Reviving Grapevine Massal Selection in the Context of Climate Change – A Strategy for Resilient Vineyards in the 21st Century

For centuries, grapevine improvement relied primarily on massal selection, a practice whereby growers identified and vegetatively propagated individuals with targeted phenotypic characteristics within vineyard populations of a given variety. Through repeated cycles of observation and multiplication, this empirical process generated populations according to production objectives that formed the foundation of early directed selection for wine production. In the 20th century, clonal and sanitary selection emerged as a decisive advance, delivering uniformity, health status, in particular with regard to virus diseases, and greater consistency in propagation material. Nevertheless, the widespread adoption of a narrow set of certified clones has led to significant genetic erosion, reducing the capacity of vineyards to buffer environmental fluctuations, adapt to climate change and resist to existing or emerging diseases and pests. Despite this evidence, a persistent perception persists that massal selections may offer complementary advantages over clonal material. This review synthesizes the historical trajectory of grapevine domestication and the emergence of modern varieties, the mechanisms underlying intra-varietal variation, including somatic mutations, epigenetic modifications and virome composition, and the consequences of clonal standardization on genetic diversity. Drawing on palaeogenomic, phenotypic and molecular evidence, it suggests that massal populations can serve as dynamic genetic reservoirs, preserving rare alleles, structural variants and adaptive trait combinations that are may be lost in clonal systems. Recent studies reveal that even within certified clonal collections, substantial exploitable variation persists, with moderate to high heritability and strong genotype-by-environment interactions enabling resilience under present and projected conditions. The strategic revalorization of massal selection, supported by high-throughput genotyping, metagenomics and precision tools, emerges as a powerful strategy to enhance viticultural competitiveness. By maintaining diverse populations that distribute risk across genotypes, epigenotypes and viromes, massal approaches may contribute to more stable yields, improved stress tolerance and sustained terroir expression without altering varietal identity. This review argues that the strategic co-existence of clonal and massal selection represents the ultimate expression of precision viticulture, allowing diverse populations to be matched to specific terroirs for enhanced long-term adaptability in a changing climate.