抄録
Yamasaki, one of the authors, has once reported that wheats are less resistant to the toxic action of chlorate than spring ones, and he attributed the phenomenon to the difference in the contents of reducing substances such as glucose, aldehydes etc. in plant tissues. The present authors studied the interrelations among the content of vitamin C, one of the reducing substances in plant tissues, intensity of winter nature and chlorate resistance of varieties in wheat. Experiments were made with shoots germinated in Petri-dishes with pure water, employing 6 varieties varying in winter nature intensity. The relations of the vitamin C content to the winter nature were found as follows : 1) In the experiments conducted in winter, the higher the intensity of winter nature of the variety was, the more vitamin C was proved, under natural condition as well as in the dark. 2) In spring or summer, however, there was no correlations between these two characters. 3) When the temperature either or both in the daytime or at night was low, the results similar to those in the winter experiments were obtained, that is, a significantly high positive correlation wad represented (cf. Table 1, 2). From these facts and other results, the followings should be extracted : In order that the above-noted correlation between these two characters is presented, low temperatures are necessary. The light condition or the difference in temperature between the daytime and the night has no effect on such relation. The resistance to the toxic action of chlorate of the same varieties was tested simultaneously. A high negative correlation was recognized between the resistance and the winter nature intensity, regardless of temperature in the daytime or at night. (cf. Table 3). Considering of the results of the vitamin C determinations and the chlorate resistance tests, the negative correlation is recognized between the chlorate resistance and the vitamin C content, except when the temperatures both in the daytime and at night are high, under which condition the chlorate resistance seems to be affected by some uncertain factors other than vitamin C.
