Number of results to display per page
Search Results
802. Effects of excess cadmium in soil on JIP-test parameters, hydrogen peroxide content and antioxidant activity in two maize inbreds and their hybrid
- Creator:
- Franić, M., Galić, V., Mazur, M., and Šimić, D.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, antioxidační enzymy, toxicita těžkých kovů, JIP test, fotosystém II, antioxidant enzymes, heavy metal toxicity, photosystem II, 2, and 581
- Language:
- Multiple languages
- Description:
- Excessive cadmium (Cd) content in soil leads to a number of phytotoxic effects and challenges agricultural production. Aim of this study was to investigate different responses of two maize inbreds and their hybrid to an elevated Cd content in soil by measuring photosynthetic and biochemical activity and to identify a Cd tolerance mechanism. Antioxidant statusrelated parameters varied significantly between inbreds and treatments. Dry mass increased in both inbreds, but remained unchanged in hybrid. After the Cd treatment, parameters of chlorophyll a fluorescence varied between inbreds and hybrid performance was similar to inbred B84. We concluded that inbred B84 is Cd-sensitive compared to Os6-2, which did not appear to be negatively affected by Cd treatment at this growth stage studied. We suspect that due to a dilution effect in the hybrid, there was no or very weak Cd stress detected by biochemical parameters, although stress was detected by chlorophyll a fluorescence., M. Franić, V. Galić, M. Mazur, D. Šimić., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
803. Effects of exogenous calcium on mesophyll cell ultrastructure, gas exchange, and photosystem II in tobacco (Nicotiana tabacum Linn.) under drought stress
- Creator:
- Hu, W., Tian, S. B., Di, Q., Duan, S. H., and Dai, K.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- listová hnojiva, chlorofyl, fluorescence, foliar fertilizers, chlorophyll, abiotic stress, chlorophyll a fluorescence, electron transport rate, 2, and 581
- Language:
- Multiple languages
- Description:
- The effects of calcium chloride solution (10 mmol L-1) on mesophyll cell ultrastructure, gas exchange, chlorophyll and carotenoid content, and PSII in tobacco leaf were studied by simulating water deficit conditions via treatment with 25% PEG-6000 for 24 h. The results showed that under drought stress, the mesophyll cell structure and morphology were destroyed, photosynthesis and gas-exchange processes changed, photosynthetic pigment content decreased, and the electron transfer efficiency in PSII reduced. However, compared with the control treatment, under drought conditions, the addition of exogenous calcium could stabilize the structure and function of the chloroplasts, mitochondria, and endomembrane system in the mesophyll cells, maintain normal leaf net photosynthetic rate and gas exchange, alleviate the degree of photosynthetic pigment degradation, and increase the electron transfer energy in the leaves in PSII. As a means of ensuring normal photosynthesis under drought stress, we discovered that the application of exogenous calcium was more important for stabilization of the structure of the organelles, regulation of the osmotic balance, and increase of the photosynthetic pigment content, and proved to be less important for regulation of stomatal opening and closing., W. Hu, S. B. Tian, Q. Di, S. H. Duan, K. Dai., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
804. Effects of exogenous hormones on leaf photosynthesis of Panax ginseng
- Creator:
- Li, X. and Xu, K.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, ženšen, photosynthesis, ginseng, absorbed water mass, shade plant, exogenous hormones, Panax ginseng, 2, and 581
- Language:
- Multiple languages
- Description:
- Ginseng (Panax ginseng) is a typical perennial shade plant. Aim of this study was to investigate the effects of exogenous hormones on photosynthesis of P. ginseng. At different growth stages, the aerial parts of P. ginseng plants were cut at the stem base and they were inserted into the nutrient solutions containing different exogenous hormones. Then the leaf photosynthesis and water absorbing capacity (absorbing water mass) of the excised plants were measured. The results showed that exogenous abscisic acid (ABA) decreased significantly net photosynthetic rate (PN), stomatal conductance, transpiration rate, and absorbed water mass of excised P. ginseng at all growth stages, while both cytokinin (CTK) and indole-3-acetic acid (IAA) enhanced those parameters. Comparing different growth stages, ABA caused more severe inhibition of leaf photosynthesis at the early growth stage, while CTK and IAA showed significant enhancement of leaf photosynthesis at later growth stage. ABA reduced highly intercellular CO2 concentration of P. ginseng at the flowering and green fruit stages, but it had only a small effect at red fruit early and red fruit stages. During the early growth stage, the inhibitory effect of ABA on leaf PN might be caused mainly due to the stomatal limitation. However, the reason for this reduction was complex at the later growth stage and it included stomatal and other factors., X. Li, K. Xu., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
