Premium
Photosynthesis, Transpiration, Leaf Stomatal and Mesophyll Resistance Measurements by the Use of a Ventilated Diffusion Porometer
Author(s) -
BRAVDO BENAMI
Publication year - 1972
Publication title -
physiologia plantarum
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.351
H-Index - 146
eISSN - 1399-3054
pISSN - 0031-9317
DOI - 10.1111/j.1399-3054.1972.tb03602.x
Subject(s) - transpiration , photosynthesis , atmosphere (unit) , diffusion , compensation point , water vapor , vapor pressure , botany , materials science , horticulture , biology , chemistry , thermodynamics , physics , organic chemistry
A ventilated diffusion porometer was modified and adapted for simultaneous measurements of leaf resistance and photosynthesis (using 14 C). The system enables measurements to be made under field and laboratory conditions with different concentrations of CO 2 and vapor pressure gradients between the evaporating surfaces inside the leaf and the external atmosphere. The leaf is subjected to the porometer's atmosphere only for short periods (up to 30 seconds) and it is assumed that stomata are not affected. Establishing the linear regression of the effect of CO 2 concentration on net photosynthesis makes it possible to extrapolate for CO 2 compensation point, to calculate the overall resistance to CO 2 and the mesophyll resistance to CO 2 .