The effects of foliar spraying of the dithiocarbamate zineb on two cultivars of tomato grown in the field in a site with high ozone concentrations were studied by means of biomass assessment, antioxidant enzyme assays, lipid peroxidation, and chlorophyll fluorescence measurements. Zineb prevented the peroxidation of membrane lipids and decreased the activity of scavenging enzymes, which suggests that plants sprayed with zineb are subjected to lower oxidative stress than controls. The beneficial effects of zineb protection is the utilization of a larger fraction of absorbed radiant energy in photosynthesis and a larger fruit yield in plants of both cultivars. and Á. Calatayud, E. Barreno.
The foliar stable carbon isotope compositions (δ13C) of nine dominant species in seven sites, Yangling, Yongshou, Tongchuan, Fuxian, Ansai, Mizhi, and Shenmu, standing from the south to the north in the Loess Plateau of China were studied. The results showed that foliar δ13C values ranged from -22.61 to -30.73 ‰ with an average of -27.23 ‰ in 141 C3 plant samples collected from the Loess Plateau. Foliar δ13C values varied significantly (p<0.001) among the nine C3 species, which were Pinus tabulaeformis Carr., Robinia pseudoacacia L., Zizyphus jujuba Mill. var. spinosus Hu., Rubus parvifolius L., Hippophae rhamnoides L., Caragana korshinskii Kom., Lespedeza davurica (Laxm.) Schindl., Artemisia sacrorum Ledeb. var. incana Mattf., and Agropyron cristatum Gaertn. Comparatively, R. pseudoacacia, H. rhamnoides, and C. korshinskii had much higher δ13C values than the other six species, while A. sacrorum had the lowest δ13C value. There was no significant difference in foliar δ13C value among five species, P. tabulaeformis, Z. jujuba, R. parvifolius, L. davurica, and A. cristatum. Considering the life forms categorized from nine C3 species, trees and shrubs had significantly higher δ13C values than herbs (p<0.001). The deciduous tree R. pseudoacacia had much higher δ13C value than the evergreen tree P. tabulaeformis (p<0.01). Among the four shrubs, foliar δ13C values in H. rhamnoides and C. korshinskii were markedly higher (p<0.01) than those in Z. jujuba and R. parvifolius. Among the three herbs, L. davurica and A. cristatum had significantly higher δ13C values than A. sacrorum (p<0.01). Leguminous species such as R. pseudoacacia, C. korshinskii, and L. davurica as well as a non-leguminous species with nitrogen-fixation capacity, H. rhamnoides, had higher δ13C values than other non-leguminous species with same life-form. The mean δ13C value increased by about 7 % from Yangling in the south to Shenmu in the north as climatic drought increased, and foliar δ13C values differed much (p<0.001) among the seven sites. For nine species in the Loess Plateau, foliar δ13C values were significantly and negatively (p<0.001) correlated with the mean annual precipitation, moreover, an increase of 100 mm in annual precipitation would result in a decrease of 1.2 ‰ in δ13C value. and S.-X. Zheng, Z.-P. Shangguan.
Despite the elimination of the original forest and frequent cultivation using slash and burn, a large spread in leaf δ13C was recorded in weeds, crops, and bush fallow species, reflecting a forest environment rather than a broken canopy or open environment., A. De Rouw, J .F. Maxwell, C. Girardin., and Obsahuje bibliografii
We developed new parameters for molecular dynamics (MD) simulations, namely partial atomic charges, equilibrium bond-lengths, angles, dihedrals, atom types, and force constants of chlorophyll a (Chl) and plastoquinone (PQ), and both reduced and neutral form of primary acceptor (PHO) molecule. These parameters are essential for MD simulations that can interpret various structure functional relationships during primary processes of charge separation and stabilization in photosystem 2 reaction centres. and P. Palenčár, F. Vácha, M. Kutý.
The work described in this contribution was performed as a part of the 3AS project (Active Aeroelastic Aircraft Structures) which was funded under contract (Contract No. G4RD-CT-2002-00679) of the European Union. The paper deals with the tests of the X-DIA component aeroelastic demonstrator (the front part of the fuselage with the foreplane of the three plane jet transport aircraft) in the VZLU Prague. and Obsahuje seznam literatury