Ozone damage to tobacco leaves related to stomatal conductivity through the lower surface
The ozone damage or fleck susceptibility of tobacco leaves was compared with their stomatal conductivity. Replicated field plots of the following varieties of tobacco were studied: Conn. 49, which is fleck-susceptible; var. 6542, genetically similar to Conn. 49 but fleck-resistant; Bel W-3, which is very susceptible to fleck; and var. 6589, a fleck-resistant selection from Bel W-3. A portable diffusion porometer that exerts no pressure or vacuum was used on attached leaves to determine the separate rates of water loss from both the upper and lower surfaces. This rate is a measure of the stomatal conductivity. The measurements were taken on a sunny day when the ozone concentration was high. Silicone rubber impressions of the leaf surfaces were also made for stomatal counts. The stomata in all the varieties remained open during the period of observation. Neither the number of stomata/cm/sup 2/ of either surface nor the conductivity of the upper surface was related to the measured fleck rating. However, fleck damage was significantly correlated with stomatal conductivity of the lower surface. The faster the exchange of air and water vapor through the lower surface of the tobacco leaf, the greater the fleck damage.
- Research Organization:
- Connecticut Agricultural Experimental Station, New Haven
- OSTI ID:
- 6296375
- Journal Information:
- Phytopathology; (United States), Vol. 58
- Country of Publication:
- United States
- Language:
- English
Similar Records
Oxidant injury to shade tobacco cultivars developed in Connecticut for weather fleck resistance
Ozone injury on Bel W-3 tobacco controlled by at least two genes