On the Detection Method of Growth-inhibiting Substance

Abstract

1. Details of the detection method of growth-inhibiting substance obtainable by keeping the agar block in contact with the upper cut surface of the petiole segment, are described in this report. The Avena-technique is used.
2. As the number of petioles per agar block increases, the positive curvature of the Avena-coleoptile becomes larger.
3. The maximum curvature of the Avena-coleoptile is got by one hour contact of the petiole with the agar.
4. The longer the length of the petiole-segment is the larger the curvature of the Avena-coleoptile becomes.
5. The maximum positive curvature of Avena-coleoptile is got by three hours contact of the agar with the coleoptile.
6. In the case of the agar block rich in the inhibiting substance, it requires 2 1/2 hours to get the coleoptile curvature larger than what is caused by the blank agar; while, in the case of the agar block, containing small amount of the inhibiting substance, it takes 3 hours.