PHOTOSYNTHETIC ACTIVITY OF SOYBEAN PODS AT DIFFERENT GROWTH STAGES COMPARED TO LEAVES

Abstract

Soybean (Glycine max (L). Merr. cv. Wye) pods at different growth stages (from 25 to 50 mm long) showed gas exchange in both light and dark. Oxygen (O2) production in the light did not exceed O2 consumption in the dark, indicating photosynthetic activity in the pod to be limited. On a fresh weight basis, leaves photosynthesized 6.3–7.4 times more actively than pods. However, on a chlorophyll basis, the pods had 1.5–1.8 times greater photosynthetic activity than the leaves. Leaves had 9.2–12.4 times greater chlorophyll concentration than pods. Scanning electron micrographs of pods indicated that stomates were present at early stages of growth, were open, and were probably functional in the intact tissue.