GENOTYPIC RESPONSES OF CULTURED TOMATO PLANTS TO SALT STRESS

Abstract

This study was carried on the plant tissue culture laboratrory of Department of Horticulture, Suez Canal University. In the current study, different physiological and biochemical salt responses were studied in callus AND regenerated tissues of three cultivated (Castlrock, Oriet and Super Marmande) and three imported breeding lines (BL-1076, BL-1077 and BL-1079) tomato ( Lycopersicon escu/entum) genotypes. Four major experiments were designed for: 1) selection of explant type for callus induction, and organogenesis, 2) determination of genotype capacity for callus growth, and regeneration in salt - free medium 3) determination of genotype capacity for callus growth and regeneration capacity on saline medium, and 4) analysis of callus and regenerated tissues of the six genotypes grown on salt-free and saline media for accumulated free proline, chlorophyll pigments, SDS-PAGE protein electrophoresis, and estimation of mineral composition. The obtained results of explant selection revealed that hypocotyl segments and true leaf were chosen as explants for callus induction and regeneration trials in vitro, respectively. The six investigated tomato genotypes differed among each other in their callus growth and regeneration capacities. Super Marmande (cultivated) and BL-1079 (salt­ tolerant inbred line) seemed to perform better for both callus growth and organogenesis in the specified tissue culture media than the other tested tomato genotypes.