The responsiveness to ethylene of net photosynthesis and stomatal conductance to water vapor in intact plants was investigated in 13 herbaceous species representing seven plant families. Exposures were conducted in an open, whole-plant exposure system providing controlled levels of irradiance, air temperature, CO(2), relative humidity, and ethylene concentration. Net photosynthesis and stomatal...

Water stress is one of the major abiotic stresses in agriculture worldwide. In order to assess photosynthesis response and grain yield of 25 wheat genotypes under water deficit (post-anthesis stress) conditions, a 2-year study (2010-12) was carried out as a split-plot arrangement using randomized complete block design with three replications. The most sensitive gas exchange variable to water de...

Interest in the thermal acclimation of photosynthesis has been stimulated by the increasing relevance of climate change. However, little is known about intra-specific variations in thermal acclimation and its potential for breeding. In this article, we examined the difference in thermal acclimation between alfalfa (Medicago sativa) cultivars originating from contrasting origins, and sought to a...

in order to prevent of inflorescence bud abscission and reduce of alternate bearing in pistachio cv. ‘ohadi’ an experiment with 12 treatments including of girdling, fruit thinning, application of urea (0.5%), sucrose (3 and 5%) and their combination with urea, zinc sulfate (0.05 and 0.1% of pure zinc) and also their combination with urea in 3 replication and during 2 stages, was conducted in 20...

The sugars of avocado leaves and leaf disks were labeled by photosynthesis in CO2 during various periods. The label found in the sugars was examined immediately following photosynthesis as well as after a period of respiration under various conditions. Sucrose was found to be the sugar most rapidly labeled during photosynthesis. Mannoheptulose was formed concurrently with sucrose but at a lower...

Photosynthesis produces chemical energy from photon energy in the photosynthetic electron transport and assimilates CO2 using the chemical energy. Thus, CO2 limitation causes an accumulation of excess energy, resulting in reactive oxygen species (ROS) which can cause oxidative damage to cells. O2 can be used as an alternative energy sink when oxygenic phototrophs are exposed to high light. Here...

intra-specific variation in responses of diurnal and long-term photosynthesis, stomatal conductance, chlorophyll fluorescence, and respiration in spring wheat (triticum aestivum l.) to salinity was investigated using two tolerant cultivars (cr and kharchia-65) and a sensitive one (ghods). plants were grown in sand culture in controlled environment at selected levels of salinity (5 as control, 1...

The responses of steady state CO(2) assimilation rate (A), transpiration rate (E), and stomatal conductance (g(s)) to changes in leaf-to-air vapor pressure difference (DeltaW) were examined on different dates in shoots from Abies alba trees growing outside. In Ecouves, a provenance representative of wet oceanic conditions in Northern France, both A and g(s) decreased when DeltaW was increased f...

Photosynthesis is a rather complicated process (Figure 1). Along the pathway, there are a series of energy transformations, redox reactions, and entry and exit points, any of which could influence the rate of the overall process. However, physiological measurements yield surprisingly simple relationships among a few environmental factors such as light and CO2 availability and overall rates of p...