Effect of cadmium on plant biomass and cadmium accumulation in amaranthus (Amaranthus tricolor) cultivars

Abstract

An experiment was conducted during 2006–08 to find out the effect of cadmium on plant growth and its accumulation in different amaranthus (Amaranthus tricolor L.) varieties. Three amaranthus cultivars, namely Local, ‘Arka Arunima’ and ‘Arka Suguna’ were evaluated for their Cd tolerance and accumulating capacity in greenhouse on sandy loam soil. Variable levels of Cd were created through the application of CdCl2 @ 0 (control), 50, 100 and 200 mg Cd/kg soil. Fresh and dry biomass yield of shoots and roots in all the cultivars decreased with increased Cd levels. The relative reduction in fresh biomass yield of cultivar followed the order: Local> ‘Arka Suguna’> ‘Arka Arunima’. Significant reduction in the biomass of Local was recorded at applied Cd level of 50 mg/kg where as percentage reduction in biomass was lower in ‘Arka Arunima’. The Cd content of foliage increased with increase in soil Cd levels in all the cultivars. However, the concentration of Cd in ‘Arka Arunima’ was highest at all levels of applied Cd . This cultivar accumulated 43.5% more Cd than that in Local and 25.8% more Cd than that in ‘Arka Suguna’ at soil Cd level of 50.0 mg/kg. At highest soil applied Cd level of 200 mg/kg the Cd concentration in ‘Arka Arunima’ was 16.3 and 13.7% more than that in Local and ‘Arka Suguna’ respectively. Local cultivar accumulated relatively lower levels of Cd and this cultivar can be preferred for cultivation in high Cd soils.