Comparing Selection Criteria to Select Grapevine Clones by Water Use Efficiency

The current climate change is forcing growth-adapted genotypes with a higher water use efficiency (WUE). However, the evaluation of WUE being made by different direct and indirect parameters such as instantaneous leaf (WUEi) isotopic discrimination carbon (δ13C) content fruits. In present work, has been evaluated in these two ways wide collection grapevine genotypes, including Tempranillo Garnacha clones, on rootstocks (T-rootstocks). A total 70 have analysed four experimental fields over years. used to measure were bunch biomass intrinsic (WUEi), defined ratio between net CO2 assimilation stomatal conductance. highest lowest identified, differences them found be more than 10%. Generally, showed coincidences clones WUE, suggesting that both are valuable tools classify their breeding programs. δ13C seemed better indicator for determining because it represents integration synthesis time sample (mainly sugars from ripening grapes), which coincides driest period crop. Moreover, WUEi variable parameter plant dependent environmental conditions. work suggests could an interesting clonal selection criteria grapevines WUE. main reasons its fact sampling less time-consuming easier do WUEi, samples can stored late determinations, increasing number analysed.