Genotype Variations in Water Use Efficiency Correspond with Photosynthetic Traits in Tempranillo Grapevine Clones

Mediterranean viticulture is highly dependent on soil water availability. Moreover, global warming likely to increase average temperatures and the frequency of heat waves, thus leading greater scarcity. To cope with this situation, much research focused selection genotypes higher use efficiency (WUE). Several previous studies indicated that WUE varies between Tempranillo cultivar some showing interesting improvement in leaf WUE. Here, we assessed associations physiological parameters six selected clones. The plants were cultivated pots two conditions applied sequentially: a well-watered period followed by moderate stress recovery phase. Growth intrinsic monitored during both periods. Pressure–volume AN/Ci curves measured after re-watered. At end season, biomass accumulation total irrigation used calculate whole plant (WUEWP). revealed significant differences several photosynthetic parameters, including mesophyll conductance (gm), maximum velocity carboxylation (Vcmax) respiration (R). Clones RJ51 1048 exhibited high WUE, but presented distinct traits: had highest gm, while genotype 1048, lowest R. This study confirms traits generally explain intracultivar diversity observed studies.