Effect of EDTA Application on Lead and Zinc Uptake and Germination of Thlaspi caerulescens L. in a Contaminated Soil

Pot experiment was carried out to investigate the effects of ethylenediaminetetraacetic acid (EDTA) on some morphological characteristics of Thlaspi caerulescens L., and also on the accumulation of lead (Pb) and zinc (Zn) in roots and shoots of T. caerulescens L.. Experiments were then set up in three treated pots with doses of ۳, ۶ and ۹ mmol kg-۱ of EDTA and control pots (C: uncontaminated soil and W: contaminated soil). The results indicated the significant effect of EDTA on morphological characteristics and accumulation of heavy metals in the plant (P<۰.۰۵). Data revealed that the maximum of germination (۹۹.۱۱ and ۹۶.۰۰%), maximum of root length (۷۳.۳۱ and ۷۰.۱۴ mm) and maximum of shoot length (۵۱.۶۴ and ۴۴.۱۴ mm) and maximum of biomass weight (۶۱.۳۱ and ۵۲.۱۸ mg) were achieved by C treatment followed by W treatment. The maximum bioconcentration factor (۳.۵۷) and translocation factor (۰.۸۹) was observed on ۹ mmol kg-۱ EDTA. In addition, the effect of EDTA on Tolerance Index (TI) showed that the TI decreased with increasing doses of EDTA. The findings indicated that the study species tolerated heavy metals concentration. EDTA had potential to promote the uptake of heavy metals for T. caerulescens L., butwith respect to non-significant differences between ۶ mmol kg-۱ EDTA and ۹ mmol kg-۱ EDTA treatments. Thereore, low dose of EDTA suggested to be applied because of its environmental risk.

کلیدواژه ها:

Chelating agents ، Heavy metals ، Morphological characteristics ، Phytoextraction