EFFECTS OF POTASSIUM ON THE NITROGENOUS CONSTITUENTS OF ANANAS COMOSUS (L.) MERR

Abstract

High-potassium cultures (205 mg. per l.) compared with low- potassium cultures (4 mg. per l.), supplied with equal amounts of nitrogen either as nitrate or ammonium, modified the relative amounts of different nitrogenous fractions in the tissues of A. comosus. The data indicate that the physiological function of potassium in the conversion of soluble organic nitrogen fractions to protein nitrogen in high-potassium cultures is more noticeable in the stem than in the highly differentiated tissues of fully expanded leaves. In the leaves protein-N was higher in the low- potassium than high-potassium cultures. The higher content of protein-N in the stems of the high-potassium than low-potassium cultures is attributed to the conditions in the peripheral and apical regions of the stem which, composed mostly of meristematic tissues and possessing potential growth activity, require greater quantities of proteins for the regeneration of protoplasm than similar tissues of the low-potassium cultures which lack equally great growth potentialities. [From authors' summary.]