EFFECT OF SAND CULTURE AND SODIUM CHLORIDE ON GROWTH PHYSICAL STRUCTURE AND ORGANIC ACID METABOLISM IN BRYOPHYLLUM PINNATUM

Bryophyllum pinnatum, a classical example of Crassulacean Acid Metabolism, was grown in sand and soils as well as in increasing concentrations of chloride and sulphate ions to test the effect of rooting medium and salts on growth, physical structure of leaves and on organic acids. Plants grown in sand medium show fewer and smaller stomata, a shorter and profusely branched root system and also a decrease in organic acid metabolism, as compared with plants grown in garden soil. This indicates that the subtratum plays an important role in controlling growth, physical structure of leaves and Crassulacean Acid Metabolism. The presence of chlorides tends to produce thicker leaves which have more organic matter and less moisture. Increase in NaCl-concentration retards growth and also affects CAM. In plants treated with 0.04 M NaCl there is a stimulation in organic acid synthesis which results in higher TAN values. Another interesting observation is that the development of a succulent habit is due to effect of chlorides and not by sulphate or sodium ions. © 1969 Martinus Nijhoff.