| Popis: |
PurposeThe physiological mechanism and phytoremediation effects of heavy metal pollution by local desert plants, namely, Kochia scoparia, Chenopodium glaucum and Atriplex centralasiatica, around tailings were investigated. MethodsTwo different types of local soils (native soil and native soil + tailings, which are labeled CK and T, respectively) were used for potting experiments in the open, and the photosynthesis performance, chlorophyll content, hydraulics and stem anatomy of the potted plants were analyzed. The collection of soil samples has been approved by the soil resources management department of the local government.ResultsIt was found that the chlorophyll content, photosynthetic rate and transpiration rate decreased but the chlorophyll a and b (Chl a/b) and intercellular CO2 concentration (Ci) values increased in Kochia scoparia under complex heavy metal stress. Nonstomatal restriction led to a decrease in the net photosynthetic rate (Pn) and damage to the chloroplasts. Additionally, four hydrodynamic parameters were elevated under heavy metal stress along with a decrease in duct density and diameter and a significant thickening of the duct wall. Under heavy metal stress, the changes in the chlorophyll parameters of Chenopodium glaucum, Atriplex centralasiatica and Kochia scoparia exhibited the same pattern, with stomatal restriction causing a decrease in Pn and Ci and a significant increase in the leaf specific conductance, hydraulic conductivity, and duct diameter. ConclusionsAtriplex centralasiatica is the dominant desert plant in the region and demonstrates good adaptability and heavy metal accumulation under the stress of heavy metal tailings; therefore, it is a good candidate for tailings remediation in the Jinchang desert mining area. |
