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111. 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

112. Effects of rhizobia inoculation and nitrogen fertilization on photosynthetic physiology of soybean

Creator:
Zhou, X.-J., Liang, Y., Chen, H., Shen, S.-H., and Jing, Y.-X.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
biological nitrogen fixation, biomass, carboxylation efficiency, carotenoids, chlorophyll fluorescence, Glycine max, intercellular CO2 concentration, leaf area, stomatal conductance, and quantum yield
Language:
Multiple languages
Description:
Plant growth, contents of photosynthetic pigments, photosynthetic gas exchange, and chlorophyll (Chl) fluorescence in soybean [Glycine max (L.) Merr. cv. Heinong37] were investigated after it was inoculated with Sinorhizobium fredii USDA191 or treated with 5 mM (NH4)2SO4 (N5) and 30 mM (NH4)2SO4 (N30), respectively. In the plants following N5 fertilization, not only plant biomass, leaf area, and Chl content, but also net photosynthetic rate (PN), stomatal conductance (gs), carboxylation efficiency (CE), maximum photochemical efficiency (Fv/Fm) of photosystem 2 (PS2), and quantum yield of PS2 (ΦPS2) were markedly improved as compared with the control plants. There were also positive effects on plant growth and plant photosynthesis after rhizobia inoculation, but the effects were much less than those of N5 fertilization. For N30 plants there were no significant positive effects on plant growth and photosynthetic capacity. Plant biomass, PN, and gs were similar to those of N-limited (control) plants. ΦPS2 and photochemical quenching (qP) were obviously declined while content of carotenoids and non-photochemical quenching (qN) were significantly enhanced in N30 treated plants. This indicated that excess N supply may cause some negative effects on soybean plants. and X.-J. Zhou ... [et al.].
Rights:
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113. Effects of salinity on chlorophyll fluorescence and photosynthesis of barley (Hordeum vulgare L.) grown under a triple-line-source sprinkler system in the field

Creator:
Belkhodja, R., Morales, F., Abadía, A., Medrano, H., and Abadía, J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, cultivar differences, photosystem 2 efficiency, stomatal conductance and frequency, and transpiration rate
Language:
Multiple languages
Description:
In flag leaves of four cultivars of barley (Hordeum vulgare L.) grown in the field under a triple-line-source sprinkler system, that produces a linear soil salinity gradient, a decrease in net carbon dioxide assimilation rate (PN) and stomatal conductance for water vapour (gs) was found. These changes were related to salinity tolerance at moderate salinity. With increasing salinity, PN was saturated at low irradiances and stomatal frequencies increased. A decrease in photosystem 2 (PS2) efficiency was not found in the field after dark adaptation even at high salinity. Salinity induced only small decreases in the actual PS2 efficiency at midday steady-state photosynthesis, indicating that the photosynthetic electron transport was little affected by salinity. Therefore, using PS2 efficiency estimates in attached leaves is probably not a useful tool to screen barley genotypes grown under saline conditions in the field for salinity tolerance. In contrast, excised flag leaves from high salinity plots, once in the laboratory, exhibited a decrease in the variable to maximum chlorophyll fluorescence ratio as compared to excised leaves from control plants. On the other hand, the PN rate might allow for a good discrimination between tolerant and non-tolerant cultivars. and R. Belkhodja ... [et al.].
Rights:
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114. Effects of salt stress on photosynthesis, PSII photochemistry and thermal energy dissipation in leaves of two corn (Zea mays L.) varieties

