Effects of ozone on stomatal responses to environmental parameters (blue light, red light, CO_2 and vapour pressure deficit) in three Populus deltoides × Populus nigra genotypes

摘要

The effect of ozone (O_3) on stomatal regulation was studied in three Euramerican poplar genotypes {Populus deltoides × Populus nigra: Carpaccio, Cima and Robusta). The impact of O_3 on stomatal conductance responses to variations in blue light, red light, CO_2 concentration and vapour pressure deficit (VPD) was studied. Upon O_3 exposure, a sluggish response of stomatal movements was observed, characterized by slower reactions to increases in blue light intensity, CO_2 concentration and VPD, and lower amplitude of the response to variations in light intensity. That sluggish response should be taken into account in stomatal conductance models for phytotoxic ozone dose (POD_Y) calculations. The speed of the response to variations in environmental parameters appears as a determining factor of genotype-related sensitivity.