The seed progeny photosynthesis intensity and the photosynthetic apparatus state of genus Pinus species different life forms were studied in seasonal dynamics: P. sibirica is an upright tree, pumila a prostrate species. age was twelve years old. both increased from May to July, maximum July amounted 9.2 mg CO2 mg-1 fr. m. h-1 Siberian stone pine 7.8 dwarf pine, August assimilation activity bega...

Water deficiency is one of the most important environmental stresses that limit plant growth and crop production. Measurement of chlorophyll fluorescence parameters is considered as an important indicator to evaluate the photosynthetic apparatus. In the present study, the effects of regulated water deficit, investigated in four water-regimes in pistachio orchard with 12-year-old trees of Akbari...

High temperature and high light intensity is a common environment posing a great risk to organisms. This study aimed to elucidate the effects of sub-high temperature and high light intensity stress (HH, 35°C, 1000 μmol⋅m-2⋅s-1) and recovery on the photosynthetic mechanism, photoinhibiton of photosystem II (PSII) and photosystem I (PSI), and reactive oxygen (ROS) metabolism of tomato seedlings. ...

Soil waterlogging is an environmental limitation that promoted by changes in rainfall patterns and negatively affects plant physiology, growth, development, coffee production, exports Colombia. The objective of this research was to evaluate responses water status, chlorophyll fluorescence parameters for plants under different conditions. evaluations were carried out on six-month-old “Cenicafé 1...

To reveal and quantify the interactive effects of drought stresses and elevated CO2 concentration [CO2] on photochemistry efficiency of cucumber seedlings, the portable chlorophyll meter was used to measure the chlorophyll content, and the Imaging-PAM was used to image the chlorophyll fluorescence parameters and rapid light response curves (RLC) of leaves in two adjacent greenhouses. The result...

The effect of excess of cadmium (Cd) on chlorophyll fluorescence of barley seedlings was studied. The leaves were dark-adapted and then illuminated at 10 different light intensities within the range of 70–1600 μmol.m–2.s–1 photosynthetically active radiation (PAR). It was found that Cd decreases the chlorophyll fluorescence parameters in dark-adapted leaves: ground (Fo), maximal (Fm) and variab...

Abbreviations: a*PSII, optical cross section for photosys factor; Chl a, chlorophyll a; Ci, inorganic carbon; CO2, carb anhydrase; ETR, electron transport rate; FIRe, fluorescence Fm′ , light-adapted maximum fluorescence; Fv/Fm, maximum tochemistry in photosystem II; HCO3, bicarbonate; HEPE according to Lavergne and Trissl (1995); MIMS, membran enine dinucleotide phosphate; NaHCO3, sodium bicar...

The effects of increased photosynthetic active radiation (PAR), UV radiation (UVR), and nutrient supply on photosynthetic activity, pigment content, C:N ratio and biomass yield were studied in tank cultivated Gracilaria conferta (Rhodophyta). Electron transport rate (ETR) and biliprotein content were higher under high nutrient supply (HNS), obtained from fishpond effluents, compared to low nutr...

Electron transport rate (ETR) calculations require values of irradiance, effective quantum yield of chlorophyll fluorescence (DF=F0 m), the distribution of energy between PSII and PSI and leaf-specific photosynthetic absorptance. We conducted virtually simultaneous replicated measurements of diel changes in DF=F0 m of Posidonia australis in situ, and determined leaf-specific photosynthetic abso...

Aristotelia chilensis (Mol.) Stuntz is an evergreen species endemic to Chile. It grows in open areas or under tree canopy, and its leaves emerge early spring summer. The objective of this study was determine changes photosynthetic parameters, total phenol content (TPC), antioxidant activity, anatomy apical basal A. during the year. Photosynthesis performance determined by measuring electron tra...