Effect of drought stress and Glomus inoculation on selected physiological processes of sweet pepper (Capsicum Annuum L. CV.'Slávy')

Abstract

Sweet pepper (Capsicum annuum L. 'Slávy' F1) plants were colonized by the vesicular-arbuscular mycorrhizal fungus Glomus and grown in two irrigational levels: 1. optimal water supply (the irrigation activation by available water capacity (AWC) < 65 %); 2. drought stress (irrigation activation by AWC < 45 %). In the field experiment selected physiological parameters, such as photosynthetic rate, transpiration rate, stomatal conductance and water use efficiency were observed. The highest photosynthetic activity was observed in the first measuring date in both experimental years (2010: 7.5-8.1 μmol. m-2.s-1 2011: 6.1-8.6 μmol.m-2.s-1). In the next measuring dates, when the temperature decreased and the plants were older stage, the activity of leaves decreased. The inoculation by Glomus species had not clear effect. The inoculation did not increased the activity of plants (photosynthesis, transpiration) under optimal water supply conditions. However, based on results from 2011, under drought stress the inoculation had slightly positive effect on the photosynthetic rate. Under drought stress conditions, the water use efficiency (WUE) of plants increased slightly by the Glomus inoculation (from 4.7 to 5.1 μmol CO2. mmol H2O-1).