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12. Photosynthetic response of tetraploid and hexaploid wheat to water stress
- Creator:
- Li, Y. P., Li, Y. Y., Li, D. Y., Wang, S. W., and Zhang, S. Q.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- pšenice, wheat, izotopy uhlíku, enzymové aktivity, vodní stres, tetraploidy, hexaploidy, carbon isotope, ear photosynthesis, enzyme activities, water relations, water stress, tetraploids, hexaploids, 2, and 581
- Language:
- Multiple languages
- Description:
- Photosynthetic characteristics of ear and flag leaves of wheat species, tetraploid Triticum dicoccoides Kom and hexaploid Bima1, were studied in plants grown under well-watered (WW) and water-stressed (WS) conditions. Compared to ears, flag leaves exhibited higher photosynthetic rate (PN) at the filling stage, but more severe decrease under WS. PN in the tetraploid wheat ear remained higher than that in the hexaploid wheat during the grain-filling stage. Water stress decreased PN in both the organs; this decline was caused by a reduction in Rubisco activity, not by drought-induced stomatal limitation. Tetraploid wheat ears exhibited higher relative water content and water-use efficiency than that of hexaploid wheat, under WS. The change in phosphoenolpyruvate carboxylase activity and carbon isotope composition indicated the absence of C4 metabolism in the ears of both species under both conditions. The improved performance of the tetraploid wheat ears under WS was associated with better water relations., Y. P. Li, Y. Y. Li, D. Y. Li, S. W. Wang, S. Q. Zhang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
13. Photosynthetic responses of wheat (Triticum aestivum L.) to combined effects of drought and exogenous methyl jasmonate
- Creator:
- Ma, C., Wang, Z. Q., Zhang, L. T., Sun, M. M., and Lin, T. B.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, pšenice, photosynthesis, wheat, antioxidant enzyme, gas exchange, stomatal behavior, water stress, methyl jasmonate, Triticum aestivum L, 2, and 581
- Language:
- Multiple languages
- Description:
- Drought stress limits wheat growth and productivity. The response of wheat (Triticum aestivum L.) to different water supply conditions (well-watered and drought-stressed) and exogenous methyl jasmonate (MeJA; 0 and 0.25 μM) was studied. The application of MeJA enhanced wheat adaptability to drought stress by physiological and metabolic adjustments. Drought stress reduced net photosynthetic rate (PN), stomatal conductance (gs), transpiration rate (E), and water-use efficiency (WUE) in wheat. The application of exogenous MeJA decreased also gs and E, but stimulated WUE. Meanwhile, MeJA mitigated the decline of PN, gs, and WUE induced by drought stress and midday depression by 6-183%. Both drought stress and exogenous MeJA induced stomatal closure, which improved water status and delayed plant senescence. MeJA enhanced the activities of superoxide dismutase, peroxidase, catalase, and reduced malondialdehyde content. PN-PAR response curves showed that MeJA mitigated the decline of maximum PN, apparent quantum yield, and saturation irradiance, and the increase of compensation irradiance. Drought stress and exogenous MeJA increased dark respiration rate and showed an additive effect. These results indicated that 0.25 μM MeJA enhanced the photosynthesis under drought stress mainly by improving the water status and antioxidant capacity of wheat., C. Ma, Z. Q. Wang, L. T. Zhang, M. M. Sun, T. B. Lin., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
14. Physiological response of wheat varieties to elevated atmospheric CO2 and low water supply levels
- Creator:
- Bencze, S., Bamberger, Z., Janda, T., Balla, K., Varga, B., Bedõ, Z., and Veisz, O.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, sucha, pšenice, photosynthesis, dry atmosphere, wheat, antioxidant enzyme system, bread wheat, CO2 enrichment, drought, Triticum aestivum, 2, and 581
- Language:
- Multiple languages
- Description:
