Plant regeneration from protoplasts of calamondin (Citrus madurensis Lour.)

Diploid callus cells arose from the hypocotyl region of plantlets differentiated by anther culture of Calamondin (Citrus madurensis Lour.). The callus grew vigorously on Murashige and Tucker's medium containing 10 mg l⁻¹ benzyladenine, and differentiated embryoids on a medium with 5% lactose and no plant growth regulators. This embryogenic potential was transferred to protoplasts which regenerated plantlets.

Preculture of callus in liquid medium containing 5% lactose, for 4–7 days prior to protoplast isolation, effected a high yield of protoplasts. Plating efficiency was increased in a medium solidified with agarose and/or layered with liquid medium.