CHLOROPHYLL FLUORESCENCE PARAMETERS AND CHLOROPHYLL CONTENT IN MANGROVE SPECIES GROWN IN DIFFERENT SALINITY

Abstract

Summary . Leaf chlorophyll fluorescence parameters as well as chlorophyllcontent were compared in three dominant mangrove species grown in twozones with different salinity in the Bhitarakanika National Park. The accu-mulation of dry matter and chlorophyll content in leaves decreased underhigh saline conditions. Quantification and de-convolution of chlorophyll fluo-rescence transient into several phenomenological and biophysical param-eters (JIP-test) revealed that maximum fluorescence (Fm), maximum quan-tum yield of primary photochemistry (Fv/Fm), area above the fluorescencecurve between Fo and Fm, electron transport and active reaction centers percross section decreased in the leaves of all species at high saline ambiencecompared to the low salinity zone. In contrast, a significant increase in theminimal fluorescence (Fo) was noticed in the leaves of A. officinalis and H.fomes in the highly saline zones. Among the fluorescence parameter studied,the area above the fluorescence curve between Fo and Fm was found to bemore sensitive to salinity. Thus, salinity induced functional alterations in PSII and led to down-regulation of PS II activity.