Abstract
In the present study, there are used two kinds of varieties of tetraploid plants of radish (Raphaleus satigus L.), a variety of tetraploid ones of chinese cabbage (Brassica pehilae7esis Rupr.) and their diploid plants, the polyploids being believed to have been derived from the diploids by the colchi ?? ine treatment. The leaves (the 6-8 th ones fro, m the growth 'point) of the plants grown on the iield were taken into the' Iaboratory, where they were put in pure water 'for a day and then in 0.1 KelO solution for a few days, resulting in that the tetraploid plants, are found much waker to the toxicant than the diploid ones. According to the hypotheses proposed by YA, MASAKI, one of the authors, pertain-ing to the :'physiology = of the toxicant resistance, the above noted facts seem to be due. 'co th.e dif-ference between' the tetraploid and diploid ones in the amount of the reducihg matters, such as a, scorbic acid, the reducing sugars, etc, which reduce KCIO, to KCIO, poisonous substance to plants.
