Studied on Branching Habits in Crop Plants : 3. Effects of leaf removal or addition of gibberellic acid throuth leaf blade on the growth of tillering buds in rice seedlings.

[摘要] On the existence of any connection between the leaf blade and the tillering bud, studies were made by means of removal of leaf blade of different leaves or absorption of gibberellic acid (GA) through different leaves. In 1958, the leaf blade of the 4th (plot A) or the 3rd (plot B) leaf or both of them (plot C) were removed at seedling age 4. In 1959, the 5th (plot A) or the 4th (plot B) or both of them (plot C) were removed at age 5. GA was absorbed through the 4th or the 5th leaf blade at seedling age 5, in 1959. After the treatment, dry weight of plant, both growth in length and differentiation of leaves of each tillering buds were traced. The removal of leaf blade retarded the growth of each tillering bud as well as accumulation of dry weight of plant (fig. 1-fig. 4, table 3). When removed at seedling age 4 (fig. 3), the removal of the 3rd leaf or the 4th leaf or both of them caused similarly the retardation of the 2nd, 3rd and 4th tillering buds especially the 3rd and 4th ones. In the case of removal at seedling age 5, the removal of the 4th, or the 5th or both of these leaves retarded similarly the 3rd, 4th and 5th tillering buds especially the 4th and 5th ones. Moreover, the retardation in the growth of these tillering buds were nearly proportional to the inhibition in accumulation of dry matter in whole plant (table 4). That is, which tillering bud is retarded is recognized to be not due to which leaf is removed, but due to when leaf is removed. The absorption of GA through the 4th or the 5th leaf blade inhibited the growth of tillering buds. Also in this case, difference in leaf treated did not cause the difference in the situation of tillering bud inhibited (table 6). From these results, the growth of tillering bud is recognized to be not related to some particular leaf of main stem but related to all of leaves. In addition, when treated at seedling age n the n-th and (n-1)th tillering buds were affected sensitively.

[学科分类] 农业科学（综合）