Stomatal response and photosynthetic capacity of maize leaves at low temperature. A study on varietal differences in chilling sensitivity

The impairment of the turgor operated modulation of stomatal movement and changes in photosynthetic capacity were studied using two maize ( Zea mays L.) varieties of different chilling sensitivity. In the tolerant variety stomatal opening exhibited characteristic transients, while in the more susceptible strain chilling induced a monotonous increase of stomatal apertures. Photosynthetic capacity of the leaves (expressed in terms of ¹⁴CO₂ incorporation at 25°C) declined as a result of chilling regardless of stomatal opening. Nevertheless, tolerance was reflected in the preservation of a higher level of CO₂ fixation capacity and in a more successful recovery.