Research by the Masaryk University in Siberia is focused on ecosystems similar to Central European palaeoecosystems of the Pleistocene and Early Holocene. We mainly deal with the diversity and productivity of plant communities and their relationships to indicators of past environments (pollen deposition, mollusc assemblages). The results indicate that the best analogues of Pleistocene ecosystems are found in the Altai-Sayan region of southern Siberia. and Milan Chytrý.
Broomcorn millet (Panicum miliaceum L.) is one of the important C4 crops in the semiarid regions of northern China. It is a close relative of biofuel crop switchgrass. Yet, there is no information on how these crops might respond to a climate change in China. In order to gain insight into such a response, we studied the effect of elevated CO2 concentration (EC) on broomcorn millet. The changes in leaf photosynthesis, chlorophyll fluorescence, morphological parameters, biomass and yield in response to EC [i.e., + 200 µmol(CO2) mol-1] over two years were determined at the open-top chamber (OTC) experimental facility in north China. EC increased net photosynthetic rate, stomatal conductance, intercellular CO2 concentration, transpiration rate, instantaneous transpiration efficiency, effective quantum yield of PSII photochemistry, and photochemical quenching coefficient of fully expanded flag leaves. Maximal quantum yield of PSII photochemistry declined under EC in 2013, but was not affected in 2014. EC significantly decreased intrinsic efficiency of PSII in 2013, but increased in 2014. Leaf nonphotochemical quenching decreased under EC both in 2013 and 2014. EC significantly enhanced the aboveground biomass and yield by average of 31.4 and 25.5% in both years, respectively. The increased yield of broomcorn millet under EC occurred due to the enhanced number of grains per plant. We concluded that photosynthesis of broomcorn millets was improved through increased stomatal conductance in leaves under EC, which led to an increase in height, stem diameter, aboveground biomass, and yield. This study extends our understanding of the response of this ancient C4 crop to elevated CO2 concentration., X. Y. Hao, P. Li, H. Y. Li, Y. Z. Zong, B. Zhang, J. Z. Zhao, Y. H. Han., and Obsahuje bibliografii
The effect of drought stress on energy dissipation and antioxidant enzyme system in two sweet sorghum inbred lines (M-81E and Roma) was investigated. Results showed that the germination indicator increased more in M-81E than that in Roma under rehydration. Under drought stress, both the maximal photochemical efficiency of PSII (Fv/Fm) and oxidoreductive activity (ΔI/I0) of Roma decreased more than those in M-81E. Relative to Fv/Fm, the ΔI/I0 decreased markedly, which indicated that PSI was more sensitive to drought stress than PSII. Increases in the reduction state of QA (1-qp), nonphotochemical quenching (NPQ) and minimal fluorescence yield of the dark-adapted state (F0) were greater in Roma than those in M-81E; meanwhile, the H2O2 content was lower in M-81E than that in Roma. Our results suggested that the photoinhibition might be related to the accumulation of reactive oxygen species (ROS). The antioxidant enzyme system and energy dissipation of M-81E could respectively increase drought tolerance by eliminating ROS and excess energy more efficiently than that of Roma., Y. Y. Guo, S. S. Tian, S. S. Liu, W. Q. Wang, N. Sui., and Obsahuje bibliografii
We studied how tomato (Lycopersicon esculentum Mill.) chloroplast omega-3 fatty acid desaturase gene (Lefad7) overexpression enhanced low-temperature (LT) tolerance in transgenic tomato plants. In these plants, the content of linolenic acid (18:3) markedly increased and, correspondingly, the content of linoleic acid (18:2) decreased. Similar changes were found after 6 h under LT (4°C) treatment. Under LT stress, wild type (WT) tomato plants showed a much greater increase in relative electrolyte leakage and malondialdehyde (MDA) contents compared with transgenic plants. Transgenic plants exhibited higher activities of antioxidative enzymes and a lower content of reactive oxygen species (ROS). Transgenic plants maintained a relatively higher level of the net photosynthetic rate (PN) and chlorophyll (Chl) content than WT plants under LT stress. Taken together, we suggested that overexpression of Lefad7 enhanced LT tolerance by changing the composition of membrane lipids in tomato plants, with the increased content of trienoic fatty acids and reduced content of dienoic fatty acids that led to series of physiological alterations., X. Y. Liu ... [et al.]., and Obsahuje bibliografii
Článek přináší poznatky o vznikajících mezidruhových vztazích v ekosystémech po zavlečení nového invazního druhu rostliny – netýkavky žláznaté (Impatiens glandulifera) – a uvádí některé entomologické aspekty jejího masového výskytu v novém prostředí., The impact of aphids on the invasive plant Impatiens glandulifera in the Czech Republic is shown and some entomological aspects of I. glandulifera distribution in local ecosystems are discussed., and Petr Starý, Jan Havelka.