This paper reports the effects of selenium (Se) application on some physiological characteristics of barley (Hordeum vulgare L. cv. Rihane-03) exposed to drought stress. Foliar application to barley ...at 30 g selenium ha-1, as sodium selenate, increased significantly shoot dry weight and relative water content in well-watered plants. A remarkable reduction in dry weight of water-stressed plants was associated with significant decrease in maximal efficiency of PSII (Fv/Fm), stomatal conductance (gs) and net CO2 assimilation rate (A). Activity of antioxidant enzymes was increased by drought stress significantly. Amounts of malondialdehyde (MDA) and hydrogen peroxide (H2O2) remained unchanged in Sesupplemented water-deficit plants obviously because of an efficient scavenging following significant enhancement of catalase (CAT) and glutathione peroxidase (GSH-Px) activities. These results indicate that an application of selenium was favorable for biomass accumulation of barley plants under well-watered conditions. However, it did not significantly affect dry matter accumulation under drought stress, but Se-supplemented water-deficit plants exhibited better protection from oxidative damage because of higher CAT and GSH-Px activities and lower level of lipid peroxidation. These results suggest that selenium application can improve antioxidant defense system under drought stress conditions, and it may be recommended for arid and semiarid regions.
E. A. Lysenko.
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The rapid light curve method is a time-saving approach to the measurement of photosynthetic processes over a wide spectrum of light intensities. The ...adaptation to darkness enables the calculation of a complete set of coefficients for chlorophyll (Chl) fluorescence and P700 light absorption; however, dark-adapted plants demonstrate drastically different patterns of Chl fluorescence than that of light-adapted plants. The present work compared light-adapted barley plants without dark adaptation (L), and barley plants adapted to darkness and readapted to light for 7.5 min (D/L). The rapid light curves were generally similar in both the L and D/L variants. Some differences between the L and D/L variants were found in plants grown at any illumination. A number of distinctions between the L and D/L variants were characteristic of plants grown under particular illumination levels. The present analysis demonstrated that the scheme including dark adaptation and short readaptation to light (D/L) enabled to obtain generally correct data.
L. Begović, V. Galić, I. Abičić, Z. Lončarić, A. Lalić, and S. Mlinarić.
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This study aimed to explore how ten selected winter barley genotypes responded to variations in ...environmental conditions during the growth season by using fast chlorophyll a fluorescence and normalized difference vegetation index (NDVI) at the booting, anthesis and early grain-filling stage. Lower amount of rainfall during the anthesis induced instability in the function of PSII, observed as the positive K-band in six and the positive L-band in seven genotypes. At grain filling, all genotypes displayed negative K- and L-bands, suggesting an increase of stability within PSII. The performance index increased from booting to grain filling in most genotypes. Chlorophyll a fluorescence parameters were incorporated into the partial least squares model as explanatory variables of NDVI. After a cross-validation, the model with four latent variables was chosen explaining 75.8% variance (r = 0.870) for NDVI. The principal component analyses showed two distinct types of the reaction of the barley genotypes to the mild drought stress at anthesis.
T. Istanbuli, M. Baum, H. Touchan, and A. Hamwieh.
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Drought stress is one of the major constraints limiting the production and productivity of barley. We tried to ...identify some indicators related to plant productivity by analyzing some agro-morphological and physiological traits in recombinant inbred lines (RILs). Plants were exposed to three water treatments: well-watered at 70% available water content (AWC), mild drought stress at 35% AWC, and severe drought stress at 10% AWC. Our results revealed that drought significantly affected most of the studied morpho-physiological traits resulting in strong decreases in yield and the studied traits. We did not observe a significant difference in water-use efficiency between severe and mild drought conditions. Therefore, the mild stress treatment was considered as the most suitable water level in our study. Genotypes with the most tillers and spikes, the highest 1,000-grain mass, and biological yields achieved higher grain yields under all water stress conditions. Therefore, these traits could be considered as useful tools in breeding programs.
F. Bahrami, A. Arzani and M. Rahimmalek.
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Terminal heat stress is one of the major constraints of cereal production. A two-year field investigation was performed to ...assess the response of Hordeum vulgare ssp. spontaneum genotypes to terminal heat stress using gas-exchange parameters, photosystem efficiency, proline accumulation, cell membrane leakage, and grain yield traits. Results of analysis of variance revealed the significant effects of heat stress (E), genotype (G), and G × E on the studied traits. The results of linear regression analysis showed that yield loss was inversely correlated with the maximum quantum yield of PSII photochemistry (Fv/Fm) and chlorophyll content. Path-coefficient analysis revealed that high Chl contents were either directly related to the grain yield or indirectly through the higher net photosynthetic rate and higher Fv/Fm values under high temperatures at the reproductive growth stage. Overall, the adapted wild genotypes exhibited physiological mechanisms capable of sustainable maintaining their yield capacity and plasticity flow, which could be exploited by crossing with cultivated barley to introgress heat tolerance.
Sestavili Vladimír Čihák, Bohdan Erben, Adolf Ernest, dr. Karel Holý, dr. Jan Jelínek, dr. Jos. Munzar, Karel Procházka, dr. Julius Stoklasa a Eugen Vítek
Josef Slabý
Zvl. otisk úvod. článku výstav. katalogu Ústř. společnosti hospod. pro král. české v Praze r. 1902
Josef Slabý
Zvl. otisk úvod. článku výstav. katalogu Ústř. společnosti hospod. pro král. ...české v Praze r. 1902
Josef Slabý
Zvl. the imprint of the introduction. an article of exhibitions. the Ústí catalog. companies of pubs. for the king. Czech in Prague 1902
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