Author/Editor		Germ, Mateja; Mazej, Zdenka; Gaberščik, Alenka; Haeder, Donat-P
Title		The influence of enhanced UV-B radiation on Batrachium trichophyllum and Potamogeton alpinus - aquatic macrophytes with amphibious character
Type		članek
Source		J Photochem Photobiol B
Vol. and No.		Letnik 66, št. 1
Publication year		2002
Volume		str. 37-46
Language		eng
Abstract		The responses of two amphibious species. Batrachium trichophyllum and Potamogeton alpinus to different UV B environments were studied. Plant material from natural environments, as well as from outdoor treatments was examined. In long-term outdoor experiments plants were grown under three different levels of UV B radiation: reduced and ambient UV B levels, and a UV B level simulating 17% ozone depletion. The following parameters were monitored: contents of total methanol soluble UV absorbing compounds and chlorophyll a, terminal eležžtron transport system (ETS) activity and optimal and effective quantum yield of photosystem II. No effect of the different UV B levels on the measured parameters was observed. The amount of UV B absorbing compounds seems to be saturated, since no differences were observed between treatments and no increase was found in peak season, when natural UV B levels were the highest. Physiological measurements revealed no harmful effects; neither on potential and actual photochemical efficiency, nor on terminal ETS acty. The contents of UV B absorbing compounds were examined also in plant material sampled in low and high altitude environments during the growth season. Both species exhibited no seasonal dynamics of production of UV absorbing compounds. The contents were variable and showed no significant differences between high and low altitude populations.
Descriptors		PLANTS ULTRAVIOLET RAYS CHLOROPHYLL ELECTRON TRANSPORT PHOTOSYNTHESIS