CHROMIUM TOXICITY IN HYBRID EUCALYPTUS (<i>EUCALYPTUS UROPHYLLA</i>S. T. BLAKE X<i>GRANDIS</i>W. HILL EX. MAIDEN) CUTTINGS

Abstract

Abstract A greenhouse experiment was carried out to evaluate chromium (Cr) toxicity in urograndis (Eucalyptus urophylla S. T. Blake x grandis W. Hill ex. Maiden). Chromium nitrate was amended to Clark's nutrient solution (0.00, 0.04, 0.08, 0.16, 0.32 and 0.64 mmol L−1 Cr), which was used to breed one urograndis cutting per pot (four replications). Regression analysis revealed that Cr rates of 0.08 mmol L−1 or higher significantly decreased (P < 0.01) dry matter yield of shoot and root. Chromium accumulation order in plant was: root > stem > leaves. Critical Cr toxicity level in leaves was 0.74 mg kg−1. Uptake and translocation of nutrients were affected differently by Cr. Mostly have their uptake reduced due to root damage. Magnesium, iron and manganese translocation increases, supposedly to maintain normal photosynthetic activity. Wilting is the main visual symptom of Cr toxicity. Urograndis may be suitable for contaminated sites phytostabilization and receive industrial waste fertilization. Keywords: heavy metalsnutrient translocationnutrient uptakephytoremediationurograndis