The response of grafted bell pepper plants (Capsicum annuum L. var. grossum (L.) Sendtn.) to salt stress was investigated in this study by analyzing the photosynthetic traits and mineral content of the plants and the metabolic composition of the fruit. The bell pepper variety 'Vedrana' was grown ungrafted and grafted onto the salt-tolerant rootstock 'Rocal F1' , at two salinities (20 mM and 40 mM NaCl) and control (0 mM NaCl) during the spring–summer period. On a physiological level, similar stomatal restriction of photosynthesis in grafted and ungrafted plants indicated that grafting did not alleviate water balance disturbances under increased salt exposure. Measurements of midday water potential did not show improved water status of grafted plants. Thus, this grafting did not reduce the risk of ionic and osmotic imbalance in pepper plants grown under moderate salt treatment. Changes in the biochemical profiles of the pepper fruit were seen for both added-salt treatments. Salinity stress had a significant effect on fruit quantity, as reflected by a lower number of fruits and, in particular, a greater proportion of unmarketable fruits. This was most likely due to an interruption in Ca2+ supply due to high temperatures during the summer in the greenhouse. The total weight of fruits per plant decreased due to salinity, and in addition, the fruits were smaller. However, they had higher soluble solids, sugar, ascorbic and malic acid content. Grafting did not contribute to reduce crop losses. Biochemical analyzes of the fruit also showed no significant differences between fruit from grafted and ungrafted plants.
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