根菜類のすいり現象の生理学的研究(第4報)

抽苔とすの発現との関係について

抄録

It has been generally said that pithy tissue of the root crops occurs when the plants bolting, but as there are many doubtful points on this problems and in order to clarify the exact nature of correla-tion between both phenomena, the author conduct-ed the following experiments by using “Osaka-shijunichi” radish.
1. The correlation between the bolting which is induced by vernalization in fall and the occurrence of pithy tissue.
The seeds which were vernalized in 5, 7, 9, 11 and 13 days, under the temperaure of 3_??_5°C and the non-treated seeds were sown at the same time, and their individual growth was examined, The former treated over 9 days a run to seed, and with the increase of period of cold treatment they exhibited the rising rate of bolting, but it was hard to recognize the difference of occurrence of pithy tissue between the bolting and the non-bolting plants.
2. The seeds were sown in the fertilized and non-fertilized field plots on March 1, 15, and April 1, and their growth were examined.
Earlier the sowing time, higher the rate of bolting was observed, but there was no recognizable difference of degree of occurrence of pithy tissue between the bolting and the non-bolting plants in any plots. As a whole, pithy tissue was found remarkably in the fertilized field where the growth was vigorous and the corpulency of the roots was rapid, whereas in the non-fertilized plots where their growth was poor, the occurrence of pithy tissue was rare.
From the results of the above two experiments, it seems that the bolting itself is at least not the chief cause of pithy tissue, in the plants used, but it is chiefly due to the corpulency of vigorously growing roots, as stated in the author's previous report.