The influence of polyamines on androgenesis of Cucumis sativus L.

The influence of polyamines (putrescine and spermidine; 5-1000 muM) was studied on androgenesis of Cucumis sativus L. cvs 'Calypso' and 'Green Long'. Addition of polyamines (putrescine or spermidine; 5-200 muM) to the embryo induction medium [B5 (GAMBORG et al. 1968) containing 2.0 muM 2,4-dichlorophenoxyacetic acid (2,4-D), 1.0 muM 6-benzyladenine (BA) and 0.25 M sucrose] enhances the rate of embryogenesis and spermidine showed optimum response (90.66 and 100.33 embryos per 60 anthers of 'Calypso' and 'Green Long' respectively) at 200 muM. Higher concentrations (500 or 1000 muM) of putrescine and spermidine were not beneficial for embryogenesis. Embryo differentiation was achieved on B5 medium supplemented with 0.25 muM of alpha-naphthaleneacetic acid (NAA), 0.25 muM kinetin (Kn) and 0.09 M sucrose. Transfer of the differentiated embryos to maturation medium containing 0.09 M sucrose and 10 muM abscisic acid (ABA) resulted in maturation of embryos. Mature embryos developed into plantlets on germination medium containing 0.09 M sucrose. Embryos developed from anthers on induction medium containing 200 muM spermidine showed maximum regeneration efficiency.