805. Effects of exogenous nitric oxide on photosynthesis
- Creator:
- Procházková, D., Haisel, D., Wilhelmová, Naďa, Pavlíková, Daniela, and Száková, Jiřina
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll fluorescence, chloroplast, nitration, nitrotyrosine, 2, and 581
- Language:
- Multiple languages
- Description:
- Nitric oxide (NO) is an important signalling molecule with diverse physiological functions in plants. In plant cell, it is synthesised in several metabolic ways either enzymatically or nonenzymatically. Due to its high reactivity, it could be also cytotoxic in dependence on concentration. Such effects could be also mediated by NO-derived compounds. However, the role of NO in photosynthetic apparatus arrangement and in photosynthetic performance is poorly understood as indicated by a number of studies in this field with often conflicting results. This review brings a short survey of the role of exogenous NO in photosynthesis under physiological and stressful conditions, particularly of its effect on parameters of chlorophyll fluorescence. and D. Procházková ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
806. Effects of exogenous phenolic acids on photosystem functions and photosynthetic electron transport rate in strawberry leaves
- Creator:
- Lu, X. F., Zhang, H., Lyu, S. S., Du, G. D., Wang, X. Q., Wu, C. H., and Lyu, D. G.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- jahodník, Fragaria, chlorofylová fluorescence, výměna plynu, fenolová kyselina, chlorophyll fluorescence, gas exchange, phenolic acid, 2, and 581
- Language:
- Multiple languages
- Description:
- Our study investigated the physiological and biochemical basis for the effects of exogenous phenolic acids on the function of the photosynthetic apparatus and photosynthetic electron transport rate in strawberry seedlings. Potted seedlings of the strawberry (Fragaria × ananassa Duch.) were used. Syringic acid inhibited net photosynthetic rate and water-use efficiency decreased. Additionally, primary quinone electron acceptor of the PSII reaction centre, the PSII reaction centre and the oxygen evolving complex were also impaired. Both the maximum quantum yield of the PSII primary photochemistry and the performance index on absorption basis were depressed, resulting in reduced function of the photosynthetic electron transport chain. Otherwise, low phthalic acid concentrations enhanced photosynthetic capacity, while high concentrations showed opposite effects. Syringic acid exhibited a higher toxic effect than that of phthalic acid which was more evident at higher concentrations., X. F. Lu, H. Zhang, S. S. Lyu, G. D. Du, X. Q. Wang, C. H. Wu, D. G. Lyu., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
807. Effects of exposure in space on tomato seeds: Photosynthesis, biomass, and water relations of well-watered and drought-stressed plants
- Creator:
- Marmor, M. S. and Martin, C. E.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- cosmic radiation, internal CO2 concentration, microgravity, net CO2 exchange, osmotic potential, stomatal conductance, and water potential
- Language:
- Multiple languages
- Description:
- Tomato seeds exposed to space conditions for nearly six years on board the Long Duration Exposure Facility (LDEF) satellite were subsequently germinated and the resultant seedlings grown on earth under controlled conditions for analysis. Photosynthesis, biomass, and water relations were compared between mature plants grown from earth-based control seeds and space-exposed seeds under both well-watered and drought-stressed conditions. No consistent significant differences in photosynthesis and water relations were observed in the two sets of plants at any level of drought stress. Fruit production, however, though limited and variable, was significantly greater in plants grown from space-exposed seeds than in plants grown from earth-based seeds. Overall, exposure of seeds to space had only minor effects on the physiology and growth of plants grown from such seed. and M. S. Marmor, C. E. Martin.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
808. Effects of fertilization on leaf photosynthetic characteristics and grain yield in tartary buckwheat Yunqiao1
- Creator:
- Wang, C., She, H. Z., Liu, X. B., Hu, D., Ruan, R. W., Shao, M. B., Zhang, L. Y., Zhou, L. B., Zhang, G. B., Wu, D. Q., and Yi, Z. L.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorofyl, chlorophyll, hnojiva, index listové plochy, rychlost čisté fotosyntézy, produktivita, výnos zrna, pohanka, fertilizers, leaf area index, net photosynthetic rate, productivity, grain yield, buckwheat, 2, and 581
- Language:
- Multiple languages
- Description:
