Abstract
Following the experiment reported in the previous paper, experiments were carried out about the effect of concentration of gibberellin (GA) and kinetin on the growth of tiller buds as well as apical buds of rice seedlings on agar medium with or without auxin (IAA), kinetin or GA. The 5th node tiller buds and apical buds were taken out from the rice seedling grown with enough space (4.5 cm × 5 cm) at seedling age 6.5 and used in the experiments. The growth of tiller buds was promoted by existence of kinetin at the concentration around 10-7 mol, though it was inhibited at high concentration such as 10-4 mol. As to the effect of GA, the growth of tiller buds was promoted by some kinds of concentration of GA under thc existence of kinetin; however, the growth of apical buds was promoted by GA only under the condition with IAA and without kinetin. It was observed in tiller buds and in apical buds in common that the growth was very poor when none of IAA, GA and kinetin was supplied and that the growth was not promoted by GA and kinetin when the medium lacked both of the other two growth substances. The growth of apical buds was greater than that of tiller buds in general. The rooting of bud was generally observed to be promoted by IAA in tiller buds and apical buds. However, some difference was recognized between tiller buds and apical buds as to the effect of kinetin and GA on rooting.
