Photosynthetic activity of red and green leaf sectors in Coleus blumei plants as sensed by chlorophyll fluorescence

Abstract

The changes and responses in the chlorophyll (Chl) fluorescence (ChlF) components were studied on the red and green parts of leaves in three Coleus blumei varieties under different light intensities. Chl a, carotenoids (Car), and SPAD were linearly, positively, and significantly correlated with total Chl [i.e., Chl (a+b)] of red and green leaves. Significant differences in Chl and Car contents were noted between differentially pigmented sectors of the leaf, but no anthocyanin content was found in the green parts compared to red leaves. Values of minimal and maximal fluorescence yields in dark- and light-adapted states in both red and green leaves were all positively and significantly correlated with Chl contents under dark conditions and all PPFD treatments for 20 min. Assessing the ChlF parameters under PPFD variations is an important tool for finding improved photosynthetic productivity of plants.

Keywords

• light intensity; light response; photosynthetic efficiency; photosynthetic photon flux density.