- Tartary buckwheat (Fagopyrum tataricum Gaertn) has been praised as one of green foods for humans in the 21st century. Effects of fertilization on leaf photosynthetic characteristics and grain yield of tartary buckwheat has not been yet reported in detail. Our experiment was set as a split-plot factorial. The main plots and subplots were designed by fertilizer ratio and rate as: NPK 1:1:1 (A1), NPK 1:4:2 (A2), NPK 1:2:3 (A3), and 300 (B1), 450 (B2), and 600 (B3) kg (NPK) ha-1. Our results showed that the grain yield was significantly and positively correlated with the net photosynthetic rate (PN), stomatal conductance (gs), transpiration rate (E), PAR, stomatal limitation value (Ls), chlorophyll content (SPAD value), and leaf area index (LAI), while significantly and negatively correlated with intercellular CO2 concentration (Ci) and water-use efficiency (WUE). The grain yield, PN, gs, E, PAR, Ls, SPAD, and LAI increased and then decreased with enhanced fertilization, and their maximum values appeared in the A2B2 treatment. The Ci and WUE decreased and then increased with enhanced fertilization, and their minimum values appeared in the A2B2 treatment. Our results suggested that fertilization had significant effects on the leaf photosynthetic capacity and grain yield of tartary buckwheat Yunqiao1, and the best fertilization strategy was 450 kg ha-1 with NPK 1:4:2., C. Wang, H. Z. She, X. B. Liu, D. Hu, R. W. Ruan, M. B. Shao, L. Y. Zhang, L. B. Zhou, G. B. Zhang, D. Q. Wu, Z. L. Yi., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
809. Effects of fertilization on the growth, photosynthesis, and biomass accumulation in juvenile plants of three coffee (Coffea arabica L.) cultivars
- Creator:
- Zhang, Z. X., Cai, Z. Q., Liu, G. Z., Wang, H., Huang, L., and Cai, C. T.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- biomasa, fotosyntéza, biomass, photosynthesis, fertilizace, efektivita využívání vody, kávovník arabský, fertilization, relative growth rate, water-use efficiency, Coffea arabica, 2, and 581
- Language:
- Multiple languages
- Description:
- We carried out a field experiment in order to study effects of fertilization in juvenile plants of three coffee (Coffea arabica) cultivars in Yunnan, SW China. Fertilization treatments included a control without fertilizer (CK), combinations of three NPK fertilization rates [high fertilization (FH), medium fertilization (FM), and low fertilization (FL) with 135, 90, and 45 g per plant per year, respectively], and at two N:P2O5:K2O ratios (R1, 1:0.5:0.8; R2, 1:0.8:0.5). The growth in juvenile plants was not altered by fertilization, with two clear growth peaks being observed in both the height and stem growth rates (RGRs) throughout a year. Both FM and FH resulted in significantly higher RGRs in both height and stem diameter compared to FL and CK in all three cultivars. At the same fertilization rate, the leaf area, branch number, longest branch length, internode number, and biomass of R2 were higher than those of R1, and P significantly affected the root biomass and root to shoot ratio. Compared to the FL treatment, both FM and FH treatments resulted in higher net photosynthetic rates and stomatal conductance across seasons, and in higher intrinsic water-use efficiency during the dry season and at the middle of the wet season. Photosynthetic nitrogen-use efficiency at R2 was higher than that at R1, but no significant differences were observed between the different fertilization rates. Among the three coffee cultivars, Caturra exhibited the highest height, stem diameter, longest branch length, and internode number. Our results indicated that the optimal N:P2O5:K2O ratio was 1:0.8:0.5 for the juvenile growth of coffee plants. Both FM and FH could help optimize the growth and photosynthetic rate of coffee plants, but FM is suitable for the ecological friendly agriculture and economic sustainability at coffee plantations., Z. X. Zhang, Z. Q. Cai, G. Z. Liu, H. Wang, L. Huang, C. T. Cai., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
810. Effects of flooding on susceptibility of Taxodium distichum L. seedlings to drought
- Creator:
- Elcan, J. M. and Pezeshki, S. R.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- baldcypress, dry mass, leaf, photosynthesis, redox potential, root, stem, stomatal conductance, transpiration rate, and wetlands
- Language:
- Multiple languages
- Description:
- Responses of baldcypress (Taxodium distichum) seedlings to soil moisture were studied to test the hypothesis that flooding may lead to seedling's higher susceptibility to drought. Treatments included a well-watered but drained control (C), continuously flooded (CF), control followed by drought (CD), and flooded followed by drought (FD). Gas exchange values revealed no significant effects on net photosynthetic rate (PN) in response to flooding. In contrast, after the onset of drought, PN was significantly reduced in CD and FD plants. Significant growth reductions under mild drought conditions indicated that baldcypress seedlings were drought sensitive. However, comparison of gas exchange rates and growth responses between CD and FD plants indicated that prior flooding had no detectable effect on subsequent sensitivity of baldcypress to drought. These findings explain baldcypress persistence in wetland habitats characterized by periodic flooding and mild drought. and J. M. Elcan, S. R. Pezeshki.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public