Studies on the Occurrence of Natural Gibberellin and Its Effects on the Tuber Formation of Potato Plants

[摘要] The present investigation was undertaken to ascertain whether the natural gibberellin is contained in the potato plant or not, and the effect of gibberellin on the tuber formation of potato plants was also studied, using two potato varieties of "Irish Cobbler" and "Norin No. 1" as materials in this experiment. The experimental results, obtained may by summarized as follows. According to the results of wheat leaf test, ultraviolet ray test and acid - and - alkaline treatment which were made using with the paper chromatogram obtained from ethanol extracts of potato tissues, it may be concluded .that there is some gibberellin like substances in the potato tissues. At least one of these substances may be regarded as the gibberellin itself, or seems to be highly similar to the gibberellin. On the relative amounts of natural gibberellin in the various parts of the potato plants, the following series was recognized in order; sprout > stem tip > tuber > middle part of stem > leaf. That some natural growth inhibitor is formed in the various parts of potato plants and it seems to act antagonistically to the gibberellin action, were also ascertained. On the other hand, it was noted that no tuber formation occurred when the gibberellin was applied to the potato plants, even under the short-day condition which usually caused a promotion of tuber formation. Judging from the facts described above, therefore, it seems reasonable to conclude that the natural gibberellin formed in the potato plants may play physiologically some important role in controlling the tuber formation of potato plants.

[学科分类] 农业科学（综合）