The Effect of Fertilization and Mycorrhiza on Cadmium Uptake by Tobacco

The effect of fertilization and arbuscularmycorrhiza (AM) on cadmium (Cd) uptake by tobacco (Nicotianatabacum L.) was studied in a greenhouse pot experiment. Two tobacco varieties and five AM fungal isolates were included in this study. Each combination of tobacco variety × AM fungal isolate was compared in two fertilization treatments: a nutrient solution and a slow-release fertilizer. Unexpectedly, root colonisation levels were low for most treatments. They were lower in the treatments having received the slow-release fertilizer than in the treatments with the nutrient solution. Inoculation with two AM fungal isolates led to a significant reduction of the Cd concentration in tobacco leaves. However, the main outcome of this study was the important effect of the fertilization regime on the Cd concentration of tobacco leaves. For one variety, Cd concentration was decreased by 48-58% in the slow-release fertilizer treatment when compared to the nutrient solution treatment. The effect of the fertilization regime on leaf Cd concentration was thus clearly more pronounced than that of AM. Similar results were obtained for the other variety, although the decrease was less pronounced.