Advanced lines of Pima cotton {Gossypium barbadense L.) bred for higher yield potential and heat resistance have higher stomatal conductance and smaller leaf areas than those of obsolete !ines. In controlled experiments, five commercial lines of Pima cotton having increasing lint yield and heat resistance showed a gradient of increasing stomatal conductance and decreasing leaf size. In field ex...

Plants exchange greenhouse gases carbon dioxide and water with the atmosphere through the processes of photosynthesis and transpiration, making them essential in climate regulation. Carbon dioxide and water exchange are typically coupled through the control of stomatal conductance, and the parameterization in many models often predict conductance based on photosynthesis values. Some environment...

The photocontrol of the functional coupling between photosynthesis and stomatal conductance in the leaf was investigated in gas exchange experiments using monochromatic light provided by lasers. Net photosynthesis and stomatal conductance were measured in attached leaves of Malva parviflora L. as a function of photon irradiance at 457.9 and 640.0 nanometers.Photosynthetic rates and quantum yiel...

Methyl jasmonate and Epi-brassinolide as plant growth regulators have significant biological effects on plant growth, including increased tolerance to salt stress in plants. In this study, the effects of salinity stress and its interaction with methyl jasmonate and Epi-brassinolide on chlorophyll concentration, rate of photosynthesis, transpiration, stomatal conductance and resistance and chlor...

BACKGROUND AND AIMS The influence of stomatal architecture on stomatal conductance and on the developing concentration gradient was explored quantitatively by comparing diffusion rates of water vapour and CO(2) occurring in a set of three-dimensional stoma models. The influence on diffusion of an internal cuticle, a sunken stoma, a partially closed stoma and of substomatal chambers of two diffe...

The internal conductance to CO2 supply from substomatal cavities to sites of carboxylation poses a large limitation to photosynthesis. It is known that internal conductance is decreased by soil water deficits, but it is not known if it is affected by atmospheric water deficits (i.e. leaf to air vapour pressure deficit, VPD). The aim of this paper was to examine the responses of internal conduct...

A new imaging system capable of simultaneously measuring stomatal conductance and fluorescence parameters, non-photochemical quenching (NPQ) and photochemical yield of photosystem II (Phi(PSII)), in intact leaves under aerobic conditions by both thermal imaging and chlorophyll fluorescence imaging was developed. Changes in distributions of stomatal conductance and fluorescence parameters across...

net photosynthesis rate (pn), stomatal conductance (gs) and transpiration rate (e) of anise hyssop were measured during the four cloudless days, in reference to diurnal fluctuations of leaf temperature (tleaf), leaf vapor pressure deficit (vpd leaf) and photosynthetic photon flux density (ppfd) in well watered (ww), stressed (s) and recovered (r) plants. an analysis of measured data showed that...

Sap flux density in branches, leaf transpiration, stomatal conductance and leaf water potentials were measured in 16-year-old Quercus suber L. trees growing in a plantation in southern Portugal to understand how evergreen Mediterranean trees regulate water loss during summer drought. Leaf specific hydraulic conductance and leaf gas exchange were monitored during the progressive summer drought t...

abstract study on photosynthetic and enzym activity changes in lettuce under cadmium stress has been done in greenhouse. of zhejang university in chine the experimental design was a crd factorial design organized in hydroponic system with 7 replications. cadmium was added to nutrient solution in cdcl2 in three concentrations (0, 2, 4 mg/l). stomatal photosynthetic factors (transpiration, stomat...