Studies on the Wilting Treatment of Corn Plants : II. The influence of wilting on the elongation of lower internodes and the behavior of rooting

[摘要] It has been known that the organs and tissues developed under wilting show the various morphological changes in the xerophyte plants and that the morphological changes due to dryness itself may not be able to increase the yield because all cells, tissues and organs diminish in size because of water deficit. The authors reported in previous paper that the fodder yield does not always decrease by the treatment of successive wilting. At the same time they observed such phenomena seemed to be the cause of the increased fodder yield by some morphological changes resulted from successive wilting at some stages of the developments. In the present paper the phenomena, i. e. the elongation of lower internodes and the appearance of the root developments by the wilting treatment are reported. 1. The elongation of lower internodes which developed during the wilting period from 6 or 9 leaves age to 12.5 leaves age, was retarded and the length of lower internodes became short. On the contrary the growth of upper internodes became supplementally vigorous. As the result of shorting of the lower internodes, the more nodes may be covered with soil easily by the work of hilling. 2. The brace roots from lower nodes begin to elongate from the lowest node at first and thereafter regularly from the upper ones. This pattern seems to indicate that there may be some relationship between rooting and internodal elongation. Under the unsuitable circumstances the brace roots stop to elongate about 3∼5 cm in length without branching and after then, even if the circumstances become better they do develop no longer, though the development of brace roots from the upper nodes is accelerated. 3. On corn plants experienced the successive wilting a number of roots become elongate after rewatering and as the results the number increase when wilting is not so hard, though they decrease when it is hard. The number of roots that begin to elongate during wilting period have the inclination to be reversed. 4. The influence of GA treatment on the growth of corn plants and the behavior of rooting was discussed from the hormonal stand point of view referring to the effects of gibberellin on them carried out by the writer and others.

[学科分类] 农业科学（综合）