Endogenous Plant Growth Substances in Developing Fruit of Prunus cerasus L. I. Levels of Extractable Gibberellin-Like Substances in the Seed1

Levels of gibberellin (GA)-like substances were determined in sour cherry ( Prunus cerasus L.) seed in relation to fruit development using the cucumber and dwarf pea bioassays. Two GA-like substances were found; one was soluble in ethyl acetate and the other, a more polar substance, in butanol. Concentrations of both substances increased to a maximum 14 days after anthesis and then decreased and remained low during Stage III. Changes in seed GA-like substances coincided with development of the seed components, nucellus, endosperm, and embryo, and the early enlargement of the pericarp, but not with subsequent development of the pericarp. Both the ethyl acetate- and butanol-soluble GA-like seed substances chromatographed at a lower Rf than GA 3 . The butanol-soluble component is probably not a glycoside, since no ethyl acetate-soluble GA was released on hydrolysis. The butanol-soluble component resembles GA 32 in polarity, partitioning characteristics and Rf.