Morphological and ecophysiological traits of kiwifruit plantlets (Actinidia deliciosa) under elevated CO2

One-year-old Actinidia deliciosa cv. Hayward were grown at normal and elevated CO2 concentrations to determine the effect of high CO2 on some morphological and ecophysiological traits of the plantlets. Plantlets exposed to elevated CO2 showed lower total fresh matter accumulation than control plants, had shorter shoots and fewer and smaller leaves than plantlets grown with normal ambient CO2; and had higher total percentage dry matterweight, specific leaf weight and higher levels of carotenoids and chlorophyll b. Correlation of the leaf area with the central vein length yielded an equation with which the leaf area could be calculated without the need of an area meter. The ecophysiological data on the leaves at different stages of growth revealed that kiwifruit did not derive any advantage from high CO2. Plantlets exposed to elevated CO2 had leaves with lower transpiration and stomatal conductance. The water use efficiency was higher in CO2-exposedleaves than in control leaves.