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32. Comparison of some photosynthetic characters between two hybrid rice combinations differing in yield potential
- Creator:
- Jiang, Hua, Wang, Xue-Hua, Deng, Qi-Yun, Yuan, Long-Ping, and Xu, Da-Quan
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carboxylation efficiency, chlorophyll, compensation CO2 concentration, compensation irradiance, dark respiration, net photosynthetic rate, Oryza sativa, photosystem 2, quantum yield, and stomatal conductance
- Language:
- Multiple languages
- Description:
- Photosynthetic characteristics of two hybrid rice combinations, Peiai 64S/E32 and Shanyou 63, were compared at the panicle differentiation stage. As compared with Shanyou 63, the new combination Peiai 64S/E32 showed a significantly higher net photosynthetic rate (PN), apparent quantum yield of carbon assimilation (Φc), carboxylation efficiency (CE), and photorespiratory rate (RP) as well as leaf chlorophyll content, but a significantly lower dark respiration rate (RD) and compensation irradiance (Ic). It also showed a slightly higher photochemical efficiency (Fv/Fm and ΔF/Fm') of photosystem 2, a lower non-photochemical quenching (qN), and a similar CO2 compensation concentration (Γ) as compared to Shanyou 63. and Hua Jiang ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
33. Comparison of the effects of salt-stress and alkali-stress on photosynthesis and energy storage of an alkali-resistant halophyte Chloris virgata
- Creator:
- Yang, C. W., Jianaer, A., Li, C. Y., Shi, D. C., and Wang, D. L.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- carotenoids, chlorophyll, leaf area, photosynthetic rate, relative growth rate, stomatal conductance, transpiration rate, and water content
- Language:
- Multiple languages
- Description:
- Seedlings of Chloris virgata were treated with varying (0-160 mM) salt-stress (SS; 1 : 1 molar ratio of NaCl to Na2SO4) or alkali-stress (AS; 1 : 1 molar ratio of NaHCO3 to Na2CO3). To compare these effects, relative growth rates (RGR), stored energy, photosynthetic pigment contents, net photosynthetic rates, stomatal conductance, and transpiration rates were determined. Both stresses did not change significantly the photosynthetic parameters of C. virgata under moderate stress (below 120 mM). Photosynthetic ability decreased significantly only at high stress (160 mM). Thus C. virgata, a natural alkali-resistant halophyte, adapts better to both kinds of stress. The inhibition effects of AS on RGR and energy storage of C. virgata were significantly greater than that of SS of the same intensity. The energy consumption of C. virgata was considerably greater while resisting AS than while resisting SS. and C. W. Yang ... [et al.]
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
34. Compensatory acclimated mechanisms of photoprotection in a Xa mutant of Lycopersicon esculentum Mill.
- Creator:
- Wang, Y. J., Xia, X. J. , Zhou, Y. H., and Yu, J. Q.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- chlorophyll fluorescence, CO2, concentration, net photosynthetic rate, non-photochemical quenching, photoprotection, photosynthetic electron flux, quenching, reactive oxygen species, stomatal conductance, tomato, and xanthophyll cycle
- Language:
- Multiple languages
- Description:
- To probe the role of xanthophylls in non-photochemical quenching (NPQ) and the compensatory acclimated photoprotection mechanisms, a tomato (Lycopersicon esculentum Mill. cv. Ailsa Craig) Xa mutant with deficit in lutein (L) and neoxanthin (N) contents was used. The Xa mutant showed lowered NPQ, an increased degree of de-epoxidation state [(A+Z)/(V+A+Z)], and decreases of photosystem 2 (PS2) antenna size. Although the Xa mutant had a CO2 assimilation rate similar to that of Ailsa Craig, it exhibited a much larger stomatal conductance (gs) than Ailsa Craig. Decreased electron flux in PS2 (J PS2) for the Xa mutant was associated with electron flux for photorespiratory carbon oxidation (Jo) and alternative electron flux in PS2 (Ja) while electron flux for photosynthetic carbon reduction (Jc) was not different from Ailsa Craig. Moreover, the Xa mutant also exhibited higher activities of antioxidant enzymes, higher contents of ascorbate and glutathione, and lower contents of reactive oxygen species. Hence some compensatory acclimated mechanisms of photoprotection operated properly in the lack of NPQ and xanthophylls. and Y. J. Wang ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
35. Compensatory effects of elevated CO2 concentration on the inhibitory effects of high temperature and irradiance on photosynthetic gas exchange in carrots
- Creator:
- Thiagarajan, A., Lada, R., and Joy, P.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- Daucus, stomatal conductance, transpiration rate, and water use efficiency
- Language:
- Multiple languages
- Description:
