The Relationship of Grape Leaf Stomatal Conductance and Water Potential with Leaf Position Under Drought Conditions

【Objective】An experiment was conducted to study the regulations of the changes of stomatal conductance and water potential at different leaf positions under drought conditions.【Method】The stomatal conductance and water potential at different grape leaf positions were detected by 3005F01 Plant Water Status Console and SC-1 Leaf Porometer after drought treatments.【Result】Under well-watered condition,stomatal conductance had a positive linear correlation with the leaf position;However,a slight drought could reduce the stomatal conductance at upper leaf position significantly,with not much influence on lower leaf position.A contrast phenomenon was found under severe drought condition,the stomatal conductance declined with the increase in leaf position,while the water potential still had a positive correlation with leaf position.【Conclusion】No relationship between stomatal conductance and water potential under well-watered condition was found.The sensitivity to drought of leaves at different leaf positions had an obvious difference,which was closely related to the change of water potential and corresponding feedback regulation.