Abstract
Phytoremediation is effectively used to remove heavy metals from soil. In this research Chenopodium album and
Chenopodium murale were evaluated for their comparative potential to phytoremediate increased (0-750 μM) cadmium (Cd)
from soil. Both the Chenopodium species showed wide difference for Cd tolerance. Chlorophyll (Chl) a was at par with
control in at 250 µM Cd C. album, but was reduced in C. murale. Chl b was less reduced by Cd in C. album than in C. murale
resulting in an increased Chl a:b ratio. Likewise, carotenoids were reduced minimally in C. album and greatly in C. murale.
Although soluble phenolics were reduced in both the species, a markedly greater accumulation of anthocyanins was noted in
C. album at all Cd levels. Greater levels of Chl a and anthocyanins and minimal Chl b contents were important to Cd
tolerance in C. album. The C. album showed a minimal reduction in K+
, steadier Ca2+, SO4
2-
-S, and PO4
3-
in shoot and root,
NO3
-
in the shoot. C. album accumulated more Cd in shoot while C. murale in root, and showed greater capacity to adjust
metabolites and accumulate macronutrients. From the increased shoot Cd contents, whilst showing better growth, we infer
that metabolic changes could help bind and sequester excess of Cd in the vacuole, and thus better Cd tolerance. Greater seed
germination, reduced post-germination mortality and enhanced growth of mungbean (used as successive crop) substantiated
that C. album is a better phytoremediator of Cd than C. murale. In crux, better growth and Cd-phytoremediation by C. album
may have great implications for agricultural practices.
