Observations on the Occurrence of Highly-Numbered Vascular Bundles in Coleoptile of Rice Plant.

[摘要] The present report deals with the variability of coleoptile nervation in the kernels obtained under different environments. The author grew a strain of rice variety "Tokyo-Tozomochi (glutinous)" under several emvironmental conditions. Kernels obtained were germinated and the number of vascular bundles in their coleptiles were determined. The results and the conculusions are as follows: 1. The numbers of the bundle were smaller in the kernels obtained under nitrogen-deficit, probably being due to the diminution of cell activity to differentiate into vascular bundles. They were larger under phosphate-deficit and, probably, under potassium-dificit. 2. The number was smaller in the kernels obtained from the plants grown under short-day conditions, and was larger under long-day conditions. 3. Their number was larger in the kernels when the area of the leaf was reduced by cutting out a portion of it, after the heading period. 4. The number of the bundles increased when the soil was treated. with chemicals such as fratol (sodium-salt of monofluoracetic acid) and 2.4-D, accompanied by delay of heading. But there were no chemicals effecting decrease of the number of bundles. 5. From the above observations, the author considers the phenomena of increasing of coleoptile nervation as may be regarded as the sign of adaptation or compensation for the unfavorable internal conditions in the course of the embryo development.

[学科分类] 农业科学（综合）