Location: Horticultural Crops Research2011 Annual Report
1a. Objectives (from AD-416)
1. Investigate leaf anatomy and morphology of well-watered and water-stressed grapevines using light and electron microscopy. 2. Monitor berry ripening and fruit quality characteristics of well watered and water stressed grapevines.
1b. Approach (from AD-416)
Research will be conducted on two cultivars in a greenhouse and drought conditions will be simulated. Leaves will be tagged on the vines of both cultivars to determine leaf age. During the dry-down and re-watering cycles, the physiological, anatomical, and morphological characteristics will be measured in both cultivars to assess drought resistance. Prior to sampling tissues for all microscopy studies, photosynthesis, dark respiration, and stomatal conductance will be measured on leaves of well-watered and water-stressed grapevines. Fruit quality characteristics such as Brix, pH, titratable acidity, color etc., will be measured to examine ripening behavior and quality characteristics during dry-down and re-watering cycles. Documents Grant with Washington State University. Formerly 5358-21000-034-32G (12/2008).
3. Progress Report
We used potted grapevines to better understand features that allow some cultivars to better adapt to drought stress. To achieve this goal, the three cultivars, Zinfandel, Grenache and Cabernet Sauvignon were subjected to four water regimes (0%, 33%, 67% and 100% irrigation). Stomatal conductance, the amount of water vapor or CO2 that moves into and out of leaves, decreased with increasing water stress levels. In a similar pattern, leaf water potential was lowest at the highest water stress level. Generally, leaves under high levels of water stress had higher wax content and higher relative water content under well watered conditions. In future studies, physiological, anatomical, and morphological measurements of drought resistant cultivars will be taken with the goal of being able to predict the drought tolerance of grape cultivars. Methods of project monitoring included meetings, e-mail, and phone calls.