Abstract
The present investigation was undertaken to ascertain the variations of natural gibberellin contents in the potato plant cultivated under the different environmental conditions. Certain varitions of natural gibberellin contents in the leaf blades due to the different environmental conditions were ascertained, e. g., a considerable decrease in amount was resulted from the exposure to the necessary low temperature (13°C) under short-day conditions (8 hours day-length), both of which are most favorable factors for tuberization of potatoes. Similarly, decline of the gibberellin content in the tubers was also resulted, keeping pace with the senility of tubers which are stored for a long duration of time over their rest period. When senile tubers were exposed to diffused light in the green house for about one month. Such tubers recovred their sprouting activity. At the end of this treatment, the amounts of natural gibberellin contained in the treated tubers were found to have increased markedly. From these results, it seems reasonable to assume that the amount of gibberellin contained in potato plants may be one of the principal factors for the tuber formation.
