Stomatal and chlorophyll fluorescence characteristics in European beech cultivars during leaf development

Abstract

Changes in stomatal and chlorophyll fluorescence characteristics were analyzed in the course of leaf expansion in European beech (Fagus sylvatica L.) cultivars Aurea Pendula, Cristata, Rohanii, Rotundifolia and Viridivariegata. Stomatal length increased gradually from the second to the fifth phenological stage. Rotundifolia reached the highest mean stomatal length whereas Aurea Pendula and Cristata had the lowest values. Stomatal density for all cultivars decreased from the second to the fifth stage. Aurea Pendula reached the highest stomatal density in all phenological stages. The highest values of variable to maximum fluorescence ratio (Fv/Fm) were recorded in Rotundifolia, Rohanii, and the wild type, whereas Viridivariegata showed the lowest Fv/Fm. Similar trend was found in maximum to initial fluorescence ratio (Fm/F0), but extremely low Fm/F0 values were recorded in Viridivariegata in the last phenological stage. The highest potential electron capacity was found in Rohanii, Viridivariegata and the wild type and lowest in Cristata. This parameter increased in the course of early leaf development. © 2008 Springer Science+Business Media B.V.