[Genetic instability in Portulaca grandiflora (Hook)].

Portulaca grandiflora, a member of the Centrospermae, produces the alkaloid-type betalain pigment in its petals and stems. Variegation patterns were observed on the corolla of some clones. The authors postulate that in Portulaca grandiflora a relation exist between unstable mutations and the presence of transposable elements in the genome. Experiments with unstable mutants of Portulaca grandiflora having variegated flowers were done. The unstable loci cmI and rmI, which are involved in betalain synthesis were genetically analysed.