Singular effect of soil and climate on grapevine development and berry traits in two Italian cultivars, 'Glera' and 'Corvina'

Grapevine (Vitis vinifera L.) represents a particularly interesting species in terms of phenotypic plasticity, considering that the terroir, meaning the contribution of geography, geology, and climate of a certain place, together with the agronomic practices utilized, may deeply influence the berry phenotype of a particular cultivar at the physiological, molecular, and biochemical level. This phenomenon can lead to the production of wines that, although produced from the same clonal cultivar, present totally different enological profiles, and represents an issue of increasing interest not only from a biological but also from an economic point of view. The present study is aimed at a deeper understanding of the determinism of phenotypic plasticity in grapevine, trying to deconstruct the concept of terroir into two of its principal components, the soil and climate factors, and to describe the singular effect that different chemical and microbiological soil profiles, on one hand, and different geoclimatic conditions, on the other, can produce in terms of berry plasticity at the molecular, biochemical, physiological, and enological level. Here, we present preliminary results comparing physiological and phenological data in both the vegetative and reproductive phases of two grapevine cultivars, ‘Corvina’ and ‘Glera’, grown in different soils located in the same geographical location and, conversely, in the same soil under different environmental conditions. Both soil and climate strongly drove differences in vine growth and berry traits in terms of phenological development, sugar accumulation, and berry morphology. Moreover, two parameters considered in this study, sugar content and berry morphology, showed different behavior depending on the terroir factor combination (cultivar-soil-climate), and this supports the importance of a delicate balance among terroir inputs for obtaining a final product with unique characteristics.