Studies on Internode Elongation in Soybean Plants : IV. Effects of gibberellin biosynthesis inhibitors on internode elongation

[摘要] In order to obtain the fundamental information on chemical control of plant structure in soybean ( Glycine max Merr. cv. Fukuyutaka), the effects of growth regulators on the internode elongation were examined. The chemicals used were the gibberellin biosynthesis inhibitors of AMO 16 18, Ancymidol, Uniconazole, Pa-clobutrazol and CCC. They were sprayed with different concentration solutions on the pot-grown plants at the different growth stages. When AMO 16 18 was sprayed at different growth stages, plant height was reduced by the application at the floral differentiation and the beginning of- flowering stages, and the former was found to be more effective (Table 1, Fig. 1 ) . Gibberellin biosynthesis inhibitor applications at floral differentiation stage inhibited the internode elongation, and Paclobutrazol and Uniconazole were most effective followed by AMO 1618and Ancymidol. However, the CCC hardly effected the vegetative growth (Table 2). When the Paclobutrazol, Uniconazole and AMO 1618 were applied, the inhibition of elongation was observed on the internodes that reached at mid-phase of elongation after treatment, whereas the inhibition was found to occur on the upper internodes when Ancymidol was used (Fig. 2) . On the other hand, the diameter of internodes was also reduced by the gibberellin biosynthesis inhibitor applications. These effects were observed on the internodes, which were lowered by 3 or 4 internodes from that reduced in length (Fig. 2). Though these growth regulators showed some disadvantages in plant growth, such as reduction of vegetative growth and pod elongation, it may become an useful tool to control internode elongation by the development of more useful chemicals applicable to soybean culture.

[学科分类] 农业科学（综合）

[关键词] Chemical control;化学的制御;Gibberellin biosynthesis inhibitor;ジベレリン生合成阻害剤;Growth regulator;植物生長調節物質;Growth retardant;伸長制御;Internode elongation;節間伸長;Soybean;ダイズ;Control of elongation;矮化剤