Abstract:We report a successful and efficient plant regeneration system using mature embryo of barnyardgrass (Echinochloa crus). The effect of different sterilization procedures on explant culture and the effect of plant growth regulators on regeneration process and acclimatization of transplanting were assessed. It was found that EtOH+0.1%HgCl2 was optimal for explant sterilization. Essentially, dehulled and sterilized seeds were plated on callus induction and subculture medium composed of MS basal salts and DL vitamins plus 2.5 mg/L 2,4D, 300 mg/L glutamine, 〖JP1〗500 mg/L proline, 3% maltose, 0.8% (w/v) agar at pH 5.8. Differentiation was carried out on a differentiation medium MS with 50 mg/L〖JP+1〗 inositol plus 1.0 mg/L 6BA, 0.2 mg/L kinetin KT, 0.5 mg/L NAA, 0.25 mg/L IAA, 3% maltose, 0.8% (w/v) agar at pH 5.8. Plantlets ranging from 3 to 5 cm in length were transferred to the rooting media comprising 1/2MS basal salts. In vitro regenerated plantlets were washed to remove the traces of agar and then were transferred to pots containing nutritious soil and perlite (2〖DK1〗∶1, v/v), and the survival rate was over 90%. The protocol developed in this study will facilitate barnyardgrass generation and is useful for the production of herbicideresistant transgenic plants.