Abstract: The effects of CO2 concentration on the morphological and anatomical characters of soybean (Glycine max) leaf were investigated by means of light microscopy and SEM. It was noticed that exomorphology did not show dramatic change, while stomatal density decreased with increasing CO2 concentration. Under SEM, no epicuticular wax was observed on both abaxial and adaxial sides of the control group as well as on adaxial side of the treatment group. However, leaf surface of abaxial side was noticed to be densely covered with microasterisk epicuticular wax when they were exposed to CO2-enriched environment. The epicuticular wax deposition was present in equal abundance on both stomatal and nonstomatal areas. Furthermore, leaf thickness increased significantly due largely to the origin of an extra layer of palisade in the treatment group. The results confirmed that CO2 enrichment might enhance cell division and induce greater quantity of epicuticular wax.

Key words: Soybean, Foliar structure, CO2 concentration