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 d evelopment, spermidine inhibited it while putrescine had no effect. Th e utilisation of polyamine biosynthesis inhibitors: alpha-DL-diflurome thylornithine and methylglyoxal bis (guanylhydrazone), that respective ly produced global opposite effects to those of putrescine and spermid ine, gives support to the idea that polyamines are involved in morphog enetic process and this is further substantiated by the fact that inhi bitor effects are partially reversed by adding polyamines. alpha-DL-di fluromethylarginine, that had no appreciable effect, confirms the majo r participation of the ornithine decarboxylase in putrescine biosynthe sis.