A protocol has been developed for somatic embryogenesis and plant regeneration of sisal (
Agave sisalana Perr. ex. Engelm). Embryogenic callus cultures were initiated from young shoots raised in vitro from the stem portion of the bulbil on medium supplemented with 1–2 mg l
-1 kinetin (KN) and 0.2–0.5 mg l
-1 
-naphthaleneacetic acid plus KN or 1–1.5 mg l
-1 benzylaminopurine (BAP) or 0.25–0.5 mg l
-1 2,4-dichlorophenoxyacetic acid plus BAP or 0.5–1.0 mg l
-1 KN. Embryos at various developmental stages (globular-, heart- or torpedo-shaped) produced mature and germinating embryos on being transferred to a new medium containing 0–0.25 mg l
-1 KN. After 28 days, a maximum of 76% germinated embryos was obtained on a medium supplemented with 0.1 mg l
-1 KN. The capacity for embryogenesis remained constant in the callus upon subculturing on the same medium for more than 48 months. Histological observations showed a distinct multicellular origin for most of the somatic embryos as they developed from epidermal, sub-epidermal and inside callus cells, while a few of them originated from a superficial callus cell. Plantlets regenerated from embryos were transferred to the field where their survival rate was 100%.
Keywords Agave sisalana Perr. ex. Engelm - Callus culture - Somatic embryogenesis - Regeneration - Histological analysis
Communicated by W. Barz