Stomatal responses of strawberry leaves to moderate ozone.

摘要

Strawberry plants (cultivars Elsanta and Korona) were fumigated for 8 h, 5 days a week with 75 ppb ozone for 8 days at an atmospheric CO2 concentration of 360 or 720 ppm, or were fumigated with 65 ppb ozone for 3 months at 360 ppm CO2. Short term ozone application at 360 ppm CO2 did not affect leaf gas exchange, but at 720 ppm, stomatal conductance was significantly reduced by ozone in both cultivars. Long term exposure to ozone increased stomatal density, stomatal conductance and intercellular CO2concentration in Elsanta leaves, which emerged under the ozone exposure. In Korona, long term ozone exposure did not affect stomatal density or leaf gas exchange. It was suggested that ozone can directly affect stomatal aperture in strawberry. The stomatal responses of Elsanta and Korona to ozone may be regarded as adaptations to maintain leaf net photosynthesis rates similar to those of untreated control leaves.