Language:
- Multiple languages
- Description:
- One-year-old olive trees (cv. Koroneiki) were grown in plastic containers of 50 000 cm3 under full daylight and 30, 60, and 90 % shade for two years. The effects of shade on leaf morphology and anatomy, including stomatal density and chloroplast structure, net photosynthetic rate (PN), stomatal conductance (gs), and fruit yield were studied. Shade reduced leaf thickness due to the presence of only 1-2 palisade layers and reduced the length of palisade cells and spongy parenchyma. The number of thylakoids in grana as well as in stroma increased as shade increased, while the number of plastoglobuli decreased in proportion to the reduced photosynthetically active radiation (PAR). The higher the level of shade, the lower the stomatal and trichome density, leaf mass per area (ALM), gs, and PN. Shade of 30, 60, and 90 % reduced stomatal density by 7, 16, and 27 %, respectively, while the corresponding reduction in PN was 21, 35, and 67 %. In contrast, chlorophyll a+b per fresh mass, and leaf width, length, and particularly area increased under the same shade levels (by 16, 33, and 81 % in leaf area). PN reduction was due both to a decrease in PAR and to the morphological changes in leaves. The effect of shade was more severe on fruit yield per tree (32, 67, and 84 %) than on PN indicating an effect on bud differentiation and fruit set. The olive tree adapts well to shade compared with other fruit trees by a small reduction in stomatal and trichome density, palisade parenchyma, and a significant increase in leaf area. and K. Gregoriou, K. Pontikis, S. Vemmos.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
86. Effects of shoot girdling on photosynthetic capacity, leaf carbohydrate, and bud abscission in pistachio (Pistacia vera L.)
- Creator:
- Vemmos, S. N., Papagiannopoulou, A., and Coward, S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- biologie, biology, areal leaf mass, biennial bearing, chlorophyll, net photosynthetic rate, nitrogen, starch, stomatal conductance, sugars, 2, and 57/59
- Language:
- Multiple languages
- Description:
- The effects of shoot girdling on stomatal conductance (gs), leaf photosynthesis (PN), concentrations of carbohydrates, nitrogen and chlorophyll (Chl) in leaves, areal leaf mass (ALM), the diameter and length of shoots, and bud abscission in pistachio were investigated. Girdling individual shoots at the base of the current year’s shoot (girdle I), separating inflorescent buds on the terminal current year’s shoot from the developing fruits on the previous year’s shoot, reduced inflorescent bud abscission by 70% in comparison to nongirdled controls. Girdle I significantly reduced concentrations of nitrogen in leaves but increased those of nonstructural carbohydrates particularly of starch. Shoot diameter increased by 13.1% and 26.4% at 33 and 81 days after girdling (DAG), respectively, compared to 1% and 3.4% in the control, respectively. Both the leaf dry mass/fresh mass ratio and ALM were increased significantly by girdle I from 12 DAG. The concentrations of Chl a, Chl b, Chl (a+b), as well as the ratio of Chl a/b, all decreased with girdle I. The greatest negative effect of girdle I was on gs and PN. PN was reduced by 55% of its initial value and was 44% less than in the control leaves at 10 DAG, and fell to approximately 30% that of the control from 21 DAG. In contrast, girdling at the base of one-year-old shoots (girdle II), thus not separating fruits from the inflorescent buds, did not significantly affect gs or PN. The effect of girdling on PN and the possible factors that are involved in the reduction of photosynthesis in pistachio are discussed., S. N. Vemmos, A. Papagiannopoulou, S. Coward., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
87. Effects of simulated acid precipitation on photosynthesis, chlorophyll fluorescence, and antioxidative enzymes in Cucumis sativus L.
