Effect of Ecklonia maxima extract on photosynthesis activity and chlorophyll content of Medicago xvaria Martyn leaves

Jacek Sosnowski1, Kazimierz Jankowski1, Milena Truba1*, and Elżbieta Malinowska1
Recently, there is a big interest in science to use seaweed extract in agricultural practice. Therefore, the aim of this paper was to determine the effect of foliar application of Ecklonia maxima extract on photosynthetic activity and chlorophyll content of Medicago ×varia Martyn leaves. The experimental factor was a commercial product containing E. maxima extract (Em). The following parameters were determined: maximum photosystem II efficiency (Fv/Fm) in the dark-adapted state, actual photosystem II efficiency in the light-adapted state (ΔF/Fm’), the photochemical quenching coefficient (qP), the non-photochemical quenching coefficient (qN), chlorophyll content determination. The Fisher-Snedecor test was used to determine whether the impact of experimental factor was significant, while the value of the HSD0.05 was calculated with Tukey’s test. As a reaction to the particular conditions during the experiment alfalfa treated with Em had a better efficiency of the photosynthetic apparatus in relation to the control. Algae extract used on hybrid alfalfa leaves caused a 12.4% increase of Fv/Fm parameter, from 0.565 on the control to 0.635. The value of the actual efficiency of photosystem II (ΔF/Fm) determined under the same conditions turned out to be about 20% higher for plants treated with the extract. Chlorophyll a and b concentration, as a response to the extract, increased by 12% and 16.7%, respectively. The experiment showed that periods of rainfall shortages did not reverse the effect of the extract on plants, with an increase in chlorophyll a and b content during the growing seasons with dry and extremely dry months.
Keywords: Chlorophyll fluorescence, Ecklonia maxima, marine algae extract, photochemical quenching coefficient, seaweed.
1Siedlce University of Natural Sciences and Humanities, Department of Grassland and Green Areas Creation, Institute of Agronomy, Prusa 14 Street, 08-110 Siedlce, Poland.
*Corresponding author (milena.truba@uph.edu.pl).