The effect of 3-indolylacetic acid on the accumulation of starch in the root tissue of Cichorium intybus L. cultured in vitro

The relation between IAA-induced formation of amyloplasts in callus cells of chicory root and the influence of IAA on sugar uptake from the medium was investigated. Experiments with ¹⁴C-sucrose showed that IAA increased the uptake of sucrose from the medium. The amyloplast-like structures were also observed in callus grown on medium without IAA, but containing high concentration of sucrose (9%). The possibility of IAA influence on the formation of amyloplasts by increasing the permeability of cells for sugar is discussed.

Catharanthus roseus (L.) G. Don - plant regeneration and alkaloids content

We describe here a regeneration of plantlets of <i>Catharanthus roseus</i> (L.) G. Don from shoot tips and axillary buds. Shoot tips were excised from 7-day-old seedlings and were incubated in solid Nitsch and Nitsch (NN) medium supplemented with kinetin, benzyladenine (BA), indole-3-butyric acid (IBA) and β-indolylacetic acid (IAA) in various combinations. After two months in culture, regenerated rooted plantlets were cut and transferred to a new medium; the explants contained shoot tips or axillary buds. Four passages were done. We obtained about 200 rooting plantlets from one seedling. Then the plantlets were transferred to the soil and they grew under a foil tent. After five months of vegetation they were collected, dried and weighed. Chemical investigations of leaves of these plants were done. The vindoline and catharanthine were dominant alkaloids in the juvenile stage of plants (before blooming). Total amount of alkaloids, equal 2.95%, was gravimetrically determined in leaves of plants, after 4th passage, regenerated <i>in vitro</i> on NN medium supplemented with kinetin and IBA.