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272. Tyrolské jezero Achensee - jeho krása v minulosti a dnes

Creator:
Jarmila Kubíková
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Botanika, jezera, flóra, Tyrolsko (Rakousko), 2, and 58
Language:
Czech
Description:
This article refers to the rich vegetation on the rocky slopes along the Achensee (Tyrol, Northern calcareous Alps, Karwendelalpen) described by Professor Anton Kerner 150 years ago. The vegetation today is much less diverse, the subalpine species abundant in the last centuries are absent while the species of mixed mountainous forest prevail. The abundance of the Heather (Calluna vulgaris), which was not mentioned by A. Kerner, may indicate acidification due to acid rain. And the retreat of subalpine species may indicate the on going change to a warmer climate. and Jarmila Kubíková.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

273. Úloha rostlin v epidemiích způsobovaných toxigeními kmeny střevní bakterie Escherichia coli

Creator:
Václav Kůdela
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Botanika, epidemie, rostliny, střevní bakterie, Escherichia coli, 2, and 58
Language:
Czech
Description:
A large outbreak of haemolytic uraemic syndrome and bloody diarrhoea caused by the pathogenic E. coli strain in Germany in 2011 has increased attention to foodborne diseases – bacterial infections linked to the consumption of fresh produce. Since the early 1990s, evidence is emerging that en - teropathogenic bacteria have the ability to grow and persist on crop plants for prolonged periods of time, including until harvest, and to be the carrier of illness. and Václav Kůdela.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

274. Unintended effects of genetic transformation on photosynthetic gas exchange, leaf reflectance and plant growth properties in barley (Hordeum vulgare L.)

Creator:
Sun, C. X., Yuan, F., Zhang, Y. L., Cui, Z. B., Chen, Z. H., Chen, L. J., and Wu, Z. J.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, genetic modification, leaf area, light-use efficiency, reflectance index, reflectance spectra, stomatal limitation, transgenic plants, water-use efficiency, 2, and 58
Language:
Multiple languages
Description:
Characterization of different component processes of photosynthesis is useful to understand the growth status of plants and to discover possible unintended effects of genetic modification on photosynthesis in transgenic plants. We focused on the changes in photosynthetic gas-exchange properties, reflectance spectra, and plant growth traits among groups of different transgenic barley T1 (TolT1) and its isogenic controls (TolNT1), TolT1, and group of its own transgenic progenies T2 (TolT2), TolNT1 and its wild type (WT), respectively. Gas-exchange measurements showed that only the net photosynthetic rate (P N) and the light-use efficiency (LUE) differed significantly between TolT1 and TolT2 with no obvious changes of other characteristics. Reflectance measurements indicated that the reflectance ratio was sensitive to identify the differences between two barley groups. Differences in reflectance expressed on an index basis depended on barley groups. The relationship between LUE and the photochemical reflectance index (PRI) at a leaf level among different barley groups of WT, TolNT1, TolT1 and TolT2 did not changed obviously. The differences in the total leaf area per plant (LA) between WT and TolNT1 as well as between TolT1 and TolT2 were significant. This study finally provided a plausible complex explanation for the unintended effects of genetic transformation on photosynthesis-related properties in barley at different levels. Furthermore, it was concluded that the photosynthesis-related properties of transgenic plants based on gas exchange, leaf reflectance, and plant growth measurements responded to the same environment in a more different way between two subsequent generations than to the processes of the gene insertion by Agrobacterium and associated tissue culture., C. X. Sun ... [et al. ]., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

275. Using combined measurements of gas exchange and chlorophyll fluorescence to investigate the photosynthetic light responses of plant species adapted to different light regimes

