Author/Editor		Kržič, Nina; Gaberščik, Alenka; Germ, Mateja
Title		The phenotypic plasticity of Glyceria fluitans growing over the water/land gradient
Type		članek
Source		Acta Biol Slov
Vol. and No.		Letnik 47, št. 2
Publication year		2004
Volume		str. 65-73
Language		eng
Abstract		The amphibious species Glyceria fluitans successfully thrives in an intermittent ecosystem Lake Cerknica, where floods alternate with dry periods. The species grows over the environmental gradient from open water to dry land. The plant's phenotypic plasticity was studied analysing anatomical, morphological, biochemical and physiological characteristics in specimens from different locations. Floating leaves were thicker, having abundant aerenchyma, lower chlorophyll a+b contents and higher chlorophyll a/b ratio. The relative amounts of total UV-B and UV-A screening compounds per leaf area were high and similar in all forms that indicated possibly saturated amounts. The measurement of fluorescence parameters revealed no disturbance in energy harvesting since the values of potential and effective photochemical efficiencies, photochemical and non-photochemical quenching were similar over the gradient.
Summary		Amfibijska vrsta Glyceria fluirans se pojavlja v presihajočem ekosistemu Cerkniškega jezera, kjer se poplave izmenjujejo s sušnimi obdobji. Vrsta porašča širok pas na prehodu iz vode na kopno. Na podlagi nekaterih anatomskih, morfoloških, biokemijskih in fizioloških analiz rastlin na prehodu smo ugotavljali fenotipsko plastičnost vrste. Plavajoči listi so bili debelejši, z obsežnejšim aerenhimom, nižjo vsebnostjo klorofila a+b in višjim razmerjem med klorofiloma a in b. Relativna vsebnost UV-B in UV-A zaščitnih snovi na listno površino se med proučevanimi oblikami ni bistveno razlikovala kar kaže na saturirane vrednosti. Izmerjeni parametri fluorescence so odražali nemoten privzem energije, saj so bile vrednosti potencialne in dejanske fotokemične učinkovitosti ter fotokemičnega in nefotokemičnega dušenja podobne na celotnem prehodu iz vode na kopno.
Descriptors		FRESH WATER ECOSYSTEM PLANTS CHLOROPHYLL ULTRAVIOLET RAYS