Interactive effect of heavy metals and temperature on the growth, and chlorophyll, saccharides and soluble nitrogen contents inPhaseolus plants

The effect of combinations of different concentrations of copper (Cu) and mercury (Hg) ions with different constant temperatures (T) onPhaseolus vulgaris plants was studied. Criteria investigated included shoot and root length, dry mass, chlorophyll content (Chl) and stability index (CSI), and contents of soluble (SS) and hydrolysable saccharides (HS), soluble proteins (SP) and total free amino acid (AA). Each of the factors (T, Cu and Hg) significantly affected the parameters tested with exception of T effect on Chlb content as well as on Chla/b ratio. Bifactorial interactions (T×Cu) or (T×Hg) were also significant, except the interaction (T×Hg) in shoot elongation, Chlb content and Chla/b ratio. Statistical treatment of the data lead to three findings: (1) temperature was dominant in affecting CSIa, shoot AA and root SS, (2) Cu and Hg had the predominant effect on growth parameters and Chl content, and (3) interactions (T×Cu and T×Hg) were dominant in affecting CSIb, shoot SP, and root HS.