introduction salinity has various effects on plant growth by affecting physiological processes. the decline in plant productivity under saline condition, frequently linked with the reduction of photosynthetic capability. it has been reported that efficiency of psii photochemistry (fv/fm) of numerous plant species have been decreased due to salt stress studies have shown that salicylic acid (sa...

The changes in pigment composition, photosynthesis and PSII photochemistry were investigated in cells of Spirulina platensis adapted to salt stress (!0±75 M NaCl). A decrease in the phycocyanine}chlorophyll and no significant change in the carotenoid}chlorophyll ratio were observed in salt-adapted cells. Salt stress inhibited the apparent quantum efficiency of photosynthesis and PSII activity w...

many phragmites-dominated wetlands have been markedly salinized and alkalinized in the songnen plain, northeastern china. agricultural wastewater with high nitrogen content has been discharged into these alkalinized-salinized wetlands. to understand the effect of salinity-alkalinity on reed (phragmites australis) seedlings at various nitrogen levels, we examined photosynthesis rate, chlorophyll...

Photosynthetic gas exchange, modulated chlorophyll fluorescence, rapid fluorescence induction kinetics, and the polyphasic fluorescence transients were used to evaluate PSII photochemistry in the halophyte Suaeda salsa exposed to a combination of high salinity (100-400 mM NaCl) and heat stress (35-47.5 degrees C, air temperature). CO(2) assimilation rate increased slightly with increasing salt ...

Plectonema boryanum UTEX 485 cells were grown at 29 degrees C and 150 mumol m-2 s-1 photosynthetically active radiation (PAR) and exposed to PAR combined with ultraviolet-A radiation (UV-A) at 15 degrees C. This induced a time-dependent inhibition of photosystem II (PSII) photochemistry measured as a decrease of the chlorophyll a fluorescence ratio, Fv/Fm, to 50% after 2 h of UV-A treatment com...

The extent to which PSII photoinactivation affects electron transport (PhiPSII) and CO2 assimilation remains controversial, in part because it frequently occurs alongside inactivation of other components of photosynthesis, such as PSI. By manipulating conditions (darkness versus low light) after a high light/low temperature treatment, we examined the influence of different levels of PSII inacti...

The stability of PSII in leaves of the resurrection plant Haberlea rhodopensis to high temperature and high light intensities was studied by means of chlorophyll fluorescence measurements. The photochemical efficiency of PSII in well-hydrated Haberlea leaves was not significantly influenced by temperatures up to 40 degrees C. Fo reached a maximum at 50 degrees C, which is connected with blockin...

The use of chlorophyll fluorescence to monitor photosynthetic performance in algae and plants is now widespread. This review examines how fluorescence parameters can be used to evaluate changes in photosystem II (PSII) photochemistry, linear electron flux, and CO(2) assimilation in vivo, and outlines the theoretical bases for the use of specific fluorescence parameters. Although fluorescence pa...

Apple scab causes significant losses in the production of this fruit. A timely and more site-specific monitoring and spraying of the disease could reduce the number of applications of fungicides in the fruit industry. The aim of this leaf-scale study therefore lies in the early detection of apple scab infections in a non-invasive and non-destructive way. In order to attain this objective, fluor...