Effect of EMS mutagen on induction of salinity resistance of in vitro Jojoba Simmondsia chinensis L.

The present study aimed to induce mutation in jojoba Simmondsia chinensis L. in order to increase salinity tolerance using the chemical mutagen ethyl methane sulfonate (EMS). Micro cuttings of jojoba (Simmondsia chinensis L.) were treated with EMS at 0.0, 1%, 2%, 3% and 4% concentrations. Afterwards, to evaluate the reaction of the resulting mutagenized tissues to salinity stress; Regenerated shoots were treated with sea salt concentrations at 0.0, 15%, 25%, 50% and 100.0% during two successive seasons of 2016 and 2018. Results showed that treated shoots from both 3% and 4% EMS concentrations had high survival percentage of (80.0% and 73.30% respectively) when treated with 25% of sea salt. Moreover, jojoba shoots treated with EMS concentrations 3% and 4% gave a high survival percentage when treated with sea salt concentration 50% (73.30 % and 66.6%, respectively). Shoot length and number of leaves were affected by salinity stress compare to control. But there was significant increase in number of shoots in all salinity treatments compare to control. Random amplified polymorphic DNA (RAPD) analysis was performed to determine whether EMS treatments could induce genetic variability. RAPD analysis had successfully generated identifiable polymorphic products. Five random 8-mer primers were used to amplify genomic DNA of two EMS treated jojoba plants samples that exhibited high salinity tolerance compared to control. Which produced 142 detectable bands, of which 50 (35.2%) was polymorphic. In conclusion, treatment with 3% and 4% EMS mutagen concentrations under 25% and 50% sea salt concentration gave high survival percentage in jojoba shoots.