Abstract
An experiment was carried out for the development of salinity tolerant somaclones. Three of cabbage cultivars (Gazelle, Rotanda F and Primero F) seeds were used as plant material. Hypocotyl segments of cabbage (Brassica oleracea var. capitata) were excised from 7 days old-seedlings cultured in MS medium with various concentrations of plant growth regulators naphthalene acetic acid (NAA); 2, 4-dichlorophenoxyacetic (2, 4-D); kinetin (Kin) and benzyladenine (BA) for callus induced. The best media for induction and growth of callus was containing 1 mg/l NAA and 1 mg/l Km for 24 days. Then the produced calli were put under salt stress from different concentrations of NaCl (0, 50 and 100 Millimolar). Response of three cultivars of cabbage to callus growth and in vitro salt tolerance was evaluated. Primero F1 and Gazelle showed good callus growth under higher salt rate stress condition compared to Rotanda F1. No obvious differences were observed between the three cultivars at lower salt stress rates. Inter-simple sequence repeat (ISSR) and sodium dodecyl sulphate-poly acrylamide gel electrophoresis (SDS-PAGE) were used to assess the somaclonal variation among the developing callus under salt stress. ISSR results revealed high level of polymorphism (82.35%) using 10 ISSR primers, but only five of them gave reproducible polymorphic DNA pattern. The total number of amplified DNA bands was 34 of which 28 were polymorphic. The electrophoretic pattern of developing calli protein gave different molecular weight bands, ranging from 26 to 120 KDa with the presence of unique bands.