Effects of GLDA on cadmium absorption,accumulation and translocation ability of Pennisetum alopecuroides

【Objective】 The experimental objective was to explore the effects of the degradable chelating agent GLDA on the absorption, enrichment and transport of Pennisetum alopecuroides cadmium(Cd) when applied at different concentrations, aiming to provide a scientific basis for the full use of chelating agents and plants to repair Cd-contaminated soil.【Method】 P. alopecuroides was used as experimental material, and pot experiment was conducted to study the effects of different molar mass concentrations of GLDA0(control), 1, 2, 3, 4, 5 mmol/kgon the growth index, physiological index, the concentration of Cd in each part of P. alopecuroides. The correlation between GLDA concentration and the physicochemical properties of P. alopecuroides was analyzed.【Result】 The results showed that compared with the control, the plant height, root length and total biomass of P. alopecuroides increased first and then decreased with the increase of GLDA molar mass concentration, the plant height increased 8.23%, the root length increased 4.41% and the total biomass increased 7.75% with GLDA 2 mmol/kg. The chlorophyll a, total chlorophyll and chlorophyll a/b of P. alopecuroides increased firstly and then decreased, and reached the maximum value with GLDA 2 mmol/kg, which were 1.16, 1.09 and 1.19 times of those of the control treatment. Compared with the control, the bioconcentration factors(BCF) of P. alopecuroides under GLDA treatment increased and showed the order of root>leaf>stem. When the molar concentration of GLDA was 2 mmol/kg, translocation factor(TF) >1.00, the maximum value of PRF was 1.93. Correlation analysis showed that the concentration of GLDA was significantly negatively correlated with plant height, chlorophyll, aboveground biomass and underground biomass of P. alopecuroides(P<0.01, the same below), but positively correlated with underground Cd content.【Conclusion】 Comprehensive analysis showed that low concentration of GLDA can improve photosynthetic ef-ficiency, promote the growth of P. alopecuroides and increase its enrichment and transport capacity by promoting the production of chlorophyll, while high concentration can inhibit the growth of P. alopecuroides. The optimum molar mass concentration of GLDA for P. alopecuroides to remediate cadmium pollution is 2 mmol/kg, which can significantly improve the remediation efficiency of cadmium pollution.