in order to study of the effect of priming and salinity on physiological and chemical characteristics of wheat(triticum aestivum l.), an experiment was carried out at the experimental farm of shiraz university. results showedthat primed plants significantly reduced its gas exchanges by accelerating senescence under a series of salt stress,which became more serious along with the increasing of s...

Rates of photosynthesis, sucrose synthesis, starch accumulation and degradation were measured in sugar beet (Beta vulgaris L.) and bean (Phaseolus vulgaris L.) plants under a square-wave light regime and under a sinusoidal regime that simulated the natural daylight period. Photosynthesis rate increased in a measured manner in direct proportion to the increasing light level. In contrast to this ...

Photosynthesis is a process that indicates the productivity of crops. The estimation this variable can be achieved through methods based on mathematical models. Mathematical models are usually classified as empirical, mechanistic, and hybrid. To mathematically model photosynthesis, it essential to know: input/output variables their units; modeling used its classification (empirical, or hybrid);...

Coupled land surface and terrestrial ecosystem models are used to simulate energy and carbon fluxes over winter wheat at the Ponca City, Oklahoma, Ameriflux site. The terrestrial ecosystem model consists of photosynthesis and respiration (autotrophic and heterotrophic) sub-modules, which uses canopy temperature, soil moisture, and soil temperature simulated by the land surface scheme. The photo...

The effects of various calcium ion antagonists and ion transport inhibitors on photosynthetic O(2) evolution of corals, isolated zooxanthellae, sea anemone tentacles, and Chlorococcum oleofaciens were measured. Only the phenothiazine drugs were effective at inhibiting photosynthesis. Trifluoperazine, a calcium ion antagonist drug, inhibited at low concentrations, with 10(-4) molar and 8 x 10(-6...

Chlorella pyrenoidosa were allowed to photosynthesize for short periods of time in the presence of (14)CO(2) and HTO. Analysis of tritium and (14)C labeling of photosynthetic intermediate compounds showed that the T/(14)C ratio of glycolic acid was comparable to that of intermediate compounds of the photosynthetic carbon reduction cycle when photosynthesis was performed in nearly 100% oxygen an...

Despite of the downward acclimation of photosynthesis in C. convoluta, increased net photosynthesis and carbon balance can be anticipated in response to elevated atmospheric C 0 2 level. C 0 2 exchange measurement seems to be more indicative when detecting heavy metal stress than fluorescence parameters. Among these, the relative fluorescence decrease ratio (RFd690) shows damage first, suggesti...