- In the phytotron experiment, the effect of elevated atmospheric CO2 (EC, 750 μmol mol-1) on the drought tolerance was studied in two winter varieties (Mv Mambo, tolerant; Mv Regiment, moderately tolerant) and in one spring variety of wheat (Lona, sensitive to drought). Changes in net photosynthetic rate (P N), stomatal conductance, transpiration, wateruse efficiency, effective quantum yield of photosystem II, and activities of glutathione reductase (GR), glutathione-Stransferase (GST), guaiacol peroxidase (POD), catalase (CAT), and ascorbate peroxidase (APX) were monitored during water withdrawal. Drought caused a faster decline of PN at EC, leading to the lower assimilation rates under severe drought compared with ambient CO2 (NC). In the sensitive variety, PN remained high for a longer period at EC. The growth at EC resulted in a more relaxed activation level of the antioxidant enzyme system in all three varieties, with very low activities of GR, GST, APX, and POD. The similar, low values were due to decreases in the varieties which had higher ambient values. A parallel increase of CAT was, however, recorded in two varieties. As the decline in PN was faster at EC under drought but there was no change in the rate of electron transport compared to NC values, a higher level of oxidative stress was induced. This triggered a more pronounced, general response in the antioxidant enzyme system at EC, leading to very high activities of APX, CAT, and GST in all three varieties. The results indicated that EC had generally favourable effects on the development and stress tolerance of plants, although bigger foliage made the plants more prone to the water loss. The relaxation of the defence mechanisms increased potentially the risk of damage due to the higher level of oxidative stress at EC under severe drought compared with NC., S. Bencze, Z. Bamberger, T. Janda, K. Balla, B. Varga, Z. Bedõ, O. Veisz., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
15. Response of photosystem II performance and antioxidant enzyme activities in stay-green wheat to cytokinin
- Creator:
- Yang, D. Q., Luo, Y. L., Dong, W. H., Yin, Y. P., Li, Y., and Wang, Z. L.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- růstový hormon, pšenice, growth hormone, wheat, chlorofylová fluorescence, výměna plynu, JIP test, index výkonnosti, peroxidáza, cytokininy, chlorophyll fluorescence, gas exchange, performance index, peroxidase, cytokinin, 2, and 581
- Language:
- Multiple languages
- Description:
- WN6 (a stay-green wheat cultivar) and JM20 (control) were used to evaluate the effects of exogenous cytokinin on photosynthetic capacity and antioxidant enzymes activities in flag leaves. Results showed that WN6 reached the higher grain mass, which was mainly due to the higher photosynthetic rate resulting from the higher maximal quantum yield of PSII photochemistry (ΦPSII) and probability that a trapped exaction transfers an electron into the electron transport chain beyond QA (Ψo), and lower relative variable fluorescence intensity at the J-step (Vj). Exogenous 6-benzylaminopurine (6-BA) enhanced antioxidant enzymes activities and decreased malondialdehyde (MDA) content. Enhanced Ψo and electron transport rate (ETR), and decreased Vj contributed to improved photosynthetic rate in the 6-BA treatment. In addition, exogenous 6-BA significantly increased endogenous zeatin (Zt) content, which was significantly and positively correlated with the antioxidant enzyme activity and ΦPSII, implying that higher Zt content was responsible for the improved antioxidant status and photosynthetic performance., D. Q. Yang, Y. L. Luo, W. H. Dong, Y. P. Yin, Y. Li, Z. L. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
16. Severe water deficit-induced ethylene production decreases photosynthesis and photochemical efficiency in flag leaves of wheat
- Creator:
- Yang, W., Yin, Y., Jiang, W., Peng, D., Yang, D., Cui, Y., and Wang, Z.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, ethylen, pšenice, photosynthesis, ethylene, wheat, 1-aminocyclopropane-1-carboxylic acid, chlorophyll fluorescence, net photosynthetic rate, severe water deficit, Triticum aestivum L., 2, and 581
- Language:
- Multiple languages
- Description:
