Gibberellin-like substances in immature berries of seeded and gibberellin-induced seedless Delaware grapes

Abstract

The activity of fractionated gibberellin (GA)-like substances extracted from the seeds and pericarps of seeded and GA-induced seedless berries of Delaware grapes collected at 21 days after full bloom was determined, and the main active components in pericarp tissue were identified by means of selected bioassays and thin-layer chromatography.
In the seeds the highest activity was detected in the basic ethyl acetate fraction with the barley endosperm assay, whereas in the pericarps of seeded and seedless berries the basic and acidic ethyl acetate fractions, especially the acidic ethyl acetate fraction, were predominant in activity among the four fractions of basic ethyl acetate, neutral chloroform, acidic ethyl acetate, and acidic butanol. Moreover, the active components in basic ethyl acetate fractions from seed and pericarp were completely different in Rf on the paper chromato grams.
The higher level of total GA-like substances was found in pericarp of seedless than seeded berries.
The GA-like substances in acidic ethyl acetate fractions from pericarp of seeded and seedless berries exhibited strong activity in dwarf pea, dwarf rice, and barley endosperm assays, but not in a cucumber assay, and they were very similar to GA₃ in Rf on the thin-layer chromatograms. These substances therefore seem to be identical with GA₃.