Utilization of Tomato Landraces to Improve Seedling Performance under Salt Stress

Salt stress is considered as one of the most frequent factors limiting plant growth and productivity of crops worldwide. The aim of the study was to evaluate physiological and biochemical responses of nine diverse tomato genotypes exposed to salt stress. In this regard, four-week-old seedlings of one modern variety, five landraces, the salt-sensitive accession of ‘Ailsa Craig’, the salt-tolerant wild accession of S. pimpinellifolium ‘LA1579’, as well as the vitamin C-rich S. pennellii introgression line ‘IL12-4’, were exposed to moderate salt stress (200 mM NaCl) for 10 days. At the end of the stress treatment, agronomical traits and stress indices were evaluated, while gas exchange-related parameters, root electrolyte leakage, malondialdehyde content and ascorbic acid were also determined. All parameters were significantly affected by salt stress, but to a different extent, verifying the diverse degree of tolerance within the selected genotypes, and further highlighting the different stress-induced mechanisms. The landrace originated from ‘Santorini’ island, as well as the modern variety, which originated from traditional cultivars, demonstrated a better performance and adaptivity under moderate salt stress, accompanied by reduced lipid peroxidation and enhanced ascorbic acid content, indicating that they could be potential promising genetic material for breeding programs or as grafting rootstocks/scions.