Polyclonal selection for abiotic stress tolerance in Arinto: Implications in yield and quality of the must

Abstract

The valorisation of genetic variability through the identification suitable genotypes for traits such as yield and must quality is an effective strategy used for grapevine selection. Currently, climate change-driven heat waves and drought affect plant growth and wine quality, but little information is available on intravarietal variability regarding responses to stress. In the current work, the intravarietal genetic variability of the Portuguese variety Arinto was studied for yield, must quality, and tolerance to abiotic stress. An innovative approach using rapid, and nondestructive measurements of surface leaf temperature (SLT), Normalized Difference Vegetation Index (NDVI), Photochemical Reflectance Index (PRI), and chlorophyll content (SPAD), was used in an experimental population of 165 clones of Arinto installed according to a resolvable row-column design with 6 replicates. Also, yield and quality characteristics of the must were quantified. Linear mixed models were fitted to the data, and the empirical best linear unbiased predictors (EBLUPs) of genotypic effects for each trait were obtained as well as the coefficient of genotypic variation (CVG) and broad sense heritability. The results enabled the selection of a group of genotypes with increased tolerance to stress, which maintained the must quality of Arinto.