Stress Relieving Enzymatic Activities and Biochemical Changes during Bud Break in Manjari Kishmish (Vitis vinifera L.) Grafted on Different Rootstocks

Abstract

The study on changes in biochemical constituents and enzymatic activities in Manjari Kishmish during the bud break stage following fruit pruning was conducted at National Research Centre for Grapes, Pune. Manjari Kishmish grafted on Dogridge, 110R, 140Ru and 1103P rootstocks was selected for the study during 2024-25. Bud samples were collected at five different stages after pruning and analysed for enzymatic activities (catalase, peroxidase, and polyphenol oxidase) and biochemical constituents (carbohydrates, proline, protein, reducing sugar and phenols). Results indicated significant variation among different rootstocks. The rootstock 110R exhibited highest catalase, polyphenol oxidase and carbohydrate levels in the early stages, suggesting its role in promoting earlier bud break and sprouting. In contrast, 140Ru recorded the highest levels of proline, protein and phenols, which may contribute to delayed bud break but enhanced defense mechanisms. The rootstock 1103P showed maximum reducing sugar content. The study highlights the differential biochemical and enzymatic responses among the rootstocks and their influence on bud development and stress adaptation in grapevines.