- Creator:
- Yu, Jiang-Quan, Ye, Su-Feng, and Huang, Li-Feng
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- acid rain, catalase, chlorophyll fluorescence, guaiacol peroxidase, lipid peroxidation, malonyldialdehyde, net photosynthetic rate, photosystem 2, and superoxide dismutase
- Language:
- Multiple languages
- Description:
- The effects of simulated acid rain on gas exchange, chlorophyll fluorescence, and anti-oxidative enzyme activity in cucumber seedlings (Cucumis sativus L. cv. Jingchun No. 4) were investigated. Acid rain significantly reduced net photosynthetic rate and mainly non-stomatal factors contributed to the decrease of photosynthesis during the experimental period. The reduced photosynthesis was associated with a decreased maximal photochemical efficiency (Fv/Fm) and the average quantum yield of the photosystem 2 (PS2) reaction centres (ΦPS2). Meanwhile, acid rain significantly increased the activities of guaiacol peroxidase (GPX) and superoxide dismutase (SOD), but decreased the activity of catalase (CAT) together with an increased content of malonyldialdehyde (MDA), Hence the changes in photosynthesis in acid rain treatment might be a secondary effect of acidity damage probably due to lipid peroxidation of lipids and proteins in thylakoid membrane rather than direct effect on PS2 reaction centre. and Jing-Quan Yu, Su-Feng Ye, Li-Feng Huang.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
88. Effects of sodium chloride stress on gas exchange, chlorophyll content and nutrient concentrations of nine citrus rootstocks
- Creator:
- Khoshbakht, D., Ramin, A. A., and Baninasab, B.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, Írán, Iran, growth analysis, mineral nutrition, net photosynthetic rate, salinity, 2, and 581
- Language:
- Multiple languages
- Description:
- a1_We investigated the influence of salinity (0, 25, 50, or 75 mM NaCl) on gas exchange and physiological characteristics of nine citrus rootstocks (Cleopatra mandarin, Carrizo citrange, Macrophylla, Iranian mandarin Bakraii, Rangpur lime, Rough lemon, Sour orange, Swingle citrumelo, and Trifoliate orange) in a greenhouse experiment. Total plant dry mass, total chlorophyll (Chl) content, and gas-exchange variables, such as net photosynthetic rate (PN), stomatal conductance (g s), intercellular CO2 concentration, were negatively affected by salinity. In addition, ion concentrations of Cl- and Na+ increased by salinity treatments. Salinity also increased Mg2+ content in roots and reduced Ca2+ and Mg2+ concentrations in leaves. The K+ concentration in leaves was enhanced at low salinity (25 mM NaCl), whereas it decreased with increasing salinity stress. Salinity caused a decline in K+ contents in roots., a2_The rootstocks showed major differences in the extent of Cl- and Na+ accumulation in leaves and in their ability to maintain the internal concentrations of essential nutrients in response to different salinity. Therefore, in addition to inhibitory effects of high concentrations of Cl- and Na+, an imbalance of essential nutrients may also contribute to the reduction in gas exchange under saline conditions. Higher tolerance of rootstocks to salinity could be associated with the reduction of Cl- and Na+ uptake and transport to leaves, ability to keep higher Chl, gs, PN, and better maintenance of nutrient uptake even under high salinity. We found that Sour orange and Cleopatra mandarin were the rootstocks most tolerant to salinity of all nine studied. In addition, Trifoliate orange, Carrizo citrange, and Swingle citrumelo were the rootstocks most sensitive to salt stress followed by the Rough lemon and Macrophylla that showed a low-to-moderate tolerance, and Rangpur lime and Bakraii, with a moderate-to-high tolerance to high salinity., D. Khoshbakht, A.A. Ramin, B. Baninasab., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
89. Effects of water stress and nitrogen supply on leaf gas exchange and fluorescence parameters of Sophora davidii seedlings
- Creator:
- Wu, F. Z., Bao, W. K., Li, F. L., and Wu, N.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- adaptation, chlorophyll fluorescence, intercellular CO2 concentration, leaf area, net photosynthetic rate, respiration rate, specific leaf area, stomatal conductance, and water use efficiency
- Language:
- Multiple languages
- Description:
- Two-month-old seedlings of Sophora davidii were subjected to a randomized complete block design with three water (80, 40, and 20 % of water field capacity, i.e. FC80, FC40, and FC20) and three N supply [N0: 0, Nl: 92 and Nh: 184 mg(N) kg-1(soil)] regimes. Water stress produced decreased leaf area (LA) and photosynthetic pigment contents, inhibited photosynthetic efficiency, and induced photodamage in photosystem 2 (PS2), but increased specific leaf area (SLA). The decreased net photosynthetic rate (PN) under medium water stress (FC40) compared to control (FC80) might result from stomatal limitations, but the decreased PN under severe water deficit (FC20) might be attributed to non-stomatal limitations. On the other hand, N supply could improve photosynthetic capacity by increasing LA and photosynthetic pigment contents, and enhancing photosynthetic efficiency under water deficit. Moreover, N supply did a little in alleviating photodamages to PS2 caused by water stress. Hence water stress was the primary limitation in photosynthetic processes of S. davidii seedlings, while the photosynthetic characters of seedlings exhibited positive responses to N supply. Appropriate N supply is recommended to improve photosynthetic efficiency and alleviate photodamage under water stress. and F. Z. Wu ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
90. Elevated CO2 concentration enhances the role of the ear to the flag leaf in determining grain yield of wheat
- Creator:
- Zhu, C.-W., Zhu, J.-G., Liu, G., Zeng, Q., Xie, Z.-B., Pang, J., Feng, Z.-Z., Tang, H.-Y., and Wang, L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- net photosynthetic rate and Triticum aestivum
- Language:
- Multiple languages
- Description:
- Net photosynthetic rate (PN) of ear and flag leaf during grain filling stage and grain yield of plants with non-darkened or darkened flag leaf or darkened ear were examined in two different CO2 concentrations: ambient (AC) and AC+200 µmol mol-1 (EC). Ear showed much higher enhancement (56 %) of PN than flag leaf (23 %) under EC. Moreover, CO2 enrichment shortened the photosynthetic duration of flag leaf relative to ear. In this way the ratio of ear to flag leaf contribution to grain yield increased from 1.18 (AC) to 1.39 (EC). and C.-W. Zhu ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public