Effects of UV radiation and drouhgt on the accumulation of UV-screening compounds and photosynthetic parameters in selected herbs and grasses of the mountain grassland ecosystem

0423696 - ÚVGZ 2014 RIV CZ eng C - Konferenční příspěvek (zahraniční konf.)
Klem, Karel - Holub, Petr - Urban, Otmar - Rajsnerová, Petra - Kubásek, Jiří
Effects of UV radiation and drouhgt on the accumulation of UV-screening compounds and photosynthetic parameters in selected herbs and grasses of the mountain grassland ecosystem.
Global Change and Resilience: From Impacts to Responses : Proceedings of the 3rd annual Global Change and Resilience Conference. Brno: Global change research centre, Academy of Sciences of the Czech Republic, v. v. i, 2013 - (Stojanov, R.; Žalud, Z.; Cudlín, P.; Farda, A.; Urban, O.; Trnka, M.), s. 237-241. ISBN 978-80-904351-8-6.
[Global Change and Resilience. Brno (CZ), 22.05.2013-24.05.2013]
Grant CEP: GA ČR GA522/09/0468; GA MŠMT LD12030; GA MŠMT(CZ) ED1.1.00/02.0073; GA MŠMT(CZ) LM2010007
Institucionální podpora: RVO:67179843
Klíčová slova: uv radiation * uv-screening * photosynthetic parametrs * grassland ecosystem
Kód oboru RIV: EH - Ekologie - společenstva

The main objective of the experiment conducted on a mountain grassland ecosystem was to investigate the interactive eff ects of UV treatment and drought on the changes in accumulation of UV-screening compounds and photosynthetic parameters in selected herb (Hypericum maculatum) and grass (Agrostis tenuis) species. Th e experimental plots were manipulated using roof constructions enabling exclusion or transmission of incident precipitation and UV radiation, respectively. Generally, UV and drought treatments had a similar eff ect on the accumulation of fl avonols. UV exclusion resulted in a slight reduction of UV-screening compounds, particularly under the conditions of ambient precipitation. Likewise, drought treatment caused an increase in the accumulation of fl avonols per area unit. Under UV exclusion, drought slightly reduced the light-saturated CO2 assimilation rate (Amax) in both the species studied. Th e presence of UV radiation, however, led to less of a diff erence in Amax between [wet] and [dry] treatments. In addition to the increased induction of fl avonols, UV radiation increased water use effi ciency and alleviated thus the negative impact of drought on photosynthesis.
Trvalý link: http://hdl.handle.net/11104/0229850