Somatic embryogenesis and polyploidy in grapevine: morphological shoot and leaf traits variations

A large varietal collection including over 1700 varieties was maintained in Conegliano, ITA, since the 1950s. Phenological data on a subset of 400 grape varieties including wine grapes, table grapes, and raisins were acquired at bud break, flowering, veraison, and ripening since 1964. Despite the efforts in maintaining and acquiring data over such an extensive collection, the data set has varying degrees of missing cases depending on the variety and the year. This is ubiquitous in phenology datasets with significant size and length. In this work, we evaluated four state-of-the-art methods to estimate missing values in this phenological series: k-Nearest Neighbour (kNN), Multivariate Imputation by Chained Equations (mice), MissForest, and Bidirectional Recurrent Imputation for Time Series (BRITS). For each phenological stage, we evaluated the performance of the methods in two ways. 1) On the full dataset, we randomly hold-out 10% of the true values for use as a test set and repeated the process 1000 times (Monte Carlo cross-validation). 2) On a reduced and almost complete subset of varieties, we varied the percentage of missing values from 10% to 70% by random deletion. In all cases, we evaluated the performance on the original values using normalized root mean squared error. For the full dataset we also obtained performance statistics by variety and by year. MissForest provided average errors of 17% (3 days) at budbreak, 14% (4 days) at flowering, 14.5% (7 days) at veraison, and 17% (3 days) at maturity. We completed the imputations of the Conegliano dataset, one of the world’s most extensive and varied phenological time series and a steppingstone for future climate change studies in grapes. The dataset is now ready for further analysis, and a rigorous evaluation of imputation errors is included.

Nel 1990 la Cantina LA VIS ha intrapreso un progetto di zonazione dei terreni vitati allo scopo di acquisire le conoscenze scientifiche atte a consentire il miglioramento delle qualità dei prodotti. Tale progetto si è articolato su di una superficie di 2000 ettari ubicati lungo l’asta fluviale del fiume Adige da Trento a Salorno e del torrente Avisio da Lavis a Segonzano.

For wine areas around the world, nature and climate are becoming factors of production whose endowment becomes a stake beyond the traditional economic factors: labor, capital, land. They strongly influence agricultural and environmental conditions for production.

Grapevine susceptibility to fungal diseases, including the vascular disease esca, is a major threat for wine productivity and vineyard perennity worldwide.

Several factors like vineyard site, climate, grape variety, ripeness, physical health of the grapes and pest management influence the populations of indigenous yeasts on grapes and later on in spontaneous fermentations.