Number of results to display per page
Search Results
722. Effect of leaf age and position on light-saturated CO2 assimilation rate, photosynthetic capacity, and stomatal conductance in rubber trees
- Creator:
- Kositsup, B., Kasemsap, P., Thanisawanyangkura, S., Chairungsee, N., Satakhun, D., Teerawatanasuk, K., Ameglio, T., and Thaler, P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, Hevea brasiliensis, leaf whorl, maximum rate of carboxylation, maximum rate of electron transport, nitrogen, photosynthesis, and rubber clone
- Language:
- Multiple languages
- Description:
- Shoots of the tropical latex-producing tree Hevea brasiliensis (rubber tree) grow according to a periodic pattern, producing four to five whorls of leaves per year. All leaves in the same whorl were considered to be in the same leaf-age class, in order to assess the evolution of photosynthesis with leaf age in three clones of rubber trees, in a plantation in eastern Thailand. Light-saturated CO2 assimilation rate (Amax) decreased more with leaf age than did photosynthetic capacity (maximal rate of carboxylation, Vcmax , and maximum rate of electron transport, Jmax), which was estimated by fitting a biochemical photosynthesis model to the CO2-response curves. Nitrogen-use efficiency (Amax/Na, Na is nitrogen content per leaf area) decreased also with leaf age, whereas Jmax and Vcmax did not correlate with Na. Although measurements were performed during the rainy season, the leaf gas exchange parameter that showed the best correlation with Amax was stomatal conductance (gs). An asymptotic function was fitted to the Amax-gs relationship, with R2 = 0.85. Amax, Vcmax, Jmax and gs varied more among different whorls in the same clone than among different clones in the same whorl. We concluded that leaf whorl was an appropriate parameter to characterize leaves for the purpose of modelling canopy photosynthesis in field-grown rubber trees, and that stomatal conductance was the most important variable explaining changes in Amax with leaf age in rubber trees. and B. Kositsup ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
723. Effect of light intensity on the age dependence of nonphotochemical fluorescence quenching in wheat leaf
- Creator:
- Nesterenko, T. V., Shikhov, V. N., and Tikhomirov, A. A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll fluorescence induction, leaf age, photosystem II, 2, and 581
- Language:
- Multiple languages
- Description:
- The effects of actinic light (AL) intensity on the age dependence of nonphotochemical fluorescence quenching (qN) and effective quantum yield in PSII (ΦPSII) were studied in continuously illuminated wheat leaves of the upper tier. Regular changes were revealed in both age dependence of qN at elevated AL intensities and light curves of qN. These changes are related to alterations in strategies of redistribution and use of absorbed light energy by the photosynthetic apparatus at different stages of wheat leaf development. Unlike ΦPSII, qN as a parameter was more sensitive to the differences in the leaf age at a certain range of light intensities. At the same time, the stability of qN at moderate light intensities may serve as an indication of leaf maturity., T. V. Nesterenko, V. N. Shikhov, A. A. Tikhomirov., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
724. Effect of light quality on leaf photosynthetic characteristics and fruit quality of peach (Prunus persica L. Batch)
- Creator:
- Zhang, B.-B., Xu, J.-L., Zhou, M., Yan, D.-H., and Ma, R.-J.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, appearance, internal quality, irradiance spectrum, 2, and 581
- Language:
- Multiple languages
- Description:
- Different light filters affect leaf photosynthetic features and fruit quality. Consequently, selecting the appropriate covering filter for rain-shelter cultivation of peaches is a key part of successful production. We used a late-maturing peach variety ‘Xiahui 8’ to study differences in leaf photosynthetic features, chlorophyll fluorescence characteristics, and fruit quality under neutral, red, yellow, green, and blue filter, with natural light as control. The results showed that the leaf photosynthetic ability and internal quality under the neutral filter treatment were elevated compared with the control, and the appearance color was the same as the control. Leaves under neutral filter could maintain higher photosynthetic ability than other filter treatments. In addition, the fruits could also keep higher quality when treated with neutral filter. Therefore, the application of neutral filter in rain-shelter cultivation of ‘Xinhui 8’ peaches is recommended for maintaining high photosynthetic capacity and for improving fruit quality., B.-B. Zhang, J.-L. Xu, M. Zhou, D.-H. Yan, R.-J. Ma., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
725. Effect of long term exposure to high CO2 concentrations on photosynthetic characteristics of Prunus avium L. plants
- Creator:
- Druţă, A.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, compensation irradiance, dry mass, photochemical efficiency, stomatal conductance, and sweet cherry
- Language:
- Multiple languages
- Description:
