INFLUENCE OF TEMPERATURE ON THE VITAMIN CONTENT OF GREEN PLANTS

Abstract

Change in the temperature with seasons is such an important factor in plant growth that its influence on the vitamin content of plants deserves a thorough investigation. Yet very few such investigations have been made and all but one of these have been concerned with ascorbic acid. One of the peculiarities of these investigations has been that they do not agree as to the effect of temperature on the concentration of ascorbic acid in plants. Hamner et al. (5) found that tomato fruits produced at a temperature of 78? F (26? C) had a higher ascorbic acid content than fruits produced at 63? F (17? C), while ?berg (1) states that young tomato plants grown at 15.5? C had a 30% higher content of ascorbic acid than plants grown at 23? C. Re?d (8) found a lower concentration in cow pea seedlings grown at 29? than at 24? C and Moldtmann (7) noted that 10-day-old Vicia Faba seedlings had nearly twice as much ascorbic acid at 26? as at 14? C, whereas Pisum sativum seedlings had a much lower vitamin content at 26 than at 14? C. Avena sativa seedlings showed no essential difference at the two temperatures. Somers et al. (10) working with discs of turnip leaves floated on nutrient solution found that a higher concentration of ascorbic acid was obtained in discs grown at 24? C than in discs grown at 14? C. Rodahl (9) states that Empetrum nigrum has a higher concentration of ascorbic acid in northeast Greenland than in southeast Greenland. Presumably the former region has a lower temperature than the latter. Mitchell and Houlahan (?) reported a mutant of Neurospora which in order to make satisfactory growth has to be supplied with riboflavin at 28? C but not at lower temperatures. Wolf (11) found that excised leaves of Bryophyllum calycinum lost ascorbic acid at a temperature of 20? but not at 7? and 37? C.