Selection of salt tolerant plants of Nicotiana tabacum L. through in vitro and its biochemical characterization

Sodium chloride tolerant organogenic callus lines of Nicotiana tabacum were developed in vitro on Murashige and Skoog [16] medium supplemented with BA, IAA and different concentration of NaCl. The maximum shoot bud regeneration was achieved from both tolerant and non-tolerant calluses on MS medium supplemented with 1.0 mg/1 BA, 0.1 mg/1 IAA with or without NaCl within 4 weeks of culture. Standard growth parameters such as fresh weight and dry weight of organogenic callus, growth tolerant index and enzyme activity ( peroxidase and catalase) were used as indicators of salt tolerance. The growth tolerance index in the 4-week after the beginning of treatments yielded significant differences among the non-tolerant and tolerant organogenic callus lines. The regenerated shoots were rooted on half-strength MS basal salts supplemented with 2% sucrose but devoid of growth regulator. The regenerated plants from tolerant callus lines were capable of growing in vitro in presence of 175 mM NaCl. SDS-PAGE profile showed that the progenies derived from tolerant sources were tolerant to salt. This investigation may help in the selection and characterization of salt tolerance in plant improvement programme.