Relationship between 18O enrichment in leaf biomass and stomatal conductance.
Models that explain the oxygen isotope enrichment in leaf water (and biomass) treat the relationship between the kinetic fractionation that occurs during evapotranspiration and the stomatal conductance in an empirical way. Consequently, the isotopic enrichment is always predicted to decrease with increasing stomatal conductance, regardless of the experimental evidence to the contrary. We explain why and suggest an alternative method to reconcile theory and experiment. We support this with our experimental data on rice and groundnut plants.
Department of Crop Physiology, University of Agricultural Sciences, Bangalore, India. msheshshayee@hotmail.com
Madavalam Sreeman
MS
Sheshshayee
Hanumantha Rao
HR
Bindumadhava
Rengaswamy
R
Ramesh
Trichy Ganesh
TG
Prasad
Makarla
M
Udayakumar
D010367:Arachis / Q000235:genetics / Q000378:metabolism; D018533:Biomass; D007700:Kinetics; D008954:Models, Biological; D012275:Oryza / Q000235:genetics / Q000378:metabolism; D010100:Oxygen / Q000032:analysis / Q000378:metabolism*; D010103:Oxygen Isotopes; D018515:Plant Leaves / Q000378:metabolism*; D054046:Plant Stomata / Q000378:metabolism*; D018526:Plant Transpiration / Q000235:genetics / Q000502:physiology*
D010103:Oxygen Isotopes; D010100:Oxygen