Effects of Intercropping Patterns on Cadmium Tolerance of Perilla Frutescens and Soybean

In this study, we intercropped hyperaccumulator Perilla frutescens with soybean to explore the effects of intercropping under cadmium stress based on the physiological growth indexes of plant, cadmium absorption capacity, and soil cadmium forms Experiments showed that compared with mono-cropping, intercropping soybean’s biomass, catalase (CAT) activity, peroxidase (POD) activity, total chlorophyll and net photosynthetic rate were significantly increased by 1042%~10658%, 1578%~7381%, 1345%~2337%, 376%~1500% and 7121%~31278%, while P frutescens’s significantly decreased by 9387%~9507%, 1562%~2572%, 12056%~15331%, 715%~756% and 3056%~5076% Under 5 and 10 mg kg-1 Cd treatments, the Cd content in roots, stems, leaves, pods and grains of intercropping soybean decreased significantly by 1072%~3174%, 1488%~2168%, 1995%~3413%, 2222%~5270% and 791%~1786% along with enrichment coefficient decreasing by 1486%~2787%, while those of P frutescens significantly increased by 8700%~2141%, 948%~2155%, 2305%~3766% and 1818%~9412% along with enrichment coefficient significantly increasing by 2000%~7775% Additionally, citric acid, succinic acid, oxalic acid and tartaric acid worked importantly in heavy metal detoxification in plants Strikingly, the content of soil exchangeable Cd (EXC) under intercropping was the highest, even higher than that of mono-cropping soybean and P frutescens, which accounted for 37%~42% under the same stress condition Therefore, intercropping Perilla frutescens with soybean provide a potential strategy for Cd phytoremediation