EFFECT OF POLYAMINES ON MORPHOGENESIS OF IN-VITRO POTATO PLANTS (SOLANUM-TUBEROSUM CV BINTJE)

The addition to the culture medium of exogenous polyamines (putrescine, spermidine or spermine) caused a stimulation of the growth of aerial parts of potato cuttings. However, if spermine stimulated the tuber development, spermidine inhibited it while putrescine had no effect. The utilisation of polyamine biosynthesis inhibitors: alpha-DL-difluromethylornithine and methylglyoxal bis (guanylhydrazone), that respectively produced global opposite effects to those of putrescine and spermidine, gives support to the idea that polyamines are involved in morphogenetic process and this is further substantiated by the fact that inhibitor effects are partially reversed by adding polyamines. alpha-DL-difluromethylarginine, that had no appreciable effect, confirms the major participation of the ornithine decarboxylase in putrescine biosynthesis.