Effects of selected heavy metals (Pb, Cu, Ni, and Cd) in the aquatic medium on the restoration potential and accumulation in the stem cuttings of the terrestrial plant, Talinum triangulare Linn

Abstract

The heavy metal (Cu, Pb, Ni, and Cd) accumulation capacity of the stem cuttings of the terrestrial, ornamental plant, Talinum triangulare was assessed in hydroponic medium. The stem cuttings of T. triangulare, grew well in distilled water regenerating roots and aerial parts. On exposure to various concentrations of Cu, Pb, Ni, and Cd, a concentration dependent decrease was observed in the number of leaves produced and roots regenerated and an increase in the number of days required for the initiation of roots. The number of leaves produced showed an increasing trend in almost all treatment concentrations of Cu, Pb, Ni, and Cd with an increase in the duration of experiment, whereas, with an increase in the treatment concentration of metals a significant (P < 0.05) decrease was observed in the number of leaves produced. The number of days required for root initiation in metal solutions, however, increased with increasing concentration of Cu, Pb, Ni, and Cd. The root development was completely arrested from 10 mg l(-1) of Ni and 4 mg l(-1) of Cd. Compared to the control, a significant decrease was recorded in the number of roots produced in all treatment concentrations of Cu, Pb, Ni, and Cd. Pink colouration of metal solution consequent to leaching of plant pigment from T. triangulare was observed which was not persistent and disappeared after a few days. Decaying of stem was observed when exposed to Ni and Cd but not to Cu and Pb. Although, copper accumulation by T. triangulare at treatment concentration of 15 and 20 mg l(-1) exceeded 1,000 mg kg(-1) dry matter, necessary pot culture experiment is required before "T. triangulare" can be definitely classified as a Cu hyperaccumulator.

Coupling bioaccumulation and phytotoxicity to predict copper removal by switchgrass grown hydroponically

“…For example, results of the hydroponic studies conducted by Benzarti et al (2008) showed that the BCF of four plants decreased as the Cu concentration in solution increased from 1 to 1000 lM. A similar tendency was also observed for the terrestrial plant T. triangulare when it was exposed to various concentrations of waterborne Cu (Rajkumar et al 2009). In the present study, the BCF of switchgrass was calculated as 503, 341, 154, and 102, with Cu concentrations in solution of 0.5, 1.0, 2.0, and 5.0 lg mL -1 , respectively.…”

Potential role of Ceratophyllum demersum in bioaccumulation and tolerance of some heavy metals

“…Selection of plant species for metal removal is based on the plants which should have high tolerance to the contaminant and high capacity accumulation rate for the element and capability to accumulate several metals (Rajkumar et al, 2009). Ceratophyllum demersum is a submerged aquatic macrophyte belonging to Ceratophyllaceae family (Arber, 2010).…”

Growth response of the duckweed Lemna gibba L. to copper and nickel phytoaccumulation

“…heavy metals) from polluted mediums (Rai 2009;Susarla et al 2002). Selection of plant species for metal removal is based on the known of the tolerance and capacity accumulation of the species (Rajkumar et al 2009). For the good accumulation of metals, plants should have some of the following traits: (a) high tolerance to the contaminant, (b) high accumulation rate for the element, (c) capability to absorb high levels of contaminants, (d) capability to accumulate several metals, (e) high biomass production and (f) resistance to diseases and pests (Wanatabe 1997).…”