LIQUID-SYSTEM SCALE-UP OF CARICA-PAPAYA L. SOMATIC EMBRYOGENESIS

Carica papaya L. embryogenic calli cultured in a liquid phase maturati on medium resulted in a significantly higher frequency of somatic embr yogenesis (SE) and regeneration than parallel treatments on agar-solid ified medium. An average of 455 somatic embryos per hypocotyl explant were produced in a liquid system after 112 d as compared with 174 SE p er explant on solidified medium. Superior early-stage SE were produced in maturation medium with 6% sucrose, as compared with treatments wit h only 3% sucrose, as evidenced by a higher successful germination rat e of embryos into plantlets. Medium containing 0.5 mu M abscisic acid (ABA) in the maturation phase increased average embryo size from 1.5 m m to 2.5 mm. Somatic embryos developed into normal papaya plantlets.