Impact of high temperature stress on ascorbic acid concentration in tomato

Higher temperatures are among the most important factors associated with climate change that may affect productivity and quality of horticultural crops.
In particular, changes in air temperature may alter the vitamin C content of vegetables.
The present study examines the effect of an increased day temperature (from 24 to 32°C) on vitamin C concentration in tomato, when the increase is imposed at different fruit development stages: flowering (stage 1), fruit set (stage 2), fruit with diameter <40 mm (stage 3), fruit with diameter <50 mm (stage 4), fruit with diameter <60 mm (stage 5) and green fully developed fruits (stage 6). Fruit grown at 24°C throughout the development period was considered the control treatment.
Plants were grown in 15-L pots filled with a mix of coconut fibre and perlite (85:15) and irrigated with Hoagland nutrient solution.
Fruits treated at the different development stages were sampled at the full red ripe stage.
The effect of increased temperature depended closely on the stage in which the treatment had been applied.
The vitamin C concentration was significantly lower when a temperature of 32°C was imposed during the advanced stages of fruit development (stages 5 and 6) compared with the control treatment.
No effect was observed when the temperature was increased in stages 3 and 4. Finally, the vitamin C concentration was seen to increase when the temperature stress was imposed during stages 1 and 2, indicating the adaptation of the plant metabolism to high temperature.

VIII International Postharvest Symposium: Enhancing Supply Chain and Consumer Benefits – Ethical and Technological Issues

V. Hernández, P. Hellín, J. Fenoll, M.V. Molina, I. Garrido, P. Flores

vitamin C, agricultural factors, functional quality, adaptation, abiotic

https://doi.org/10.17660/ActaHortic.2018.1194.140