precedingw or following irrigations. No reduction in the rate of photosynthesis was cletected as soil moisture was extracted, until the approximate time the first visible signs of wilting appeared. As the severity of wilting increased, the photosynthetic rate declined rapidly. When the plants were (listinctly wilted, photosynthetic activity had been reduced to approximately 75 % of its maximum ...

Measurements of gross photosynthesis; respiration, rate of net oxygen diffusion, and organic storage are reported for 7 microcosms maintained over periods of 5 to 7 months. Average rates of gross photosynthesis ranged from 0.86 to 1.69 g Oz/m2/day and were related to the amounts of inorganic nutrients added. Average final organic storage was equal to 35.6% of gross photosynthesis. Assumed photo...

the research aims at studying the effects of mycorrhizal fungi (glomus fasciculatum, g. mosseae and mixed composition) on growth, photosynthesis and nutrient absorption of ziziphus spina-christi in mehran greenhouse, ilam province. the result showed that colonization rate in mixed treatment was more than pure treatment of g. fasciculatum and g. mosseae. also, root fresh weight, stomatal conduct...

in order to evaluate the effects of atmospheric co2 concentration increment on rapeseed salinity tolerance, four levels of salinity(0, 5, 10 and 15 ds.m-1) on  three cultivars of rapeseed (okapi, zarfam, and rgs) at three levels of atmospheric co2 concentration(350, 700 and 1050 ppm) were studied. the experiment was conducted at the greenhouse of tarbiat modares university at 2010 and 2011 crop...

Effects of sulfur on photosynthesis in sugar beets (Beta vulgaris L. cv. F58-554H1) were studied by inducing sulfur deficiency and determining changes in the photosynthesis of whole attached leaves and of isolated chloroplasts. The rates of photosynthetic CO(2) uptake by intact leaves, photoreduction of ferricyanide, cyclic and noncyclic photophosphorylation of isolated chloroplasts, and the ra...

We present a simple method for describing the influence of variable attenuation of spectral irradiance, Kd(λ), on water-column photosynthesis and its inhibition by ultraviolet radiation (UV). The approach is based on weighted water transparency, a calculation introduced by Vincent et al. 1998 (Ann Glaciol 27:691–696). Key results of a depthand spectrally-resolved model of photosynthesis can be ...

The toxic equivalency concept is a widely applied method to express the toxicity of complex mixtures of compounds that act via receptor-mediated mechanisms such as induction of the arylhydrocarbon or estrogen receptors. Here we propose to extend this concept to baseline toxicity, using the bioluminescence inhibition test with Vibrio fischeri, and an integrative ecotoxicity endpoint, algal growt...

osmotic stress is one of the major factors that significantly reduce yields in dry areas. plants respond to this abiotic stress at physiological and molecular levels. many genes are induced under stress conditions by transcription factors. dehydration responsive element binding (dreb) protein is a subfamily of ap2/erf transcription factors which control expression of many osmotic stress-inducib...

We have extended a conventional photosynthesis model to simulate field and laboratory measurements of chlorophyll fluorescence at the leaf scale. The fluorescence paramaterization is based on a close nonlinear relationship between the relative light saturation of photosynthesis and nonradiative energy dissipation in plants of different species. This relationship diverged only among examined dat...