Morphological and anatomical responses of two Palestinian tomato (Solanum lycopersicon L.) cultivars to salinity during seed germination and early growth stages

Abstract

The effect of salinity (50, 100 and 150 mM NaCl) on seed germination and early growth of two Palestinian tomato (Solanum lycopersicon) cultivars (J1 and Ram) was investigated. Salinity delayed seed germination of both cultivars, and none of them reached 50% germination at 150 mM NaCl even after 21 days of incubation. The seedling height increased with time but decreased with increasing salinity level in both cultivars. Ram cultivar showed higher relative seedling height and higher relative root length than the J1 cultivar. The development of root system and leaves was reduced as salinity increased. Salt stress caused reduction in the vascular system in both root and stem. Meanwhile, salinity stress resulted in an increase in the thickness of the cortex region of the stem and a reduction in that of the root. The reduced severity of morphological and anatomical deformations observed in the Ram line is more tolerant to salinity stress than the J1 cultivar, during the early growth stage.