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 (Fagopyrum esculentum Mnch.) and white mustard (Sinapis alba L.) plants showed that the sub-apical and middle leaves, before they had reached their approximate final sizes, had the highest rates of ¹⁴CO₂ 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 ¹⁴CO₂ than analogous leaves of buckwheat plants. In the investigated leaves no close relationship between the intensity of ¹⁴CO₂ 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.