Impact of polyclonal selection for abiotic stress tolerance on the yield and must quality traits of grapevine varieties
The effects of climate change in viticulture are currently a major concern, with heat waves and drought affecting yield, wine quality, and in extreme cases, even plant survival. Ancient grapevine varieties have high intravarietal genetic variability that so far has been explored successfully to improve yield and must quality. Currently, there is little information available on intravarietal variability regarding responses to stress. In the current work, the intravarietal genetic variability of several Portuguese varieties was studied for yield, must quality, and tolerance to abiotic stress, through indirect, rapid, and nondestructive measurements carried out in the field.
The present work describes an innovative approach in selection for abiotic stress tolerance, performed in experimental populations of several varieties installed according to resolvable row-column designs with 4 to 6 replicates1. Representative samples of the intravarietal variability of three ancient varieties (Uva Cão, Castelão, and Moscatel Graúdo) under conditions of drought and extreme heat were measured for surface leaf temperature (SLT), a parameter that had already been used for the varieties Aragonez2 and Arinto3, with good results. This was complemented with analyses of yield and quality characteristics of the must. Linear mixed models were fitted to the data of the traits evaluated, 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 heritability4. The genotypes were then ranked according to their level of tolerance to abiotic stress, and the changes in yield and traits of quality of the must were assessed for those genotypes. The results obtained will be the basis to develop, for those varieties, a new type of polyclonal selected material with increased tolerance to abiotic stress, in relation to the average of the varieties.
Acknowledgements: Projects “Conservation and selection of ancient grapevine varieties” (PDR2020-784-042704), “Save the intra-varietal diversity of autochthonous grapevine varieties” (PRR-C05-i03-|-000016); FCT: DL57/2016/CP1382/CT0024 to LC; UIDB/04129/2020 and LEAF Thematic Line Project Clones4ClimateChange.
1) Gonçalves E. et. al. (2010) Experimental designs for evaluation of genetic variability and selection of ancient grapevine varieties: a simulation study. Heredity, 104: 552–562. DOI: 10.1038/hdy.2009.153
2) Carvalho L.C. et. al. (2020) Selecting Aragonez genotypes able to outplay climate change driven abiotic stress. Front. Plant Sci., 11: 599230, DOI: 10.3389/fpls.2020.599230
3) Carvalho L.C. et. al. (2023) Polyclonal selection for abiotic stress tolerance in Arinto: implications in yield and quality of the must. 44th World Congress of Vine and Wine, Cádiz, Spain, 5-9 June.
4) Gonçalves E. and Martins A. (2019). Genetic gains of selection in ancient grapevine cultivars. Acta Hortic., 1248, 47–54. DOI: 10.17660/ActaHortic.2019.1248.7
Issue: ICGWS 2023
1LEAF- Linking Landscape, Environment, Agriculture and Food, Associated Laboratory TERRA; Instituto Superior de Agronomia, Universidade de Lisboa, Portugal
2Associação Portuguesa para a Diversidade da Videira – PORVID, Lisboa, Portugal