- The effect of two elevated carbon dioxide concentrations, 700 µmol(CO2) mol-1 (C700) and 1 400 µmol(CO2) mol-1 (C1400), on photosynthetic performances of 1-year-old Prunus avium L. plant was studied. Plants grown at C700 were characterised by increased net photosynthetic rate (PN) as compared to those grown at C1400. Plant photosynthetic adjustment to C1400 resulted in 27 % higher PN than in control at atmospheric CO2 concentration (Ca) at the beginning of the experiment (3-4 weeks) with a consequent decline to the end of the experiment. Thus, 1 400 µmol(CO2) mol-1 had short-term stimulatory effect on plant PN. Both chlorophyll (Chl) a and b concentrations dramatically decreased during exposure to C1400. Compensation irradiance was increased by 57 % in C700 and by 87 % in C1400. Photochemical efficiency (φ) was affected by balloon environment, however, a clear stimulatory effect of C700 was detected. Opposite influence of both elevated CO2 concentrations on PNmax was established: slight increase by C700 (2.7 % at Ca), but considerable decrease by C1400 (63 % at Ca). Exposure to C700 enhanced compensation irradiance by 42 %, while C1400 by only 21 %. Either C700 or C1400 did not reduce stomatal conductance (gs). Leaf area per plant (LAR) was more stimulated by C700 than by C1400. High unit area leaf mass, specific leaf area, and dry matter accumulation in roots without affecting tissue density characterised plants grown in C1400. However, when considering the root : shoot ratio, these plants allocated less carbon to the roots than plants from other treatments.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
726. Effect of low irradiance on the photosynthetic performance and spiking of Phalaenopsis
- Creator:
- Liu, Y.-C., Liu, C.-H., Lin, Y.-C., Lu, C.-H., Chen, W.-H., and Wang, H.-L.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, CAM, carbohydrate, chlorophyll fluorescence, flower stalk, gas exchange, oxygen evolution, 2, and 581
- Language:
- Multiple languages
- Description:
- Lowering irradiance can delay the flower stalk, i.e., spike development, in order to schedule flowering time of Phalaenopsis; however, the effect on photosynthetic performance and spiking inhibition remains poorly understood. We compared light and shade treatments of Phalaenopsis aphrodite subsp. formosana in order to determine how limiting light affects day-night changes in the photosynthetic capacity of leaves and the carbon pool of leaves and stems resulting in delayed spiking. The low irradiance treatment [20 μmol(photon) m-2 s-1] for six weeks did not affect potential functions of photosynthetic apparatus estimated by chlorophyll a fluorescence analysis, but it significantly reduced the net CO2 uptake and O2 evolution rates, carbohydrate and organic acid concentrations, and amplitudes of CAM activity in new and fully expanded leaves of Phalaenopsis and delayed the spiking compared with the control kept at 150 μmol(photon) m-2 s-1. The shortened stem contained a remarkably high sucrose concentration, accounting for more than 80% of total soluble sugars for both treatments throughout the day. Moreover, the sucrose concentration was unaffected by the lowering of irradiance. The relationship between the sucrose content and spiking seemed to be loose; the major factor(s) for spiking in Phalaenopsis remained to be ascertained as the flower stalk bud is attached to the shortened stem., Y.-C. Liu, C.-H. Liu, Y.-C. Lin, C.-H. Lu, W.-H. Chen, H.-L. Wang., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
727. Effect of melatonin priming on photosynthetic capacity of tomato leaves under low-temperature stress
- Creator:
- Yang, X. L., Xu, H., Li, D., Gao, X., Li, T. L., and Wang, R.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- abiotické faktory, abiotic factors, chemické inicializace, chlorofylová fluorescence, fotoinhibice, chemical priming, chlorophyll fluorescence, photoinhibition, 2, and 581
- Language:
- Multiple languages
- Description:
- Melatonin has different functions in plant growth and development, especially in the protection of plants suffering from various forms of abiotic stress. We explored the effect of melatonin priming on photosynthetic activity of tomato (Lycopersicon esculentum L.) leaves. Our results showed that 100 µM is the optimal concentration used for alleviation of the damage to photosynthetic apparatus. Melatonin priming both in the form of leaf spray and direct root application was found to reduce the damage to photosynthetic apparatus, and increase the electron transfer rate and quantum yield of PSI and PSII photochemistry, to protect the thylakoid membrane from damage caused by low-temperature stress. Our study provides fundamental information for further research on the molecular mechanism of melatonin function in regulating photosynthesis., X. L. Yang, H. Xu, D. Li, X. Gao, T. L. Li, R. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
728. Effect of mycorrhizal inoculation on ecophysiological responses of pistachio plants grown under different water regimes
- Creator:
- Bagheri, V., Shamshiri, M. H., Shirani, H., and Roosta, H. R.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, chlorophyll fluorescence, Mycorrhizae, photosynthesis, pistachio, and water stress
- Language:
- Multiple languages
- Description:
