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Start Over Language Multiple languages Subject chlorophyll Subject net photosynthetic rate

21. Low iron stress nutrition for evaluation of Fe-efficient genotype physiology, photosynthesis, and essential monoterpene oil(s) yield of Ocimum sanctum

Creator:
Misra, A., Dwivedi, S., Srivastava, A. K., Tewari, D. K., Khan, A., and Kumar, R.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll, Cu, dry mass, Fe, leaf area, Mn, net photosynthetic rate, plant height, saccharides, and Zn
Language:
Multiple languages
Description:
Genotypic variations were observed among 6 variants and an indigenous one as a control. An efficient genotype OCD(L) of Ocimum sanctum had the greatest content of chlorophylls [2.15 g kg-1(FM)], Chl a/b ratio of 1.86, net photosynthetic rate of 0.72 mg(CO2) m-2 s-1, and 1.56 % oil formation. Methyl chavicol formed 50.31 % of total oil in OSP-6 genotype, which had also maximum peroxidase activity [ΔOD 2.4 mg-1(protein)] and maximum production of eugenol (30.44 % of total oil). We found an oxido-reducible reaction of peroxidase and high bands of peroxidase isoenzymes in this OSP-6 genotype for the formation of monoterpene essential oil(s) and possibly the major constituents of eugenol through the high production of photosynthates. and A. Misra ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

22. Low night temperature-induced changes in photosynthesis and rubber accumulation in guayule (Parthenium argentatum Gray)

Creator:
Sundar, D. and Ramachandra Reddy, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll, fructose-6-phosphate, net photosynthetic rate, photosystems 1 and 2, proteins, rubber transferase, starch, saccharose, sucrose phosphate synthase, and superoxide dismutase
Language:
Multiple languages
Description:
Three-year-old plants of Parthenium argentatum Gray cv. 11591 grown under natural photoperiod were exposed for 60 d to low night temperature (LNT) of 15 °C (daily from 18:00 to 06:00). Effects of the treatment on net photosynthetic rates (PN), rubber accumulation, and associated biochemical traits were examined. LNT initially reduced PN with a parallel decline in the activities of ribulose-1,5-bisphosphate carboxylase, fructose bisphosphatase, and sucrose phosphate synthase for 20-30 d. Later, LNT enhanced PN and the activities of photosynthetic enzymes. Associated with high PN in LNT-treated guayule plants was a two-fold increase in rubber content and rubber transferase activity per unit of protein. The initial decrease in PN in LNT-treated guayule was associated with low content of chlorophyll (a+b), large starch accumulation, and higher ratio of glucose-6-phosphate/fructose-6-phosphate. Photosystem 2 activity in isolated chloroplasts was initially decreased, but increased after 30 d. There was a significant increase in the leaf soluble protein content in LNT-treated plants. Hence the photosynthetic performance of plants grown at 15 °C night temperature for 50 d was superior to those grown under natural photoperiod in all parameters studied. The high photosynthetic capacity may contribute to superior rubber yields under LNT. and D. Sundar, A. Ramachandra Reddy.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

23. Modelling net photosynthetic rate of winter wheat in elevated air CO2 concentrations

Creator:
Harnos, N., Tuba, Z., and Szente, K.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
acclimation, carotenoids, chlorophyll, intercellular CO2 concentration, leaf area, net photosynthetic rate, ribulose-1,5-bisphosphate carboxylase/oxygenase capacity, temperature, and Triticum aestivum
Language:
Multiple languages
Description:
Winter wheat plants were grown in open top chambers either at 365 µmol mol-1 (AC) or at 700 µmol mol-1 (EC) air CO2 concentrations. The photosynthetic response of flag leaves at the beginning of flowering and on four vertical leaf levels at the beginning of grain filling were measured. Net photosynthetic rates (PN) were higher at both developmental phases in plants grown at EC coupled with larger leaf area and photosynthetic pigment contents. The widely accepted Farquhar net photosynthesis model was parameterised and tested using several observed data. After parameterisation the test results corresponded satisfactorily with observed values under several environmental conditions. and N. Harnos, Z. Tuba, K. Szente.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

