Tolerance of seven perennial grasses to high nickel in sand culture

• Published in: Environmental chemistry Vol. 7; no. 3; pp. 279 - 286
• Main Authors: Kopittke, P.M, Blamey, F.P.C, Kopittke, R.A, Asher, C.J, Menzies, N.W
• Format: Journal Article
• Language: English
• Published: Collingwood, Victoria: CSIRO Publishing 2010
• Subjects: nickel toxicity; phytoremediation; shoot growth; symptoms
• ISSN: 1448-2517; 1449-8979
• DOI: 10.1071/EN09100

Environmental context.High concentrations of Ni in soil may occur either naturally or as a result of human activities. We used a sand culture system to investigate the suitability of seven perennial grasses for the revegetation of Ni-contaminated sites. This study provides information on the toxic effects of Ni on plant growth and gives consideration to the health of animals consuming these plants, thereby increasing the accuracy of risk assessments. Abstract.Although grasses are commonly used to revegetate disturbed areas, comparatively little is known regarding the tolerance of perennial grasses to toxic levels of trace metals. A sand culture experiment was conducted to investigate the tolerance of seven perennial grasses to high concentrations of Ni. The activity of Ni²⁺ in solution that resulted in a 50% reduction in shoot growth ranged from 50 µM for Sabi grass (Urochloa mosambicensis (Hack.) Dandy cv. Saraji) to 13 µM for curly Mitchell grass (Astrebla lappacea (Lindl.) Domin). In most grasses, growth in the high-Ni²⁺ treatments resulted in shoot Ni concentrations at or above the toxicity threshold for consumption by cattle (100 µg Ni g⁻¹). Based upon their tolerance to Ni, and the extent to which they translocate Ni to the shoots, Sabi grass, signal grass (Brachiaria decumbens Stapf. cv. Basilisk) and buffel grass (Cenchrus ciliaris (L.) cv. Biloela) appear well suited for the phytostabilisation of Ni-contaminated sites in subtropical and tropical regions.