The temperature dependence of the relationship between the decline in activity of photosystem II (PSII) and a chlorophyll a fluorescence parameter combining the excitation pressure (1-qP) and efficiency of excitation energy capture by open PSII reaction centers in the light-acclimated state (Fv'/Fm') was investigated in cotton leaves. A formula for the prediction of PSII inactivation is propose...

(Chlorophyll fluorescence parameters in populations of two legume trees: Stryphnodendron adstringens (Mart.) Coville (Mimosoideae) and Cassia ferruginea (Schrad.) Schrad. ex DC. (Caesalpinoideae)). The aim of this study was to investigate the photosynthetic performance in populations of two legume tree species, Stryphnodendron adstringens (Mimosoideae), typical from Cerrado, and Cassia ferrugin...

The effects of soil drought on photosynthesis and chlorophyll fluorescence in the leaves of three bean (Phaseolus vulgaris L.) genotypes were studied. Drought was imposed 14 days after plants growing up. In the primary leaf of all the cultivars, water stress led to a noticeable decrease in both the initial slope of the An/Ci curve and Amax. The most strongly marked reduction in leaf CO2 exchang...

The viability of algae belonging to divisions Cyanophyta, Chlorophyta and Xantophyta has been assessed by chlorophyll autofluorescence and after staining with fluorescent dyes rodamin B, neutral rot, calcofluor white and fluorescein diacetate. For this purpose the fluorescence of algal cells from fresh and old cultures was scored. It was established that chlorophyll autofluorescence could be re...

A characteristic spectral emission is observed in vegetation chlorophyll under excitation by solar radiation. This emission, known as solar-induced chlorophyll fluorescence, occurs in the red and near infra-red spectral regions. In this paper a new methodology for the estimation of solar-induced chlorophyll fluorescence from spaceborne and airborne sensors is presented. The fluorescence signal ...

1. Aqueous extracts of spinach and Aspidistra leaves yield highly opalescent preparations which are not in true solution. Such extracts differ markedly from colloidal chlorophyll in their spectrum and fluorescence. The differences between the green leaf pigment and chlorophyll in organic solvents are shown to be due to combination of chlorophyll with protein in the leaf. 2. The effect of some a...

We investigated changes in chlorophyll a fluorescence from alternate leaf surfaces to assess the intraleaf light acclimation patterns in combination with natural variations in radiation, leaf angles, leaf mass per area (LMA), chlorophyll content (Chl) and leaf optical parameters. Measurements were conducted on bottom- and top-layer leaves of Tilia cordata Mill. (a shade-tolerant sub-canopy spec...