Paper-chromatographic Studies on Change in Gibberellins during Seed Development and Germination in Pharbitis Nil

Abstract

Changes in gibberellins occurring during seed development and germination of Pharbitis Nil were studied by means of paper-chromatography and rice seedling method. The amount of gibberellin reached its peak on the 13th day after anthesis and thereafter markedly decreased. The maximum amount of extracted gibberellin corresponded to 0.35μg. of gibberellin A₃ per seed. Gibberellin extracted from etiolated seedlings decreased gradually after germination in the dark. Three zones of gibberellin activity were found at Rf 0.0-0.2, Rf 0.3-0.5, and Rf 0.55-0.7 on the chromatograms developed with the mixture of iso-propanol/ammonia/ water (10:1:1). The activity of Rf 0.55-0.7 was attributed to the chemically known gibberellin A₁, A₂, A₃, or A₄. In initial stages of seed development the gibberellin activity appeared mainly at Rf 0.55-0.7, while in mature seeds and seedlings at smaller Rf values of 0.0-0.2 and 0.3-0.5.