Effect of salt stress on plant regeneration of tomato (Lycopersicon esculentum Mill.)

The effects of plant growth regulators and type of explants on plant regeneration of two tomato (Lycopersicon esculentum Mill.) cultivars (Isfahani and Shirazi) under salt stress and without salt stress were studied. Different explants (leaf, stem, hypocotyl and cotyledon) were cultured on media with different hormonal combinations and different concentrations of NaCl (0, 40, 80, 120, 160 mM). After 40-45 days, callus production and plant regeneration was evaluated. NAA (0.4 mg/L) and IBA(0.2 mg/L) in combination with BAP (2 mg/L) were the best auxins for callus production in cultivars Isfahani and Shirazy respectively. Among 4 explants for callus production, stem was the best explant in two cultivars. Medium with IBA and BAP was the best for plant regeneration from different explants in two cvs too. The potential for of the plant regeneration was as leaf > stem > hypocotyl > cotyledon respectively in cultivars. Isfahani and leaf > stem > cotyledon > hypocotyl in cultivar. Shirazy. With increasing of NaCl callus production decreased and two cultivars showed different plant regeneration ability in NaCl using stem and leaf explants. No somaclonal variation was observed accoding to assessment of morphology and RAPD-PCR analysis on regenerated plants. The difference between cultivars showed on callus production and plant regeneration originated form various genotypes.