Number of results to display per page
Search Results
312. Photosynthesis and growth adaptation of Pterocarya stenoptera and Pinus elliottii seedlings to submergence and drought
- Creator:
- Yang, Y. and Li, C.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chinese wingnut, gas exchange, pine, soil redox potential, stomatal limitation, 2, and 581
- Language:
- Multiple languages
- Description:
- To uncover adaptation capacities of two flooding-tolerant plant species, Pterocarya stenoptera (a native species) and Pinus elliottii (an exotic species from southeastern USA), to alternating submergence and drought, we investigated their physiological and growth responses to water stress. Water treatments, including control, continuous flooding (CF), and periodic flooding and drought (PF), were applied to seedlings in order to simulate water level fluctuation in the hydrofluctuation zone of the Three Gorges Reservoir Region. Results showed that net photosynthetic rate (P N), stomatal conductance, and intrinsic water-use efficiency of both plant species were negatively affected under CF and PF compared with the corresponding controls. The P N of both species under PF was comparable to that under CF. At the end of the experiment, the ratio of intercellular to ambient CO2 concentration was not statistically different between water treatments, while that of P. elliottii was significantly higher than that of P. stenoptera. Although P. stenoptera formed lenticels under flooding conditions, P. elliottii seedlings allocated more mass to leaves and increased the relative growth rate of height to enhance the photosynthetic efficiency. Our results illustrated that P. stenoptera and P. elliottii seedlings developed different adaptive strategies in response to flooding, both CF and PF. Therefore, both P. stenoptera and P. elliottii are promising candidates for the vegetation reconstruction of the riparian zones in the Three Gorges Reservoir Region., Y. Yang, C. Li., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
313. Photosynthesis and growth of winter wheat in response to waterlogging at different growth stages
- Creator:
- Shao, G. C., Lan, J. J., Yu, S. E., Liu, N., Guo, R. Q., and She, D. L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, grain yield, wheat growth stages, milky stage, plant growth, tillering, Triticum aestivum, 2, and 581
- Language:
- Multiple languages
- Description:
- A study on photosynthetic and yield effects of waterlogging of winter wheat at four stages of growth was conducted in specially designed experimental tanks during the 2007-2008 and 2008-2009 seasons. Compared with the control, waterlogging treatments at tillering and jointing-booting stages reduced photosynthetic rate (PN) and transpiration (E) significantly, it also decreased average leaf water-use efficiency (WUE, defined as the ratio of PN to E) by 3.3% and 3.4% in both years. All parameters returned quickly to the control level after soil was drained. Damage to the photosynthetic apparatus during waterlogging resulted in a lower Fv/Fm ratio, especially at the first two stages. A strong reduction in root length, root mass, root/shoot ratio, total dry mass, and leaf area index were observed. The responses from vegetative plants at tillering and jointing-booting stages were greater than in generative plants at onset of flowering and at milky stages. The number of panicles per hectare at tillering stage and the spikelet per panicle at the stages of jointing-booting and at onset of flowering were also significantly reduced by waterlogging, giving 8.2-11.3% decrease of the grain yield relative to the control in both years. No significant difference in yield components and a grain yield was observed between the control and treatments applied at milky stages. These responses, modulated by the environmental conditions prevailing during and after waterlogging, included negative effects on the growth, photosynthetic apparatus, and the grain yield in winter wheat, but the effect was strongly stage-dependent. and G. C. Shao ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
314. Photosynthesis and leaf development of cherry tomato seedlings under different LED-based blue and red photon flux ratios
- Creator:
- Liu, X. Y., Jiao, X. L., Chang, T. T., Guo, S. R., and Xu, Z. G.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- chloroplasty, morfologie (biologie), chloroplasts, morphology (biology), leaf density, mesophyll cell, stomata, 2, and 581
- Language:
- Multiple languages
- Description:
- We investigated the photosynthesis and leaf development of cherry tomato seedlings grown under five different combinations of red and blue light provided by light-emitting diodes (LEDs). Fresh biomass increased significantly under treatments with blue light percentages of 50, 60, and 75%, with 50% blue-light-grown seedlings accumulating significantly more dry mass. The 25% blue-light-grown seedlings were obviously weaker than those from the other LED treatments. An increase in net photosynthetic rate upon blue light exposure (25-60%) was associated with increases in leaf mass per unit leaf area, leaf area, leaf density, stomatal number, chloroplast and mesophyll cell development, and chlorophyll contents. Our results imply that photosynthesis and leaf development in cherry tomato seedlings are associated with both the proportion and quantity of blue light., X. Y. Liu, X. L. Jiao, T. T. Chang, S. R. Guo, Z. G. Xu., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
