Levin, R., Osmotek Ltd., P.O.B. 550, Rehovot, Israel
Stav, R., Department of Ornamental Horticulture, ARO, Volcani Center, P.O.B. 6, Bet-Dagan 50250, Israel
Alper, Y., Department of Agriculture Engineering, ARO, Volcani Center, P.O.B. 6, Bet-Dagan 50250, Israel
Watad, A.A., Department of Ornamental Horticulture, ARO, Volcani Center, P.O.B. 6, Bet-Dagan 50250, Israel

Contaminated Syngonium clusters were multiplied in an air lift bioreactor in liquid medium containing sucrose with the medium being circulated through a sterilizing filter. After 30 days, the culture in filtered medium produced 19.5 shoot initials per gram fresh weight of inoculum compared to 8.7 shoot initials produced in unfiltered medium. Transfer to an elongation medium with 30 mg l-1 Rifampicin produced shoots on 67% of the clusters, while transfer to elongation medium without Rifampicin produced shoots on 40% of the clusters. Clusters grown for three subcultures in a reactor without medium filtration had lost their multiplication ability. Clusters grown for three subcultures in a reactor with filtration, however, continued to show a two-three fold increase in fresh weight and shoot production.