Salt stress effect on epinasty in relation to ethylene production and water relations in tomato

A pool of genetic variability is a prerequisite for any practical approach to improving crop salt tolerance. The objective of this study was to determine how epinasty, a morphological response of tomato to salt stress, can be used as a measure of salt tolerance and how it is related to ethylene production and water relations in tomato. Three Lycopersicon esculentum cultivars (Edkawy, Ramy, and Vemar) and one Lycopersicon sheesmanii accession were subjected to four levels of salt stress at the roots (0, 50, 100, and 200 mM NaCl). Epinasty increased with increasing levels of salinity depending on genotype, leaf age and duration of the salt stress. Relative ethylene production by tomato petioles also increased with the intensity of salt stress, genotype and leaf age; salt tolerant varieties exhibited less epinasty and a lower relative ethylene production.