315. Photosynthesis and photoprotection under drought in the annual desert plant Anastatica hierochuntica
- Creator:
- Eppel, A. and Rachmilevitch, S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, abiotic stress, relative water content, stomatal conductance, 2, and 581
- Language:
- Multiple languages
- Description:
- Anastatica hierochuntica is an annual desert plant, which was recently shown to have unusually low nonphotochemical quenching (NPQ) and a high PSII electron transport rate (ETR). In the current study, we examined how these unusual characteristics are related to a lack of CO2 and inhibition of net photosynthetic rate (P N). We compared the photosynthetic and photoprotective response of A. hierochuntica and sunflower (Helianthus annuus), under conditions of photosynthetic inhibition, with either low CO2 or drought. We found that under nonsteady state conditions of low CO2 availability, A. hierochuntica exhibited about half of the NPQ values and almost twice of the ETR values of H. annuus. However, the long-term inhibition of P N under drought caused a similar increase in NPQ and a decrease in ETR in both A. hierochuntica and H. annuus. These results suggest that the unusually low NPQ and high ETR in A. hierochuntica are not directly related to a response to drought conditions., A. Eppel, S. Rachmilevitch., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
316. Photosynthesis and physiology responses of paired near-isogenic lines in waxy maize (Zea mays L.) to nicosulfuron
- Creator:
- Wang, J., Zhong, X. M., Lv, X. L., Shi, Z. S., and Li, F. H.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, antioxidant enzymes, chlorophyll florescence, nicosulfuron, waxy maize, 2, and 581
- Language:
- Multiple languages
- Description:
- Nicosulfuron is a post-emergence herbicide used for weed control in fields of maize (Zea mays L.). We used a pair of nearly isogenic inbred lines, SN509-R (nicosulfuron-resistant) and SN509-S (nicosulfuron-sensitive), to study the effect of nicosulfuron on waxy maize seedling. After the nicosulfuron treatment, net photosynthetic rate, stomatal conductance, transpiration rate, leaf maximum photochemical efficiency of PSII, photochemical quenching of chlorophyll fluorescence, and the actual photochemical efficiency of PSII were significantly lower in SN509-S than those of SN509-R, contrary to intercellular CO2 concentration, stomatal limitation, and nonphotochemical quenching. Compared to SN509-R, antioxidant enzyme activities in SN509-S decreased significantly in response to the nicosulfuron treatment, while SN509-S exhibited an increased malondialdehyde content, which was associated with lower antioxidant enzyme activities. These results collectively suggest that the nicosulfuron-resistance mechanism was associated with photosynthetic rate, reactive oxygen species metabolism, and protective mechanisms., J. Wang, X. M. Zhong, X. L. Lv, Z. S. Shi, F. H. Li., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
317. Photosynthesis and salinity: are these mutually exclusive?
- Creator:
- Wungrampha, S., Joshi, R., Singla-Pareek, S. L., and Pareek, Ashwani
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- adaptace (biologie), chlorofyl, brakická rostlinná společenstva, fotosyntéza, adaptation (biology), chlorophyll, halophytes, photosynthesis, glycophytes, salinity, 2, and 581
- Language:
- Multiple languages
- Description:
- Photosynthesis has walked into the path of evolution for over millions of years. Organisms relying directly on photosynthesis, when subjected to adverse environments for a long duration, experience retardation in their growth and development. Salinity stress is perceived as one of the major threats to agriculture as it can cause an irreversible damage to the photosynthetic apparatus at any developmental stage of the plant. However, halophytes, a special category of plants, carry out all life processes, including photosynthesis, without showing any compromise even under high saline environments. The fascinating mechanism for Na+ exclusion from cytosol besides retaining photosynthetic efficiency in halophytes can provide a valuable genetic resource for improving salt stress tolerance in glycophytes. Understanding how plants stabilize their photosynthetic machinery and maintain the carbon balance under saline conditions can be extremely useful in designing crops for saline and dry lands., S. Wungrampha, R. Joshi, S. L. Singla-Pareek, A. Pareek., and Obsahuje bibliografické odkazy
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
318. Photosynthesis and ultrastructure of photosynthetic apparatus in tomato leaves under elevated temperature
- Creator:
- Zhang, J., Jiang, X. D., Li, T. L., and Cao, X. J.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, chloroplasty, rajčata, photosynthesis, chloroplasts, tomatoes, gas exchange, heat stress, Lycopersicon esculentum L, photosynthetic apparatus, microstructure, 2, and 581
- Language:
