Development of NaCl-tolerant line in Tanacetum cinerariaefolium through shoot organogenesis of selected callus line

Plants were regenerated successfully through shoot organogenesis of a NaCl-selected callus line of Tanacetum cinerariaefolium (Trevir.) Schultz-Bip developed through stepwise increase in NaCl concentration in MS medium. Increasing NaCl level concentration (0, 5, 10, 15, 20, 25, 30, 35, 40, 45mM) from low level to high level was found to be a better way to isolate NaCl-tolerant callus line, since direct transfer of callus to high saline medium was detrimental to callus survival and growth. Among different media and growth regulator treatments, MS media containing 1 mgl-1 BA and 1mg l-1 NAA or 1 mgl-1 BA, 2 mgl-1 NAA and 0.5 mgl-1 GA3 for shoot organogenesis in selected callus line and B5 medium supplemented with 2 mgl-1 NAA showed best response for root regeneration. As increasing NaCl concentrations (From 0 to 45 mM) the ability of shoot and root regeneration were decreased. The selected callus line showed significance increase in proline content and decrease in pyretrine content. Based on growth performance and proline content (20 mM in callus line and 35 mM in shoot culture) could be considered as NaCl-tolerant line showing all positive adaptive features towards the salinity stress. Further studies about agronomic performance of obtained plants under saline soil condition are necessary for understanding to check the genetic stability of the induced salt-tolerance plants.