Analysis of the 'Superior Seedless' Vines' Berries Shattering during their Shelf-Life after being Grafted onto Several Rootstocks

Grapevines, are widely cultivated and have a significant global economic impact. Berry breaking is a critical practice for grape growers as it directly impacts fruit quality, ensuring optimal flavor development and desirable characteristics in the final product. An experiment was conducted over the 2021 and 2022 seasons at a commercial farm with sandy soil, focusing on 12-year-old vines. The experiment involved grafting 'Freedom,' 'Ruggeri 140Ru,' 'Paulson 1103P,' and 'Superior Seedless' rootstocks, and evaluating the results. Harvest dates were determined by testing bundle samples using SSC (16%) and storing them at room temperature for four days. The Paulson 1103P rootstock showed a lower rate of berry breaking compared to other rootstocks. The activity of xylanase (XLN; EC:3.2.1.8), polygalacturonase (PG; EC:3.2.1.15), and cellulase (CEL; EC: 3.2.1.4), was also comparatively reduced. Throughout the four days, the Paulson 1103P rootstock demonstrated superior physical and chemical quality traits. The levels of cell wall hydrolysis enzymes, including PG, XLN, and CEL, were lower in vines grafted onto the Paulson 1103P rootstocks. The influence of the Paulson 1103P rootstock on physical and chemical quality traits persisted throughout the first four days of shelf life. The results suggest that 'Superior Seedless' vines grafted onto the Paulson 1103P rootstock exhibited a more pronounced decrease in berry breaking rate until the end of the four-day trial storage period under ambient air conditions.