Redox priming alleviates dormancy and improves salinity tolerance of seeds and seedlings of medicinal halophyte Zygophyllum simplex L.

Information about efficacy of redox priming in improving germination and salinity tolerance of seeds and seedlings of halophytes is scant. This study examined the effects of various redox priming treatments on seed germination, seedling growth and salinity tolerance of Zygophyllum simplex L. Priming of seeds with redox compounds hydrogen peroxide (H₂O₂) (3.5 folds) and nitric oxide donor sodium nitroprusside (SNP) (4.5 folds) were found to be most effective in overcoming the primary dormancy, irrespective of priming duration and concentration·H₂O₂ priming treatment improved 6- and 5-fold, whereas SNP priming led to a 3–6-fold increase in germination and germination rate index in moderate and high salinity, respectively·H₂O₂ priming also improved germination recovery when un-germinated seeds were transferred from high salinity to water. These treatments also improved early seedling growth parameters including total length, leaf area and chlorophyll (a and b) content. Hydro-priming caused a marginal improvement in some germination and seedling growth attributes in comparison to redox priming treatments. Hence, priming of Z. simplex seeds with H₂O₂ and SNP can be helpful for mass scale cultivation of this medicinal halophyte on saline lands with salty water irrigation.