Creator:
Hichem, H., El Naceur, A., and Mounir, D.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, photosynthesis, ion accumulation, salinity, and Zea mays L.
Language:
Multiple languages
Description:
The effect of four different NaCl concentrations (from 0 to 102 mM NaCl) on seedlings leaves of two corn (Zea mays L.) varieties (Aristo and Arper) was investigated through chlorophyll (Chl) a fluorescence parameters, photosynthesis, stomatal conductance, photosynthetic pigments concentration, tissue hydration and ionic accumulation. Salinity treatments showed a decrease in maximal efficiency of PSII photochemistry (Fv/Fm) in dark-adapted leaves. Moreover, the actual PSII efficiency (ϕPSII), photochemical quenching coefficient (qp), proportion of PSII centers effectively reoxidized, and the fraction of light used in PSII photochemistry (%P) were also dropped with increasing salinity in light-adapted leaves. Reductions in these parameters were greater in Aristo than in Arper. The tissue hydration decreased in salt-treated leaves as did the photosynthesis, stomatal conductance (g s) and photosynthetic pigments concentration essentially at 68 and 102 mM NaCl. In both varieties the reduction of photosynthesis was mainly due to stomatal closure and partially to PSII photoinhibition. The differences between the two varieties indicate that Aristo was more susceptible to salt-stress damage than Arper which revealed a moderate regulation of the leaf ionic accumulation. and H. Hichem, A. El Naceur, D. Mounir.
Rights:
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115. 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:
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116. Effects of supplementary potassium nitrate on growth and gas-exchange characteristics of salt-stressed citrus seedlings

Creator:
Khoshbakht, D., Ghorbani, A., Baninasab, B., Naseri, L. A., and Mirzaei, M.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, dusík, citrusy, photosynthesis, nitrogen, citruses, chlorophyll fluorescence, mineral nutrition, net gas exchange, rootstocks, salinity, salt stress, potassium nitrate, 2, and 581
Language:
Multiple languages
Description:
We investigated the effects of supplementary KNO3 and NaCl on one-year-old, potted Valencia orange (Citrus sinensis) scions grafted on Iranian mandarin Bakraii [Citrus reticulate × Citrus limetta] (Valencia/Bakraii) and Carrizo citrange [C. sinensis × Poncirus trifoliata] (Valencia/Carrizo) rootstocks. After watering plants for 60 days with 50 mM NaCl, the lowest reduction in dry mass, stomatal conductance, and chlorophyll (Chl) content was found in Valencia/Bakraii. Bakraii accumulated more Cl- and Na+ in roots and transferred less to Valencia leaves compared with Carrizo rootstock. Moreover, higher net photosynthetic rate was found in Valencia/Bakraii than those on Carrizo rootstock. NaCl caused a decrease in the maximal efficiency of PSII photochemistry (Fv/Fm) and effective quantum yield (ΦPSII) but elevated coefficient of nonphotochemical quenching. Salinity reduced Ca2+, Mg2+, and total N contents, and increased Na+/K+ ratio in leaves and roots of both grafting combinations. Salinity increased K+ and proline content in leaves and decreased K+ concentrations in roots of both grafting combinations. In salinized plants, nitrate supplementation (10 mM KNO3) reduced leaf abscission, Cl-, Na+, Na+/K+, and Ca2+ concentrations in leaves and roots of both combinations. K+ and N concentrations and proline increased in leaves of the nitrate-supplemented salinized plants. Supplementary nitrate increased leaf number and area, stem elongation, Chl content, Fv/Fm, and ΦPSII and stimulated photosynthetic activity. Thus, nitrate ameliorated the deleterious effects of NaCl stress and stimulated the plant metabolism and growth. It can be used as a vital treatment under such condition., D. Khoshbakht, A. Ghorbani, B. Baninasab, L. A. Naseri, M. Mirzaei., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

117. Effects of thallus temperature and hydration on photosynthetic parameters of Cetraria islandica from contrasting habitats

