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11. Gas exchange characteristics and water relations in some elite okra cultivars under water deficit

Creator:
Ashraf, M., Arfan, M., Shahbaz, M., Ahmad, Ashfaq, and Jamil, A.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
chlorophyll, drought stress, Hibiscus esculentus, osmotic adjustment, photosynthetic rate, stomatal conductance, transpiration rate, and water relations
Language:
Multiple languages
Description:
M. Ashraf ... [et al.].
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

12. Gas-exchange response of almond genotypes to water stress

Creator:
Karimi, S., Yadollahi, A., Arzani, K., Imani, A., and Aghaalikhani, M.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, mandloně, photosynthesis, almonds, Írán, Iran, leaf temperature, leaf water potential, photosynthetic rate, Prunus dulcis Mill., water stress, relative water content, stomatal conductance, 2, and 581
Language:
Multiple languages
Description:
We studied water relations and gas exchange in six almond genotypes grafted on GF677 in response to withholding irrigation for 14 days and a subsequent 10-day rehydration period. The responses to drought stress significantly differed in the almond genotypes; the tolerant plants were distinguished and monitored. Leaf relative water content (RWC) decreased by more than 23%, leaf water potential dropped to less than -4.3 MPa, and electrolyte leakage increased to 43% in dehydration-sensitive genotypes. Photosynthesis (PN) and stomatal conductance (gs) of drought-sensitive genotypes were significantly reduced by 70% and 97% in response to water deficiency. Water stress significantly enhanced wateruse efficiency up to 10 folds in drought-tolerant almonds. The difference between leaf temperature and its surrounding air temperature (ΔT) increased significantly to more than 187% under water stress in drought-tolerant genotypes. In addition, the reduction in the g s and further ability to preserve RWC were involved probably in drought-tolerance mechanism in almond. Negative significant correlations were found between ΔT, PN, and gs. Based on the correlations, we suggested that ΔT could be used as a simple measurement for monitoring water stress development in the irrigation management of almond orchards. In conclusion, ‘Supernova’ and the Iranian genotypes ‘6-8’ and ‘B-124’, were found to be more droughttolerant compared with other genotypes in this experiment., S. Karimi, A. Yadollahi, K. Arzani, A. Imani, M. Aghaalikhani., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

13. Genetic basis of traits related to stomatal conductance in wheat cultivars in response to drought stress

Creator:
Wang, S. G., Jia, S. S., Sun, D. Z., Wang, H. Y., Dong, F. F., Ma, H. X., Jing, R. L., and Ma, G.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, pšenice, photosynthesis, wheat, drought stress, photosynthetic rate, quantitative trait loci, stomatal conductance, transpiration rate, 2, and 581
Language:
Multiple languages
Description:
The genetic basis of stomatal conductance (gs), net photosynthetic rate (PN), and transpiration rate (E) was explored by using a wheat doubled haploid population from a cross of Hanxuan10 and Lumai 14. The above three traits were evaluated in wheat flag leaves at 10, 20, 30 days after anthesis under drought stress (DS) and well-watered (WW), and quantitative trait loci (QTL) were analyzed. Expression of the traits during the grain filling stage showed downward trends under both conditions, but expression of three phenotypes were stronger under WW than those under DS. Extremely significant positive correlations were established among the traits at all growth stages under both conditions. A total of 18 additive QTLs for those traits were identified on 10 chromosomes. Among them, two batches of nine additive QTLs were associated with the target traits under DS and WW, respectively. Two additive QTLs for gs and E, two for gs and PN, six for gs, PN, and E clustered at the same or near the region (colocation) of chromosomes 4A, 2B, and 7B, respectively. This provided genetic basis for close phenotype correlations among gs, PN, and E. Furthermore, QTLs for gs, PN, and E near Xgwm577 and Xgwm611 located on 7B chromosome were linked to previously reported QTLs regulating a SPAD value and the chlorophyll a/b ratio under dark-induced condition. This finding indicated that these QTLs on 7B chromosome might be involved in the process of wheat leaf senescence., S. G. Wang, S. S. Jia, D. Z. Sun, H. Y. Wang, F. F. Dong, H. X. Ma, R. L. Jing, G. Ma., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

