In Vitro Early Vegetative Growth of Tomato (Solanum lycopersicum L.) Cultivars Under Salt Stress

Tomato (Solanum lycopersicum L.) belongs to the Solanaceae family and is considered an important vegetable worldwide. Its production has been challenged due to soil salinization and water shortages. Local tomato cultivars could be better adapted to salt stress. Based on this hypothesis, the present study was carried out to determine the variation in fourteen different tomato cultivars for salt tolerance. Seed germination, mean germination time, shoot length, and root length were examined under salinity stress (1.5 g L^-1 NaCl). Plant growth and seed germination were severely affected by saline conditions. The results of this in vitro experiment showed that the seed germination of Yellow Milk was significantly increased (73.33%) however, Pink Jade and Red Jade cultivars were significantly decreased under the NaCl treatment. Similarly, among the fourteen tomato cultivars, the mean germination time of only Yellow Pearl and Black Current significantly increased. Moreover, the shoot length of eight tomato cultivars decreased compared with the control, while the highest shoot length (12.5 cm) was recorded in the case of Saint cultivar. The root length of Taiwan Red Saint, Purple Beauty, Yellow Milk, Red Pearl, Yellow Pearl, Pink Cooperative 906, Qinzu Shanghai 903, and Scarlet cultivars significantly increased, while the other five cultivars significantly decreased under NaCl treatment compared to control. It is concluded that NaCl stress significantly affects the vegetative growth of tomato cultivars under in vitro culture.