Creator:
Wong, S.-L., Chen, C.-W., Huang, H.-W., and Weng, J.-H.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, electron transport rate, fern, gross photosynthetic rate, light intensity, temperature, woody plant, 2, and 58
Language:
Multiple languages
Description:
One broad-leaved pioneer tree, Alnus formosana, two broad-leaved understory shrubs, Ardisia crenata and Ardisia cornudentata, and four ferns with different light adaptation capabilities (ranked from high to low, Pyrrosia lingus, Asplenium antiquum, Diplazium donianum, Archangiopteris somai) were used to elucidate the light responses of photosynthetic rate and electron transport rate (ETR). Pot-grown materials received up to 3 levels of light intensity, i.e., 100%, 50% and 10% sunlight. Both gas exchange and chlorophyll (Chl) fluorescence were measured simultaneously by an equipment under constant temperature and 7 levels (0-2,000 μmol m-2 s-1) of photosynthetic photon flux density (PPFD). Plants adapted to-or acclimated to high light always had higher light-saturation point and maximal photosynthetic rate. Even materials had a broad range of photosynthetic capacity [maximal photosynthetic rate ranging from 2 to 23 μmol(CO2) m-2 s-1], the ratio of ETR to gross photosynthetic rate (PG) was close for A. formosana and the 4 fern species when measured under constant temperature, but the PPFD varied. In addition, P. lingus and A. formosana grown under 100% sunlight and measured at different seasonal temperatures (15, 20, 25, and 30°C) showed increased ETR/P G ratio with increasing temperature and could be fitted by first- and second-order equations, respectively. With this equation, estimated and measured PG were closely correlated (r2 = 0.916 and r2 = 0.964 for P. lingus and A. formosana, respectively, p<0.001). These equations contain only the 2 easily obtained dynamic indicators, ETR and leaf temperature. Therefore, for some species with near ETR/PG ratio in differential levels of PPFD, these equations could be used to simulate dynamic variation of leaf scale photosynthetic rate under different temperature and PPFD conditions., S.-L.. Wong ... [et al.]., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

278. Václav Havel a příroda

Creator:
Jan Sokol
Format:
print
Type:
article, články, model:article, and TEXT
Subject:
Botanika, Havel, Václav, 1936-2011, příroda, 2, and 58
Language:
Czech
Description:
Havel’s perception of nature does not in - volve a scientific interest in its mystery and beauty, he suspected science of ultimately aiming to just utilize the nature. Nature is above all the endangered victim of the man’s unscrupulousness and exploitation. Hence Havel highlights landscape rather than nature in his texts. When he talks about nature protection, he also includes landscapes, villages and settlements, he often speaks about lapses with regard to present-day urbanism, and about human pride towards the environment. In contrast, he advocates reverence and respect for „nature, land and the historical heritage“. and Jan Sokol.
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

280. Variations in leaf respiration across different seasons for Mediterranean evergreen species

Creator:
Catoni, R., Varone, L., and Gratani, L.
Format:
bez média and svazek
Type:
model:article and TEXT
Subject:
botanika, botany, drought, leaf respiration, Mediterranean evergreen species, water stress, 2, and 58
Language:
Multiple languages
Description:
Leaf respiration (R L) of evergreen species co-occurring in the Mediterranean maquis developing along the Latium coast was analyzed. The results on the whole showed that the considered evergreen species had the same R L trend during the year, with the lowest rates [0.83 ± 0.43 μmol(CO2) m-2 s-1, mean value of the considered species] in winter, in response to low air temperatures. Higher R L were reached in spring [2.44 ± 1.00 μmol(CO2) m-2 s-1, mean value] during the favorable period, and in summer [3.17 ± 0.89 μmol(CO2) m-2 s-1] during drought. The results of the regression analysis showed that 42% of R L variations depended on mean air temperature and 13% on total monthly rainfall. Among the considered species, C. incanus, was characterized by the highest R L in drought [4.93 ± 0.27 μmol(CO2) m-2 s-1], low leaf water potential at predawn (Ψpd = -1.08 ± 0.18 MPa) and midday (Ψmd = -2.75 ± 0.11 MPa) and low relative water content at predawn (RWCpd = 80.5 ± 3.4%) and midday (RWCmd = 67.1 ± 4.6%). Compared to C. incanus, the sclerophyllous species (Q. ilex, P. latifolia, P. lentiscus, A. unedo) and the liana (S. aspera), had lower R L [2.72 ± 0.66 μmol(CO2) m-2 s-1, mean value of the considered species], higher RWCpd (91.8 ± 1.8%), RWCmd (82.4 ± 3.2%), Ψpd (-0.65 ± 0.28 MPa) and Ψmd (-2.85 ± 1.20 MPa) in drought. The narrow-leaved species (E. multiflora, R. officinalis, and E. arborea) were in the middle. The coefficients, proportional to the respiration increase for each 10°C rise (Q10), ranging from 1.49 (E. arborea) to 1.98 (A. unedo) were indicative of the different sensitivities of the considered species to air temperature variation., R. Catoni, L. Varone, and L. Gratani., and Obsahuje bibliografii
Rights:
http://creativecommons.org/licenses/by-nc-sa/4.0/ and policy:public

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