Effects of salinity on taste quality and biochemical traits of four tomato varieties (Solanum lycopersicum) grown under hydroponic conditions

Todays, contamination of agricultural soils by different ways of salinity is increasing as a result of human and environmental factors that would reduce yield and quality of agricultural crops. However, there are some plants that can tolerate some degrees of salinity. Tomato is one of the horticultural crops, moderately sensitive to salinity even that salinity can improve its quality. So, a study was conducted using four varieties of tomato under normal and salt stress (3, 6 and 9 dS m-1) hydroponic conditions to evaluate tomato quality. The results showed that increasing in salinity improves the quality and taste of tomato with a reduction in pericarp thickness, fresh weight and total protein. However, when the degree of salinity exceeds 6 dS m-1, a significant difference was observed in fruit yield which was variety dependent. Also, there is a significant difference between salt tolerance, performance, and taste of different varieties. Furthermore, it is found that the activity of guaiacol peroxidase and catalase enzymes increased as well as an increase in the level of salinity. Tomato cv. Super Chief with the highest number of fruits per plant, high level of proline as well as catalase activity, has the best performance against salinity levels of soil and was more resistant to salinity than other varieties. Also, tomato ‘Super Chief’ had the highest taste index with a slightly decline in the yield. Salt stress tomatoes have more carotenoid than controls but the level of 9 dS m-1 salinity was not tolerable by all varieties.