Water-use efficiency in grapevine cultivars grown under controlled conditions: effects of water stress at the leaf and whole-plant level

摘要

Background and Aims: Improving water-use efficiency (WUE) is desirable for future grapevine growth and grape production, especially in Mediterranean areas where water is predicted to be limiting. Understanding the genetic variability in WUE is important to identify the most appropriate cultivars to be used in semi-arid areas. Most previous studies have focused at leaf-level WUE, while information on whole-plant level is scarce. This study explored the genetic variability of grapevine in whole-plant WUE (WUE_(Wp)) to determine whether several leaf WUE (WUE_1) indicators are suitable as proxies of WUE~(wp). Methods and Results: Three similar experiments were performed to compare WUE in up to eight different grapevine cultivars under irrigation and water-stress treatments. Although WUE_1 and WUE~(wp) varied with cultivar and treatment, WUE_1 was not a reliable parameter to predict WUE~(wp). Conclusions: Large variability in WUE~(wp) between grapevine cultivars was observed, although this variability was not described by leaf-level indicators of WUE. Significance of the Study: This study showed that the large variability existing for WUE~(wp) in different cultivars offers an potential method for selecting the more suitable cultivars to grow in water-scarce viticulture areas, although WUE_1 is not reliable for estimating WUE~(wp).