The Effect of Temperature on the Conversion of Protochlorophyll to Chlorophyll a in Etiolated Barley Leaves.

riboflavin, thiamine, and carotene content of leaf blades was not statistically significant over a period of six weeks. In midribs and roots, the concentration of each of the vitamins decreased as the plants grew larger and the decrease was statistically significant for each vitamin except carotene, in midribs, and thiamine, in roots. Distribution of the whole plant content of carotene, riboflavin, and thiamine among plant organs did not change appreciably as plant dry weight increased, but there was a marked change in the distribution of ascorbic acid which rather closely followed the distribution of plant dry matter. In all experiments the total amount of each vitamin per plant was positively and significantly correlated with the total amount of plant dry matter. Increase in the total amount of vitamin per plant per unit increase in plant dry matter was characteristic for each vitamin and was not influenced by the environmental conditions under which the plants were grown. Regression equations derived for the estimation of the amount of each of the vitamins per plant from plant dry weight were applicable to plants weighing from 2 grams to 69 grams. LITERATURE CITED