24. Monitoring leaf photosynthesis with canopy spectral reflectance in rice

Creator:
Tian, Y., Zhu, Y., and Cao, W.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll, leaf area index, net photosynthetic rate, nitrogen supply, Oryza sativa, remote sensing, and water content
Language:
Multiple languages
Description:
Non-destructive and rapid method for assessment of leaf photosynthetic characteristics is needed to support photosynthesis modelling and growth monitoring in crop plants. We determined the quantitative relationships between leaf photosynthetic characteristics and canopy spectral reflectance under different water supply and nitrogen application rates. The responses of reflectance at red radiation (wavelength 680 nm) to different water contents and nitrogen rates were parallel to those of leaf net photosynthetic rate (PN). The relationships of reflectance at 680 nm and ratio index of R(810,680) (near infrared/red, NIR/R) to PN of different leaf positions and leaf layers in rice indicated that the top two full leaves were the best leaf positions for quantitative monitoring of leaf PN with remote sensing technique, and the ratio index R(810,680) was the best ratio index for evaluating leaf photosynthetic characteristics in rice. Testing of the models with independent data sets indicated that R(810,680) could well estimate PN of top two leaves and canopy leaf photosynthetic potential in rice, with the root mean square error of 0.25, 0.16, and 4.38, respectively. Hence R(810,680) can be used to monitor leaf photosynthetic characteristics at different growth stages of rice under diverse growing conditions. and Y. Tian, Y. Zhu, W. Cao.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

25. Photosynthesis and associated metabolism during development of a Theobroma cacao hybrid with the lethal factor Luteus-Pa

Creator:
de Almeida, A.-A. F., Valle, R. R., and Serrano Minar, P.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
amino acids, cacao, chlorophyll, fluorescence induction, net photosynthetic rate, pigment-protein complexes, plant phylogeny, saccharides, and transpiration
Language:
Multiple languages
Description:
The recessive lethal character Luteus-Pa, expressed as a yellowing of leaves of young seedlings and followed by death approximately 60 d after emergence, presents a 3:1 segregation in crosses and/or selfpollinated plants. We evaluated quantitatively the fluorescence emission of chlorophyll (Chl), gas exchange, and chemical composition of normal and recessive homozygous cacao seedlings of the cross Pa 121×Pa 169. The characteristics of Chl fluorescence kinetics were studied in stages B2, B3, C, D, and E of leaf development, corresponding to plant ages of 9 to 12, 13 to 15, 16 to 20, 21 to 30, and >30 d, respectively. Gas exchanges were measured in mature leaves of both seedlings. In regular intervals of 3 d beginning at 33 d after emergence, the seedlings were separated into roots, stems, leaves, and cotyledons to determine the contents of saccharides (SAC) and free amino acids (FAA) and variation of the leaf Chl content. The Chl distribution in complexes of the photosynthetic apparatus was analysed by SDS-PAGE in mature leaves of both normal and recessive 32-d-old seedlings. There were variations in Chl fluorescence, gas exchanges and chemical composition of different parts of both types of seedlings. However, no significant differences were found in the Chl distribution through photosynthetic complexes of 32-d-old normal and recessive homozygous seedlings. After that period a decrease in the Chl concentration was observed in the recessive seedlings, and only minimum fluorescence (F0) was found. The F0 values were higher in the recessive seedlings than in the normal ones. The net photosynthetic rate of mature leaves was negative in agreement with low conductance, transpiration rate, and high internal CO2 concentration. These factors might have contributed to a depletion in SAC in different plant parts. Although F0 partially reflects the Chl concentration in leaf tissue, the increase in its value was probably due to a damage in reaction centres of photosystem 2. Therefore, the growth and development of recessive homozygous seedlings depended exclusively on cotyledon reserves, the depletion of which leads to death. and A.-A. F. de Almeida, R. R. Valle, P. Serrano Minar.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

26. Photosynthesis in Platycerium coronarium (Koenig ex Mueller) Desv.

Creator:
Ong, Bee-Lian, NG, Sock-Ling, and Wee, Yeow-Chin
Format:
print
Type:
model:internalpart and TEXT
Subject:
chlorophyll, specific leaf mass, senescence, respiration rate, quantum yield, net photosynthetic rate, nest and pendulous fronds, dry and fresh mass, and compensation and saturation irradiance
Language:
Multiple languages
Description:
In the dimorphic stag’s hom fem, Platycerium coronarium (Koenig ex Mueller) Desv., photosynthetic characters and chlorophyll (Chl) contents were deteiinined in both nést and pendulous fronds at different stages of ontogeny and at different positions along the longest length of each frond. Area-specific radiant energy- saturated net photosynthetic (P^) and dark respiration rates, dry mass-specific Chl content and quantum yield increased during frond development and decreased when senescence set in. Radiant energy-saturated and dry-mass specific Chl content were greatest in the youngest tissues of each frond. In addition to the functions ascribed to the nést (water and nutrient collection) and pendulous (reproduction) fronds, the results indicate the important roles of both frond types in providing Chemical energy to the growth and survival of the plant.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