- Multiple languages
- Description:
- The microstructure of leaves and ultrastructure of chloroplasts were examined in tomato (Lycopersicon esculentum L.) plants treated with elevated temperature. Plants were exposed to 35°C for 30 d after florescence. The plants grown continuously under 25°C served as controls. Compared with the controls, the net photosynthetic rate (PN) in stressed plants decreased significantly. Stomatal conductance, intercellular CO2 concentrations, the rate of transpiration, and the limitation of stomatal conductance showed that the decrease in PN was caused mainly by nonstomatal restrictions. Meanwhile, stomata density increased significantly in the stressed plants. The stomata status of opening and closing became disorganized with a prolonged 35°C exposure. The damage of chloroplast membrane occurred earlier and was more serious in the plants under elevated temperature. At the same time, the thylakoids were loosely distributed with lesser grana, but the number of lipid droplets increased in chloroplasts. The number of starch grains in chloroplasts increased first and then decreased. In addition, the length of the main nerve in leaves increased and the main vein showed distortion in the plants stressed by 35°C. An increase was observed in the number of cells on the abaxial side of the main vein and these cells were overly congregated. The thickness of a vertical section became thinner in the stressed leaves. The cells of the upper epidermis thinned, and the ratio of palisade tissue to spongy tissue decreased. Generally, the photosynthetic apparatus of tomato changed significantly and the changed chloroplast ultrastructure might be one of the important reasons that caused the decrease of PN under 35°C., J. Zhang, X. D. Jiang, T. L. Li, X. J. Cao., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
319. Photosynthesis and yield traits in different soybean lines in response to salt stress
- Creator:
- He, Y., Chen, Y., Yu, C. L., Lu, K. X., Jiang, Q. S., Fu, J. L., Wang, G. M., and Jiang, D. A.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorofyl, chlorophyll, fluorescence chlorofylu, nefotochemické zhášení, fotochemické zhášení, stomatální vodivost, chlorophyll fluorescence, cyclic electron flow, electron transport rate, nonphotochemical quenching, photochemical quenching, stomatal conductance, 2, and 581
- Language:
- Multiple languages
- Description:
- To evaluate utility of different salt-tolerant lines, three soybean lines with different resistance to salt were planted in the field under control and salt-stress conditions for two years. The results showed that net photosynthetic rate (PN) was significantly different among lines at the anthesis stage and decreased on average by 13.6-34.1% under conditions of salt stress. The stomatal conductance was a primary limiting factor for the reduction of PN under salt stress. Meanwhile, the grain yield (GY) decreased on average by 14.0-35.3% among lines under salt stress. The salt-tolerant lines S111-9 and S113-6 showed higher PN and GY under salt stress in comparison with the salt-sensitive cultivar Melrose. Regression analysis indicated that there was extremely significantly positive correlation between GY and PN under field conditions. Therefore, PN might be used as a physiological index for field resistance of soybean to salt stress., Y. He, Y. Chen, C. L. Yu, K. X. Lu, Q. S. Jiang, J. L. Fu, G. M. Wang, D. A. Jiang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
320. Photosynthesis of a yellow-green mutant line in maize
- Creator:
- Zhong, X. M., Sun, S. F., Li, F. H., Wang, J., and Shi, Z. S.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, gene mutation, photochemical reaction, potential productivity, 2, and 581
- Language:
- Multiple languages
- Description:
- This study compared the relationship between chlorophyll (Chl) content, gas exchange, Chl fluorescence characteristics, and leaf color, using paired near-isogenic lines (NILs) of a medium-green leaf inbred line SN12 and a yellow-green leaf mutant SN62 to explore the photosynthesis of the yellow-green mutant. The SN62 was found in a female parent, Xianyu 335, which grew normally, although there were small yellow spots on the leaves at the seedling stage and yellow-green leaves appeared from the seedling to the maturation stage. The results indicated that Chl a (b), quantum efficiency of PSII, and maximal quantum yield of PSII photochemistry of SN62 were significantly lower than those of SN12, but there were almost no differences in the net photosynthetic rate (P N). There was no significant correlation between Chl a (b) and P N of inbred lines with different leaf colors. In the reproductive stage, photochemical quenching, effective quantum yield of PSII photochemistry, and the electron transport rate of SN62 increased obviously, and all parameter values exceeded the values of SN12. It explained that increasing the openness of the PSII reaction center was able to compensate for the lower Chl content, which was beneficial for harvesting more light energy for photochemical reactions. It also ensured that P N was not reduced., X. M. Zhong, S. F. Sun, F. H. Li, J. Wang, Z. S. Shi., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public