14. Growth and photosynthetic characteristics of Nigella sativa L. as affected by presowing seed treatment with kinetin

Creator:
Shah, S. H.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, carbonic anhydrase, chlorophyll, kinetin, Nigella sativa, nitrate reductase, photosynthetic rate, protein, seed treatment, and stomatal conductance
Language:
Multiple languages
Description:
Black cumin (Nigella sativa L.) seeds were surface-sterilized and soaked for 5, 10, or 15 h in 1, 10, or 100 μM aqueous solution of kinetin (KIN). The potted plants were then analyzed at 30, 50, and 70 days after emergence (DAE) for dry mass (DM), leaf area (LA), chlorophyll (Chl) content, stomatal conductance (g s), carbonic anhydrase (CA), and nitrate reductase (NR) activity, total protein content, and net photosynthetic rate (PN). Capsule number and seed yield were determined at harvest (90 DAE). Treatment with the growth regulator was found to appreciably enhance all the determinants, with most prominent results being obtained following 10-h soaking with 10 μM KIN, in which case the values for DM, LA, PN, CA and NR activity, and seed yield were elevated by 55, 63, 43, 38, 29, and 23% respectively over the control at the 50-day stage. and S. H. Shah.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

15. Light induction of nonphotochemical quenching, CO2 fixation, and photoinhibition in woody and fern species adapted to different light regimes

Creator:
Wong, S.-L., Huang, M.-Y., Chen, C.-W., and Weng, J.-H.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
fotosyntéza, photosynthesis, light adaptation, NPQ, photoinhibition, photosynthetic induction, photosynthetic rate, 2, and 581
Language:
Multiple languages
Description:
We aimed to find out relations among nonphotochemical quenching (NPQ), gross photosynthetic rate (PG), and photoinhibition during photosynthetic light induction in three woody species (one pioneer tree and two understory shrubs) and four ferns adapted to different light regimes. Pot-grown plants received 100% and/or 10% sunlight according to their light-adaptation capabilities. After at least four months of light acclimation, CO2 exchange and chlorophyll fluorescence were measured simultaneously in the laboratory. We found that during light induction the formation and relaxation of the transient NPQ was closely related to light intensity, light-adaption capability of species, and PG. NPQ with all treatments increased rapidly within the first 1-2 min of the light induction. Thereafter, only species with high PG and electron transport rate (ETR), i.e., one pioneer tree and one mild shade-adapted fern, showed NPQ relaxing rapidly to a low steady-state level within 6-8 min under PPFD of 100 μmol(photon) m-2 s-1 and ambient CO2 concentration. Leaves with low PG and ETR, regardless of species characteristics or inhibition by low CO2 concentration, showed slow or none NPQ relaxation up to 20 min after the start of low light induction. In contrast, NPQ increased slowly to a steady state (one pioneer tree) or it did not reach the steady state (the others) from 2 to 30 min under PPFD of 2,000 μmol m-2 s-1. Under high excess of light energy, species adapted to or plants acclimated to high light exhibited high NPQ at the initial 1 or 2 min, and showed low photoinhibition after 30 min of light induction. The value of fastest-developing NPQ can be quickly and easily obtained and might be useful for physiological studies., S.-L. Wong, M.-Y. Huang, C.-W. Chen, J.-H. Weng., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

16. Limitations of photosynthesis in Phaseolus vulgaris under drought stress: gas exchange, chlorophyll fluorescence and Calvin cycle enzymes

Creator:
Dias, M. C. and Brüggemann, W.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, Calvin cycle enzymes, chlorophyll fluorescence, drought stress, Phaseolus vulgaris, and photosynthetic rate
Language:
Multiple languages
Description:
In this article, the effects of drought stress (DS) on gas exchange, chlorophyll (Chl) a fluorescence and Calvin cycle enzymes in Phaseolus vulgaris are evaluated. Three-week-old plants were exposed to DS by receiving only so much water every evening to ensure 30% field capacity water content overnight. After three days under these conditions, we observed that DS induced a decline of the CO2 assimilation. Gas-exchange data showed that the closure of stomata during DS did not lead to a concomitant decline in calculated intercellular CO2 concentration. Moreover, DS plants showed a reduction of the photochemical Chl fluorescence quenching, photosystem II quantum yield and electron transport rate and a higher pH gradient and more heat dissipation as compared to controls. The activity of Calvin cycle enzymes, Rubisco, sFBPase, and Ru5PK, decreased strongly in DS plants as compared to controls. Data analysis suggest that the decrease of CO2 assimilation under drought conditions is not related to a diminished capacity of the use of NADPH and ATP but probably to the decline of enzyme activity involved in RuBP regeneration (Ru5PK). and M. C. Dias, W. Brüggemann.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

