Physico-chemical and postharvest quality characteristics of intra and interspecific grafted tomato fruits

The objective of this study was to evaluate the physico-chemical and postharvest quality characteristics of intra- and interspecific grafted tomato fruit. Anna F1, a commercial tomato variety was interspecifically (Tomato Scion and African eggplant rootstock (Solanum aethiopicum)) and intraspecifically (Tomato Scion and bacterial wilt resistant hybrid tomato rootstock) grafted. The tomatoes were grown in a greenhouse and harvested at mature green, turning and ripe stages respectively. The tomatoes were analyzed for size, weight, cumulative weight loss, color changes, texture, respiration and ethylene gas production rates, vitamin C and lycopene content. Interspecific grafting on Manyire green, AB2, and intraspecific grafting on Armada, and B.B rootstocks significantly improved physical and physiological attributes of the tomato fruit. There was significant difference (p < 0.05) in size and weight of grafted tomatoes and control at all the three maturity stages. Intraspecific grafted tomato fruits on Armada rootstocks had the best quality characteristics in terms of firmness, low weight loss, respiration and ethylene production rates which are associated with extended postharvest shelf-life. Intraspecific grafting reduced respiration and ethylene gas production rates with tomatoes grafted onto Armada rootstocks attaining the least climacteric peaks of 20.20 ml CO₂ Kg^-1h^-1 and 0.34 μL C₂H₄ Kg^-1h^-1 respectively at mature green stage, thus leading to extendend postharvest life of these tomatoes. Tomatoes grafted onto B.B rootstock had the highest vitamin C content (28.11 mg/100 g). In general, intraspecific grafting recorded the best quality traits over the interspecific grafting. However interspecific grafting of tomato onto African eggplant Manyire and AB2 rootstocks had lower but comparable fruit quality to intraspecific grafting.