- We determined the interactive effects of irradiance, elevated CO2 concentration (EC), and temperature in carrot (Daucus carota var. sativus). Plants of the cv. Red Core Chantenay (RCC) were grown in a controlled environmental plant growth room and exposed to 3 levels of photosynthetically active radiation (PAR) (400, 800, 1 200 µmol m-2 s-1), 3 leaf chamber temperatures (15, 20, 30 °C), and 2 external CO2 concentrations (Ca), AC and EC (350 and 750 µmol mol-1, respectively). Rates of net photosynthesis (PN) and transpiration (E) and stomatal conductance (gs) were measured, along with water use efficiency (WUE) and ratio of internal and external CO2 concentrations (Ci/Ca). PN revealed an interactive effect between PAR and Ca. As PAR increased so did PN under both C a regimes. The gs showed no interactive effects between the three parameters but had singular effects of temperature and PAR. E was strongly influenced by the combination of PAR and temperature. WUE was interactively affected by all three parameters. Maximum WUE occurred at 15 °C and 1 200 µmol m-2 s-1 PAR under EC. The Ci /Ca was influenced independently by temperature and Ca. Hence photosynthetic responses are interactively affected by changes in irradiance, external CO2 concentration, and temperature. EC significantly compensates the inhibitory effects of high temperature and irradiance on PN and WUE. and A. Thiagarajan, R. Lada, P. Joy.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
36. Contribution of leaf nitrogen to photosynthetic gas exchange in contrasting rice (Oryza sativa L.) cultivars during the grain-filling period
- Creator:
- Shimoda, S.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- botanika, botany, carbon discrimination, nitrogen supply, photosynthetic CO2 assimilation, stomatal conductance, 2, and 58
- Language:
- Multiple languages
- Description:
- Photosynthetic parameters and leaf carbon isotope composition (δ13C) in contrasting rice genotypes in relation to supplemental nitrogen (N) application and water management during the grain-filling period were compared. The changes in stomatal conductance (gs) and ratio of intercellular to ambient CO2 mole fraction (Ci/Ca) depended on the leaf nitrogen concentration (leaf N) in both ‘Hinohikari’ (temperate japonica genotype) and ‘IR36’ (indica genotype). In ‘Hinohikari’, δ13C reflects photosynthetic gas exchange during the grain-filling period, which is indicated by the significant response of δ13C to leaf N. In contrast, in ‘IR36’ δ13C did not depend on leaf N. This varietal difference in δ13C to leaf N can be attributed to a difference in the timing of leaf senescence. In ‘IR36’, leaf N and photosynthetic parameters decreased more rapidly, indicating earlier senescence and a shorter grain-filling period in comparison with ‘Hinohikari’. The significant increase in shoot dry mass in ‘Hinohikari’ resulting from supplemental N application, compared with nonsignificant effect observed in ‘IR36’, suggests that the timing of senescence in relation to the grainfilling period has a preponderant influence on productivity., S. Shimoda., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
37. Contribution of pre-anthesis assimilates and current photosynthesis to grain yield, and their relationships to drought resistance in wheat cultivars grown under different soil moisture
- Creator:
- Inoue, T., Inanaga, S., Sugimoto, Y., and El Siddig, K.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- cultivar differences, intercellular CO2 concentration, net photosynthetic rate, remobilization, stomatal conductance, Triticum aestivum, and water stress
- Language:
- Multiple languages
- Description:
- We investigated the relative importance of pre-anthesis assimilates stored in plant parts, mainly in the stem, and post-anthesis photosynthesis to drought resistance in wheat (Triticum aestivum L.) cultivars Hongwangmai (drought resistant) and Haruhikari (drought sensitive) subjected to two soil moisture regimes: irrigated and non-irrigated. In the irrigated treatment, soil moisture was maintained near field capacity throughout the growing season, while in the non-irrigated treatment water was withheld from 81 d after sowing until maturity. Drought stress reduced grain yield of Hongwangmai and Haruhikari by 41 and 60 %, respectively. Remobilization of pre-anthesis assimilates to the grain (remobilization) was reduced by drought in Hongwangmai but increased in Haruhikari. The contribution of pre-anthesis assimilates to the grain decreased under non-irrigated treatment in Hongwangmai. However, under water stress, Hongwangmai maintained a higher net photosynthetic rate in the flag leaf than Haruhikari. These results indicated that maintenance of post-anthesis photosynthetic rate was related to drought resistance in Hongwangmai rather than to remobilization under drought stress. and T. Inoue ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
38. Crassulacean acid metabolism in the epiphytic fern Patycerium bifurcatum
- Creator:
- Rut, G., Krupa, J., Miszalski, Z., Rzepka, A., and Ślesak, I.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- abscisic acid, chlorophyll fluorescence, drought stress, malate, net photosynthetic rate, photosystem 2, and stomatal conductance
- Language:
- Multiple languages
- Description:
- The epiphytic fern Platycerium bifurcatum grows in different habitats characterized by drought and high irradiance stress. The plant shows diurnal malate oscillations, indicative for CAM expression only in cover leaves, but not in sporotrophophyll. In P. bifurcatum cover leaves exposed to high irradiance and desiccation, the decrease in both CO2 assimilation (PN) and stomatal conductance (gs) was accompanied with occurrence of diurnal malate oscillations. Exogenously applied abscisic acid (ABA) induced the decrease in PN and gs, but no clear change in malate oscillations. The measurements of the maximum quantum efficiency of photosystem 2 (Fv/Fm) under high irradiance showed distinct photoinhibition, but no clear changes in Fv/Fm due to desiccation and ABA-treatment were found. and G. Rut ... [et al.].
