玉米//龙葵间作对玉米生长及镉分布特征的影响OA

This study aimed to explore the functional mechanism of Zea mays//Solanum nigrum intercropping for simultane-ous production and remediation in cadmium-polluted farmland.A pot experiment was set up with two cadmium concentrations(0 and 5.0 mg·kg-1)and two planting modes,including monoculture and intercropping.We investigated the impacts of cad-mium stress on maize growth indexes,antioxidant enzyme activities,and antioxidant substance contents,and analyzed the total cadmium content,chemical forms,and subcellular distribution of cadmium in a soil-maize system.The results showed that under 5.0 mg·kg-1 cadmium stress,compared with monoculture,intercropping markedly raised maize plant height,chlo-rophyll content,and single-ear weight by 9.1%,4.7%,and 30.1%,respectively.The activities of Catalase,peroxidase,and superoxide dismutase in leaves were significantly elevated,whereas glutathione S-transferase activity and malondialdehyde and hydrogen peroxide contents declined obviously.In the intercropping soil,the contents of weak acid-extractable and resid-ual cadmium increased by 23.7%and 46.4%,respectively.The cadmium contents of all chemical forms and subcellular com-ponents in maize roots rose significantly.In contrast,the total cadmium contents in stems,leaves,and grains decreased by 16.4%,5.0%,and 35.0%,respectively.Correlation analysis indicated that the residual cadmium content in maize leaves had a significant positive correlation with plant height and chlorophyll content.In conclusion,maize//black nightshade intercropping improves maize antioxidant defense and photosynthetic capacity and facilitates cadmium form transformation and compart-mentation.It realizes the coordinated effects of detoxification and safe maize production,and provides a theoretical reference for the green remediation of cadmium-contaminated farmland.