Pedoclimatic abiotic stress tolerance observed on twenty-eight Sardinian autochthonous grape accessions and their resilience to climate change

The climate change imposes rising physiological stress on grapevine. The difference on abiotic stress tolerance of 28 Sardinian autochthonous grape accessions (SAGAs) were studied, to search for resilience differences among them, during a three-year trial. Two-way factorial experimental design and analysis were implemented considering the SAGA and the phenological stage as variability factor, whereas random factors were the year and plant replicates. Net photosynthesis, stomatal conductance, transpiration rate and midday stem water potential (mSWP) were measured from fruit set until harvest. GLM-ANOVA and HSD Tukey test were performed to analyse data and discriminate averages. The mSWP measured on all SAGAs allowed for distinguishing significantly the cultivars according to four water stress thresholds. No mSWP and leaf gas exchange difference were observed among groups when SAGAs were classified according to berry colour (white vs red). To better understand the stress tolerance differences among SAGAs, they were classified according to a resilience index, mSWP based. SAGAs were separated in a declining order according to a climate resilience index (CRI). The trial permitted to classify SAGAs on the base of the stress level induced by pedoclimatic environment, and to distinguish some autochthonous rarer accessions potentially much climate-resilient such as Tintillu, Moscatello, Remungiau di Serri and Muristellu, than others most diffuse accessions or cultivars such as Cagnulari and Vermentino.