Creator:
Hájek, J., Barták, M., and Gloser, J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, Cladonia rangiferina, high and low attitude, high and low temperature, iceland moss, irradiance response curves, lichens, Pseudevernia furfuracea, and shade acclimation
Language:
Multiple languages
Description:
Two methods of induced in vivo chlorophyll (Chl) fluorescence were used to investigate the effects of varying thallus temperature and hydration on the performance of photosynthetic apparatus of a foliar lichen Cetraria islandica: slow Chl fluorescence induction kinetic with the analysis of quenching mechanisms, and rapid irradiance response curves of photosynthesis derived from quantum yield of photochemical reactions of photosystem 2 (Φ2) recorded at increasing irradiances. We compared responses of photosynthetic apparatus in populations of C. islandica growing in lower altitude (LAP: 1 350 m a.s.l.) and in higher altitude (HAP: 2 000 m a.s.l.). At each altitude, the samples were collected both in fully irradiated sites (HI) and in shade (LI). Temperature optimum of photosynthetic processes was the same for LAP and HAP thalli of LI populations (18 °C), while it was significantly lower for HI HAP (14 °C). Gradual dehydration of fully hydrated thalli led to initial increase (up to 20 % of water saturation deficit, WSD) in FV/FM and Φ2, no change at 20-50 % WSD, and a dramatic decrease of the parameters within 50-80 % of WSD. LI HAP of C. islandica was the best adapted population to low temperature having higher rates of photochemical processes of photosynthesis than HI HAP within temperature range of -5 to +5 °C. The differences between populations were apparent also in Chl content and thallus morphology. and J. Hájek, M. Barták, J. Gloser.
Rights:
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118. 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:
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119. Effects of water stress on photosynthesis and nitrogen metabolism in vegetative and reproductive shoots of Leymus chinensis

Creator:
Xu, Z. Z. and Zhou, G. S.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll fluorescence, endopeptidase, glutamate dehydrogenase, glutamine synthetase, lipid peroxidation, nitrate reductase, and soil moisture
Language:
Multiple languages
Description:
In Leymus chinensis, mild water stress (soil moisture 60-65 % of field capacity) had no significant effects on nitrogen metabolism, photosynthesis, and chlorophyll fluorescence. Severe water stress (35-40 %) significantly decreased the activities of nitrate reductase, glutamine synthetase, and glutamate dehydrogenase, net photosynthetic rate, stomatal conductance, transpiration rate, maximal efficiency of photosystem 2 photochemistry (Fv/Fm), actual quantum yield, and photochemical quenching, but increased the endopeptidase activity and malondialdehyde contents. The adverse effects on photosynthesis and N metabolism were markedly greater in reproductive shoots than in vegetative shoots. and Z. Z. Xu, G. S. Zhou.
Rights:
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120. Elevated CO2 increased photosynthesis and yield without decreasing stomatal conductance in broomcorn millet

Creator:
Hao, X. Y., Li, P., Li, H. Y., Zong, Y. Z., Zhang, B., Zhao, J. Z., and Han, Y. H.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fluorescence chlorofylu, výměna plynu, obohacování o CO2, efektivita využívání vody, proso seté, chlorophyll fluorescence, CO2 enrichment, gas exchange, water-use efficiency, 2, and 581
Language:
Multiple languages
Description:
Broomcorn millet (Panicum miliaceum L.) is one of the important C4 crops in the semiarid regions of northern China. It is a close relative of biofuel crop switchgrass. Yet, there is no information on how these crops might respond to a climate change in China. In order to gain insight into such a response, we studied the effect of elevated CO2 concentration (EC) on broomcorn millet. The changes in leaf photosynthesis, chlorophyll fluorescence, morphological parameters, biomass and yield in response to EC [i.e., + 200 µmol(CO2) mol-1] over two years were determined at the open-top chamber (OTC) experimental facility in north China. EC increased net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, instantaneous transpiration efficiency, effective quantum yield of PSII photochemistry, and photochemical quenching coefficient of fully expanded flag leaves. Maximal quantum yield of PSII photochemistry declined under EC in 2013, but was not affected in 2014. EC significantly decreased intrinsic efficiency of PSII in 2013, but increased in 2014. Leaf nonphotochemical quenching decreased under EC both in 2013 and 2014. EC significantly enhanced the aboveground biomass and yield by average of 31.4 and 25.5% in both years, respectively. The increased yield of broomcorn millet under EC occurred due to the enhanced number of grains per plant. We concluded that photosynthesis of broomcorn millets was improved through increased stomatal conductance in leaves under EC, which led to an increase in height, stem diameter, aboveground biomass, and yield. This study extends our understanding of the response of this ancient C4 crop to elevated CO2 concentration., X. Y. Hao, P. Li, H. Y. Li, Y. Z. Zong, B. Zhang, J. Z. Zhao, Y. H. Han., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public