27. Photosynthesis of cockspur [Echinochloa crus-galli (L.) Beauv.] at sites of naturally elevated CO2 concentration

Creator:
Vodnik, D., Pfanz, H., Maček, I., Kastelec, D., Lojen, S., and Batič, F.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
carbon dioxide springs, chlorophyll, CO2 compensation concentration, intercellular CO2 concentration, net photosynthetic rate, plant height, stomatal conductance, and δ13C
Language:
Multiple languages
Description:
High abundance of cockspur (Echinochloa crus-galli) at the geothermal carbon dioxide spring area in Stavešinci indicates that this species is able to grow under widely varying CO2 concentrations. Living cockspur plants can even be found very close to gas-releasing vents where growth is significantly reduced. Plant height correlated well with CO2 exposure. The δ13C value of the CO2 spring air was -3.9 ‰ and δ13C values of high-, medium-, and low-CO2 plants were -10.14, -10.44, and -11.95 ‰, respectively. Stomatal response directly followed the prevailing CO2 concentrations, with the highest reduction of stomatal conductance in high CO2 concentration grown plants. Analysis of the curves relating net photosynthetic rate to intercellular CO2 concentration (PN-Ci curves) revealed higher CO2 compensation concentration in plants growing at higher CO2 concentration. This indicates adjustment of respiration and photosynthetic carbon assimilation according to the prevailing CO2 concentrations during germination and growth. There was no difference in other photosynthetic parameters measured. and D. Vodnik ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

28. Photosynthesis of Hedera canariensis var. azorica variegated leaves as affected by ozone

Creator:
Soldatini, G. F., Nali, C., Guidi, L., and Lorenzini, G.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll, fluorescence, ivy, net photosynthetic rate, stomatal conductance, and transpiration
Language:
Multiple languages
Description:
A differential response to long-term ozone exposures (50 and 100 mm3 m-3) was observed in the green and white areas of variegated leaves of Hedera canariensis var. azorica L. In green tissue the photosynthetic activity was depressed via a stomatal mechanism, and in white regions no effect was observed. Chlorophyll fluorescence parameters remained unchanged in green portions, whereas in the white ones Fm and Fv/Fm significantly diminished following ozone fumigation. and G. F. Soldatini ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

29. Photosynthetic characteristics of Ipomoea pescaprae Forsk. under NaCl stress

Creator:
Venkatesan, A., Venkatesalu, V., and Chellappan, K.P.
Format:
print
Type:
model:internalpart and TEXT
Subject:
chlorophyll, ill reaction activity, net photosynthetic rate, photosystem 2, and salinity
Language:
Multiple languages
Description:
Sodium chloride salinity had enhanced the photosynthetic rate, photosystem 2 activity and chlorophyll synthesis in isolated leaf cells of Ipomoea pescaprae up to 200 mM NaCl. The salt treated plants did not show any shift in the mode of photosynthesis.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

30. Photosynthetic characteristics, dark respiration, and leaf mass per unit area in seedlings of four tropical tree species grown under three irradiances

Creator:
Feng, Y.-L., Cao, K.-F., and Zhang, J.-L.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
acclimation to irradiance, Anthocephalus, Barringtonia, Calophyllum, carboxylation efficiency, chlorophyll, leaf mass per unit area, Linociera, net photosynthetic rate, and nitrogen
Language:
Multiple languages
Description:
We investigated the effect of growth irradiance (I) on photon-saturated photosynthetic rate (Pmax), dark respiration rate (RD), carboxylation efficiency (CE), and leaf mass per unit area (LMA) in seedlings of the following four tropical tree species with contrasting shade-tolerance. Anthocephalus chinensis (Rubiaceae) and Linociera insignis (Oleaceae) are light-demanding, Barringtonia macrostachya (Lecythidaceae) and Calophyllum polyanthum (Clusiaceae) are shade-tolerant. Their seedlings were pot-planted under shading nets with 8, 25, and 50 % daylight for five months. With increase of I, all species displayed the trends of increases of LMA, photosynthetic saturation irradiance, and chlorophyll-based Pmax, and decreases of chlorophyll (Chl) content on both area and mass bases, and mass-based Pmax, RD, and CE. The area-based Pmax and CE increased with I for the light-demanders only. Three of the four species significantly increased Chl-based CE with I. This indicated the increase of nitrogen (N) allocation to carboxylation enzyme relative to Chl with I. Compared to the two shade-tolerants, under the same I, the two light-demanders had greater area- and Chl-based Pmax, photosynthetic saturation irradiance, lower Chl content per unit area, and greater plasticity in LMA and area- or Chl-based Pmax. Our results support the hypothesis that light-demanding species is more plastic in leaf morphology and physiology than shade-tolerant species, and acclimation to I of tropical seedlings is more associated with leaf morphological adjustment relative to physiology. Leaf nitrogen partitioning between photosynthetic enzymes and Chl also play a role in the acclimation to I. and Y.-L. Feng, K.-F. Cao, J.-L. Zhang.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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