C(4) photosynthesis has evolved more than 60 times as a carbon-concentrating mechanism to augment the ancestral C(3) photosynthetic pathway. The rate and the efficiency of photosynthesis are greater in the C(4) than C(3) type under atmospheric CO(2) depletion, high light and temperature, suggesting these factors as important selective agents. This hypothesis is consistent with comparative analy...

(a) Photosynthesis with protoplasm isolated from Chara or Nitella as measured by C(14) fixation has been obtained at a rate 12 to 15 per cent of that of the whole cells. (b) Photosynthesis by cut cells of Chara or Nitella with the vacuolar sap removed was at a rate comparable to that of the whole cells. (c) Both the protoplasm and the cut cells reduced CO(2) in the light to sucrose and hexose p...

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);...

On the base of the physiological processes and according to the balance of the carbon, a simulation model for photosynthetic production and dry matter accumulation was established for the peanut. The photosynthesis rate of unit green leaf area was scribed by negative exponential function. By analyzing the characteristic of the shoots, the Gaussian integration method was used to calculate the ph...

Photosynthetic rate, ribulose 1,5-bisphosphate carboxylase activity, specific leaf weight, and leaf concentrations of carbohydrates, proteins, chlorophyll, and inorganic phosphate were determined periodically from midbloom until maturity in leaves of soybean plants (Glycine max L., var. Hodgson) from which reproductive and vegetative sinks had been removed 32 hours before measurement, or contin...

Since the discovery of the Hill reaction (9, 10, 11, 12), there has accumulated considerable evidence (5, 7, 10, 14, 15, 16, 17, 20) indicating that it is indeed a partial reaction of photosynthesis. And in particular there is evidence that the normally limiting dark reactions of photosynthesis and the Hill reaction are identical (5, 7). Numerous substances inhibitory to photosynthesis and the ...

Individual leaves of potato (Solanum tuberosum L. W729R), a C(3) plant, were subjected to various irradiances (400-700 nm), CO(2) levels, and temperatures in a controlled-environment chamber. As irradiance increased, stomatal and mesophyll resistance exerted a strong and some-what paralleled regulation of photosynthesis as both showed a similar decrease reaching a minimum at about 85 neinsteins...

Background: Due to the high content of nitrogen in the municipal wastewaters, this study evaluated the efficiency of Scenedesmus as an important microalgae in the removal of nitrate from wastewaters and its application as an appropriate culture medium. As algae have high resistance to temperature and pH changes, they can absorb low concentrations of nutrients and need simple low-cost technolog...

salinity affects the yield and quality of fruits crops as result of modifying water and nutrient uptake. in split root system, it should be possible to reduce the deleterious effect of salinity on the plant growth. therefore, an experiment was conducted on strawberry with different concentration of nacl (0, 30, 60 and 90 mm) in a completely randomized blocks design in studding hydroponic greenh...