Physiological and chemical performance of the Flame seedless grapevine cultivar in the presence of Paulsen 1103 as the interstock

ABSTRACT Interstock is commonly used in deciduous fruit trees as a sustainable strategy to reduce the vigor of the scion associated with the high quality of fruits. In this study, we tested the effect of Paulsen 1103 (Vitis berlandieri x Vitis rupestris) as interstock on the grafting success, growth, and the physiological and chemical parameters of Flame seedless (Vitis vinifera) grapevine grafted onto Freedom (Vitis champinii x 1613C) and Paulsen 1103 rootstocks. This study was conducted over two seasons (2019 and 2020). The results indicated that direct grafting on the Paulsen 1103 rootstock recorded the highest grafting success percentage. Moreover, the grafting success percentage increased significantly when Paulsen 1103 was used as interstock between Flame seedless and Freedom rootstock (FI/P/Fr) compared to the grafting success without Paulsen 1103 interstock (FI/Fr). Also, using Paulsen 1103 as interstock between Flame seedless scion and Freedom rootstock (FI/P/Fr) significantly reduced the morphological parameters (shoot length, leaf area and the dry weight of shoots and roots) and physiological parameters of leaf (relative water content, transpiration rate, and stomatal conductance) but significantly increased the leaf chemical content (peroxidase activity, total phenols, total proline, and total soluble sugar content) compared to values of the parameters measured in Flame seedless grafted onto Freedom rootstock (FI/Fr). Peroxidase activity could be used for predicting the degree of compatibility in grapevine grafts. This study suggested that the effect of Paulsen 1103 interstock on the vegetative growth of scion is correlated with its effect on chemical content and physiological responses of the scion.