- In a greenhouse experiment, the influence of arbuscular mycorrhizal fungi (Glomus mosseae and Glomus intraradices) and water stress [100% field capacity (FC), 75% FC, 50% FC and 25% FC] on maximal quantum yield of photosystem II (PSII) photochemistry (Fv/Fm) and some other ecophysiological characteristics of two pistachio cultivar (Pistacia vera cv. Badami-Riz-Zarand and Pistacia vera cv. Qazvini) were investigated. No difference was found in colonization rate between the two arbuscular mycorrhizal fungi (AMF) applied. Water stress reduced the mycorrhizal colonization in both cultivars at the same rate but the difference was significant just with severe water stress level (25% FC). The Fv/Fm was also adversely affected by water stress from 75% FC downwards in Qazvini cultivar while in Badami, increase in water-stress intensity had no significant effect on this parameter. Gasexchange parameters were decreased with increasing stress intensity and chlorophyll (Chl) pigments were increased with mild water stress (75% FC) compared with control (100% FC) and then decreased with increasing stress intensity. The carotenoids (Car) content increased significantly in the stressed leaves in all water-stress levels irrespective of AMF treatment and cultivar type. The adverse effects of water stress were significantly reduced by AM inoculation and in the most of measured parameters, both AMF had an equal influence except with the intercellular CO2 concentration (Ci), where G. intraradices was superior. Results obtained from Chl fluorescence probe indicated that inoculated AMF enhanced photochemical efficiency of light reactions of the PSII in intact pistachio leaf tissues both under irrigation and waterstress conditions. Under mild and moderate water stress, mycorrhizal pistachio plants had higher relative Chl and Car content and higher gas-exchange capacity (increased photosynthesis and transpiration rate) but under severe water-stress condition (25% FC), the effects of mycorrhizal treatments were not noticeable. Data obtained in present study emphasized that Qazvini is more tolerant to water stress than Badami because photosynthesis activity in Qazvini was more efficiently protected than in the Badami, as indicated by related parameters. and V. Bagheri ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
729. Effect of NaCl and isoosmotic polyethylene glycol stress on gas exchange in shoots of the C4 xerohalophyte Haloxylon aphyllum (Chenopodiaceae)
- Creator:
- Rakhmankulova, Z. F., Voronin, P. Yu., Shuyskaya, E. V., Kuznetsova, N. A., Zhukovskaya, N. V., and Toderich, K. N.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, oxidace, photosynthesis, oxidation, net photosynthetic rate, osmotic stress, proline, salinity, transpiration, Haloxylon aphyllum, 2, and 581
- Language:
- Multiple languages
- Description:
- The effects of NaCl (200 mM) and osmotic stress generated by polyethylene glycol (PEG) on PSII maximal quantum efficiency, photosynthetic CO2/H2O gas exchange at two CO2 concentrations, content of chlorophyll, proline, and malondialdehyde were investigated in shoots of C4 xerohalophyte Haloxylon aphyllum (Chenopodiaceae). The PEG treatment induced a low water osmotic potential (-0.4 MPa) and inhibited photosynthesis (by a factor of 2) and transpiration (by a factor of 4). The NaCl treatment, at equal osmoticity conditions, reduced transpiration (by a factor of 2) and stimulated photosynthesis (by a factor of 2.5). Only the PEG-treated plants showed osmotic stress effects, which were demonstrated by an increase in proline and malondialdehyde contents in the shoot tissue. The data indicated that the halophilic character of this species was essential for maintaining the plant water status and photosynthesis under osmoticity induced by NaCl treatment. Herewith, the presence of C4-type photosynthesis appeared to be just an auxiliary mechanism, because this xerohalophyte did not reveal the efficiency in water use typical for C4 plants under osmotic stress, in the absence of a saline substrate., Z. F. Rakhmankulova, P. Yu. Voronin, E. V. Shuyskaya, N .A. Kuznetsova, N. V. Zhukovskaya, K. N. Toderich., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
730. Effect of NaCl salinity on photosynthetic rate, transpiration rate, and oxidative stress tolerance in contrasting wheat genotypes
- Creator:
- Sharma, N., Gupta, N. K., Gupta, S., and Hasegawa, H.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- net photosynthetic rate, peroxidase, potassium, stomatal conductance, superoxide dismutase, transpiration rate, and Triticum
- Language:
- Multiple languages
- Description:
- Wheat (Triticum aestivum L.) genotypes K-65 (salt tolerant) and HD 2329 (salt sensitive) were grown in pots under natural conditions and irrigated with NaCl solutions of electrical conductivity (ECe) 4.0, 6.0, and 8.0 dS m-1. Control plants were irrigated without saline water. Observations were made on the top most fully expanded leaf at tillering, anthesis, and grain filling stages. The net photosynthetic rate (PN), stomatal conductance (gs), and transpiration rate (E) were reduced with the addition of NaCl. The reduction was higher in HD 2329 than in K-65. Salinity enhanced leaf to air temperature gradient (ΔT) in both the genotypes. NaCl increased the activities of superoxide dismutase (SOD) and peroxidase (POX); the percent increment was higher in K-65. The sodium and potassium contents were higher in the roots and leaves of K-65 over HD 2329. Thus at cellular level K-65 has imparted salt tolerance by manipulating PN, E, gs, and K accumulation in leaves along with overproduction of antioxidative enzyme activities (SOD and POX). and N. Sharma ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public