- Wheat (Triticum aestivum L.) cv. Jimai22 was used to evaluate the effect of ethylene evolution rate (EER) and 1-aminocyclopropane-1-carboxylic acid (ACC) and their relations with photosynthesis and photochemical efficiency in plants well-watered (WW) and under a severe water deficit (SWD). SWD caused a noticeable reduction in the grain mass. The marked increases in both EER and the ACC concentration were observed under SWD; it was reversed effectively by exogenous spermidine (Spd) or amino-ethoxyvinylglycine (AVG). Thermal images indicated that SWD increased obviously the temperature of flag leaves, mainly due to the decrease in transpiration rate under SWD. Exogenous Spd or AVG decreased to some extent the temperature of the flag leaves. The strong decline in photosynthetic rate (PN) and stomatal conductance as well as the photodamage of PSII were also observed under SWD after 14 and 21 days after anthesis (DAA). Intercellular CO2 concentration was reduced at 7 DAA, but slightly increased at 14 and 21 DAA under SWD, indicating that the decreased PN at 7 DAA might result from stomatal limitations, while the decline after 14 and 21 DAA might be attributed to nonstomatal limitations. Correlation analysis suggested that EER and ACC showed negative relations to photosynthesis and photochemical efficiency. Data obtained suggested that the effects of SWD were mediated predominantly by the increase in EER and ACC concentration, which greatly decreased the leaf photosynthesis and photochemical efficiency, and, therefore, reduced the grain mass. Application of Spd or AVG reduced the EER and ACC, and thus positively influenced photosynthesis and photochemical efficiency under SWD., W. Yang, Y. Yin, W. Jiang, D. Peng, D. Yang, Y. Cui, Z. Wang., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
17. Světová věda z Hané: Jak šlechtit plodiny budoucnosti
- Creator:
- Svoboda, Luděk
- Format:
- print, bez média, and svazek
- Type:
- article, články, journal articles, model:article, and TEXT
- Subject:
- Věda. Všeobecnosti. Základy vědy a kultury. Vědecká práce, Akademie věd České republiky, šlechtění rostlin, rostlinný genom, pšenice, plant breeding, plant genome, wheat, 12, and 00
- Language:
- Czech
- Description:
- Luděk Svoboda.
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public
18. The potential of leaf chlorophyll content to screen bread-wheat genotypes in saline condition
- Creator:
- Kiani-Pouya, A. and Rasouli, F.
- Format:
- print, bez média, and svazek
- Type:
- model:article and TEXT
- Subject:
- fotosyntéza, biomasa, chlorid sodný, chlorofyl, pšenice, photosynthesis, biomass, sodium chloride, chlorophyll, wheat, NaCl, SPAD, Triticum aestivum L, 2, and 581
- Language:
- Multiple languages
- Description:
- Physiological traits, which are positively associated with yield under salt-stress conditions, can be useful selection criteria in screening for salt tolerance. We examined whether chlorophyll (Chl) content can be used as screening criterion in wheat. Our study involved 5 wheat genotypes under both saline and nonsaline field conditions as well as in a sand-culture experiment. Salt stress reduced significantly biomass, grain yield, total Chl and both Chl a and b in all genotypes. In the sand-culture experiment, Chl accumulation was higher in PF70354/BOW, Ghods, and H499.71A/JUP genotypes at nonsaline control, moderate, and high salt concentrations, respectively. In the field experiment, genotype H499.71A/JUP belonged to those with the highest Chl density. The SPAD (Soil Plant Analysis Development) meter readings were linearly related to Chl content both in the sand-culture and in the field experiment. However, salt stress affected the calibration of SPAD meter. Therefore, separate Chl-SPAD equations were suggested for saline and nonsaline conditions. The correlation coefficients between the grain yield and SPAD were positive and significant both in the sand culture and in the field experiment. These findings suggested that SPAD readings could be used as a tool for rapid assessment of relative Chl content in wheat genotypes. It could be used for the indirect selection of high-yielding genotypes of wheat under saline condition in sand-culture and field experiments., A. Kiani-Pouya, F. Rasouli., and Obsahuje bibliografii
- Rights:
- http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public