Changes in 14CO2 absorption rates by the successive leaves in buckwheat and white mustard plants of various ages

Abstract

The experiments with different-aged buckwheat (<i>Fagopyrum esculentum</i> Mnch.) and white mustard (<i>Sinapis alba</i> L.) plants showed that the sub-apical and middle leaves, before they had reached their approximate final sizes, had the highest rates of <sup>14</sup>CO<sub>2</sub> absorption. The intensity of this process decreases in each leaf with age of the plant. White mustard leaves showed a little higher absorption rate of <sup>14</sup>CO<sub>2</sub> than analogous leaves of buckwheat plants. In the investigated leaves no close relationship between the intensity of <sup>14</sup>CO<sub>2</sub> assimilation and chlorophyll a and b concentration was observed. Some possible reasons for the higher intensity of photosynthesis in the sub-apical leaves are discussed.