17. Lotus corniculatus L. response to carbon dioxide concentration and radiation level variations

Creator:
Kostopoulou, P. and Karatassiou, M.
Format:
print, bez média, and svazek
Type:
model:article and TEXT
Subject:
světlo, light, elevace, index plasticity, ambient conditions, birdsfoot trefoil, elevation, photosynthetic rate, plasticity index, 2, and 581
Language:
Multiple languages
Description:
Carbon dioxide concentration and light conditions may greatly vary between mountainous and lowland areas determining the photosynthetic performance of plants species. This paper aimed to evaluate the photosynthetic responses of Lotus corniculatus, growing in a mountain and a lowland grassland, under low and high radiation and CO2 concentration. Net photosynthetic rate, stomatal conductance, transpiration rate, and intercellular CO2 concentration were measured while the water-use efficiency and the ratio of variable to maximal fluorescence were calculated. Photosynthetic response curves to different levels of radiation and intercellular CO2 partial pressure were estimated. Our results showed that high radiation and CO2 concentration enhanced water-use efficiency of plants at both sites, enabling them to use more efficiently the available water reserves under drought conditions. The increase of radiation and CO2 concentration would enhance the photosynthetic performance of the mountainous population of L. corniculatus, which overall seems to express higher phenotypic plasticity., P. Kostopoulou, M. Karatassiou., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

18. Photorespiration rate in spinach leaves under moderate NaCl stress

Creator:
di Martino, C., Delfine, S., Alvino, A., and Loreto, F.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
amino acids, carboxylation rate, electron transport rate, oxygenation rate, photosynthetic rate, and Spinacia oleracea
Language:
Multiple languages
Description:
We analyzed the effect of NaCl stress on photorespiration of spinach leaves by calculating the rate of carboxylation/oxygenation of ribulose-1,5-bisphosphate carboxylase/oxygenase, and by measuring the content of amino acids produced through photorespiration. After 20 d of NaCl stress the carboxylation rate was reduced while the oxygenation rate was not affected. The contents of serine, glycine, and alanine increased relevantly. The amount of glutamine also increased after 20 d but the amount of glutamate did not. Hence photorespiration may be stimulated under moderate NaCl stress. A relevant electron transport rate was observed under CO2-free air, which may indicate refixation of photorespiratory CO2. When NaCl accumulation proceeded for more than 20 d, photosynthesis was reduced and the content of photo-respiratory amino acids started to decrease, but the oxygenation rate did not change. and C. di Martino ... [et al.].
Rights:
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19. Photosynthetic nitrogen- and water-use efficiency of acacia and eucalypt seedlings as afforestation species

Creator:
Novriyanti, E., Watanabe, M., Makoto, K., Takeda, T., Hashidoko, Y., and Koike, T.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, afforestation, fast growing species, photosynthetic nitrogen-use efficiency, photosynthetic rate, photosynthetic water-use efficiency, 2, and 58
Language:
Multiple languages
Description:
The ecophysiological traits of acacia and eucalypt are important in assessing their suitability for afforestation. We measured the gas-exchange rate, the leaf dry mass per area (LMA) and the leaf nitrogen content of two acacia and four eucalypt species. Relative to the eucalypts, the acacias had lower leaf net photosynthetic rate (PN), lower photosynthetic nitrogen-use efficiency (PNUE), higher water-use efficiency (WUE), higher LMA and higher leaf nitrogen per unit area (N area). No clear differences were observed within or between genera in the maximum rate of carboxylation (Vcmax) or the maximum rate of electron transport (Jmax), although these parameters tended to be higher in eucalypts. PNUE and LMA were negatively correlated. We conclude that acacias with higher LMA do not allocate nitrogen efficiently to photosynthetic system, explaining why their PN and PNUE were lower than in eucalypts., E. Novriyanti ... [et al.]., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

20. Photosynthetic rate, needle longevity, and nutrient contents in Picea glehnii growing on strongly acidic volcanic ash soil in northern Japan

Creator:
Kayama, M., Satoh, F., and Koike, T.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, needle longevity, nitrogen retranslocation, nutrient physiology, photosynthetic rate, and solfatara spruce
Language:
Multiple languages
Description:
Picea glehnii Masters can grow in strongly acidic volcanic ash soil (pH 3.6) in northern Japan. We compared needle longevity, photosynthetic rate, and concentrations of elements in needles, in mature trees of P. glehnii growing in volcanic ash soil and in brown forest soil (pH 5.4). P. glehnii growing in volcanic ash soil showed suppressed photosynthetic rate and growth by the deficiency in nitrogen compared with its growth in brown forest soil. However, the younger needles of P. glehnii growing in volcanic ash soil maintained a high photosynthetic rate, as a result of large amounts of remobilized nitrogen from senesced needles. Needles of P. glehnii growing in volcanic ash soil did not show deficiencies in Ca, Mg, or K. Moreover, Al was at low levels in the needles, suggesting that P. glehnii was able to avoid Al toxicity by Al exclusion. P. glehnii thus exhibits great ability to adapt to an acidic environment. and M. Kayama, F. Satoh, T. Koike.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public