Studies on Vitamin C. XVIII

The Effect of Light upon the Production of Vitamin C

Abstract

According to Fürst, Chick and Hume, Heller, Kucera, it is an established fact that vitamin C is synthesized by the process of germination. The writer, also reported that germination of various seeds in the sun light produced a notable amount of vitamin C, and showed that although, light was not absolutely necessary factor for the production of vitamin C, but its content was affected by the light, and the differece of content was more clearly defied in sprouts germinated for a long time.
In the 17th report, the writer stated that barley produced antiscorbutic vitamin even in the dark, but existence of light had some influence upon the production, for vitamin C was remarkably increased in barley cultivated in the sun light.
The writer examined the effect of light upon the production of vitamin C with barley germinated, radish grown for 35 days and Unshu orange. Results obtained were as follows.
(1). In sprouts not manured during germination was effected by the light, the longer the seeds germinated, the greater the difference of content.
(2). The production of vitamin C in sprouts manured was also clearly affected by the light. To compare the content of the sprouts germinated in the dark with that of the sprouts germinated in the sun light, the former was only about 1/4 of the latter.
(3). One part of barley was covered to grow in the darkStudies on Vitamin C. XVIII. 65field, until the barley not covered extends to the length of 4 feet, to see whether there is an influence of light upon the production of vitamin C, according to the result, the exsistence of light influences upon the production of vitamin C, for, the production was about quadruple in the light as much as in the dark.
(4). The radishes germinated were grown for 15 days in the sun light, then, one part of them was covered for 20 days to grow in the dark, the other part was grown in the sun light. The content of vitamin C of the radish covered was about 1/5 of the other.
(5). Vitamin C content of uncovered orange was twice as much as that of covered one, therefore, the effect of light was very little.
(6). The production of vitamin C during life of plant is affected by the light.
(7). Light is not the absolute factor for the production of vitamin C during life of plant, for it was produced even in the dark, but the existence of light has some influence upon the production.