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
39. Daily irradiance and feedback inhibition of photosynthesis at elevated carbon dioxide concentration in Brassica oleracea
- Creator:
- Bunce, J. A. and Sicher, R. C.
- Format:
- bez média and svazek
- Type:
- model:article and TEXT
- Subject:
- collard, irradiance, kohlrabi, saccharides, stomatal conductance, and variety differences
- Language:
- Multiple languages
- Description:
- The fundamental cause of down-regulation of photosynthesis at elevated carbon dioxide concentration (EC) is thought to be a slower rate of utilization of saccharides than their stimulated rate of production, but there are few studies directly supporting this idea under field conditions. We hypothesized that within Brassica oleracea, down-regulation would not occur in kohlrabi because it has a large sink for saccharides in an enlarged stem, but would occur in collards, which lack this sink. Field tests were consistent with this hypothesis. In collards, the degree of down-regulation of photosynthesis in plants grown at EC varied depending on the daily integral of photosynthetically active radiation (PAR) of the day prior to the measurement of photosynthetic capacity, as did leaf saccharide content. However, EC did not result in lower leaf contents of chlorophyll, soluble protein, ribulose-1,5-bisphosphate carboxylase, or nitrate in collards, nor was there any evidence of a triose phosphate utilization rate limiting photosynthesis. Experiments in controlled environment chambers confirmed that there was a threshold response for the down-regulation of photosynthesis in collards at EC to the PAR of the previous day, with down-regulation only occurring above a minimum daily integral of PAR. Down-regulation of photosynthesis could be induced in plants grown at ambient carbon dioxide by a single night at low temperature or by a single day with high PAR and EC. In the controlled environment study, the degree of down-regulation of photosynthesis was highly correlated with leaf glucose, fructose, and sucrose contents, and less well correlated with starch content. Hence down-regulation of photosynthesis at EC in collards in the field represented feedback inhibition from the accumulation of soluble saccharides and day-to-day variation in its occurrence was predictable from the weather. and J. A. Bunce, R. C. Sicher.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
40. Daily temperature drop prevents inhibition of photosynthesis in tomato plants under continuous light
- Creator:
- Ikkonen, E. N., Shibaeva, T. G., Rosenqvist, E., and Ottosen, C.-O.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, photosynthesis, chlorophyll fluorescence, gas exchange, leaf area, photodamage, stomatal conductance, 2, and 581
- Language:
- Multiple languages
- Description:
- The negative effects of continuous light (CL) seen in tomato plants are often claimed to be linked to effects of offsetting the diurnal rhythm. In this study we tested whether a short-term daily temperature drop prevents the decreased photosynthetic performance seen in tomato plants grown under CL. Tomato (Lycopersicon esculentum Mill.) plantlets were grown at constant temperature of 26°C under 16-h day (16D) or 24-h day (24D) at 150 μmol m-2 s-1 PPFD. Some 24D plants were treated daily by 2 h temperature drop from 26 to 10°C (24D+DROP). Physiological disorder, such as severe leaf chlorosis, a large decrease in net photosynthetic rate, maximal quantum yield of PSII photochemistry, and the effective quantum yield of PSII photochemistry were observed in 24D, but not in 16D and 24D+DROP plants. The daily 2-h drop in temperature eliminated a negative effect of CL on photosynthesis and prevented the development of leaf chlorosis in tomato plants. This could be due to a change in carbohydrate metabolism as the short drop in temperature might allow maintenance of the diurnal rhythms., E. N. Ikkonen, T. G. Shibaeva, E. Rosenqvist, C.-O. Ottosen., and Obsahuje seznam literatury
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public