CHANGES IN THE CONTENT OF GIBBERELLIN-LIKE SUBSTANCES IN RIPENING SEED AND POD OF LUPINUS LUTEUS

The amount of gibberellin-like substances in seed, pod, embryoand "endosperm" of Lupinus luteus in relation to their developmentwas studied by means of the rice seedling test. The amount of gibberellin-like substances per seed increasedremarkably at the first stage of development, when the growthof seed and pod was very slow, and attained its maximum at suchan early stage as the dry weight of seed reached a value ofonly 10 per cent and that of pod 28 per cent of their respectivemaximum levels. Changes in amount of gibberellin-like substancespresent in the pod were very closely related to the changesin growth of pod. Gibberellin-like substances equivalent to0.3 µg gibberellin A₃ per seed and 0.028 µg perpod were found at the 20th day after anthesis, and no activityin mature seed and 0.09 µg per pod at the 50th day. Noactivity was found in the embryo itself at all stages, indicatingthat the gibberellin-like substances in seed occur only in the"endosperm," i.e. in the tissues that will eventually form testain fully ripened stage. (Received December 18, 1962; )