Induction of genetic variation for drought tolerance in two rice cultivars amber 33 and amber Baghdad

الملخص EN

Seeds of two rice cultivars Amber 33 and Amber Baghdad were presoaked in the chemical mutagen Sodium azide at the concentrations 0.0, 0.5, 1.0 or 2.0 mM for 2, 4 or 6 hrs.

The effect of Sodium Azid was examined on seed germination, shoot and root length and promising dose.

To increase the genetic variation for drought tolerance, seeds treated with the optimum dose that made 40% in growth reduction in seedling height.

Calli were induced from mature embryos on appropriate medium and then transferred to a medium containing 0.0, 0.5, 1.0, 1.5 or 2.0% of Polyethylene Glycol (PEG) (W/ V).

Differences were recorded between cultivars and treatments with respect to the studied traits.

Results showed that there were no significant differences between cultivars in respect to seeds germination shoot and root length while these parameters decreased with increasing mutagen concentration and soaking time.

Results also revealed that there were significant differences between cultivars in % of callus induction and callus fresh weight when callus cultures were transferred to different combinations of 2,4-D and Kin, while there were no significant differences in callus fresh and dry weights between cultivars with increasing concentrations of Sodium Azide and PEG.

Callus fresh weight decreased with increasing PEG level in the medium for seeds not exposed to Sodium Azide.