Effects of mutual intercropping on cadmium accumulation of Solanum photeinocarpum Nakamura et Odashima and its post-grafting generations

The cadmium (Cd) contaminated agricultural soil has become serious in recent years, but it will take long time for Cd-hyperaccumulator to remedy. To speed up the remediation of agricultural soil and achieve the safe agricultural production as soon as possible, the potential Cd-hyperaccumulator Solanum photeinocarpum Nakamura et Odashima was intercropped with its post-grafting generations in Cd-contaminated soil. Intercropping increased the biomass, Cd contents and Cd extractions of S. photeinocarpum and its post-grafting generations in the pot and field experiments. Both the whole plant or shoot biomass and the Cd extraction by whole plant or shoot in intercroppings had a linear regression relationship with that in monocultures. In the field experiment, intercropping increased the shoot Cd extraction of S. photeinocarpum by 9.86%–40.06% compared with the monoculture. Intercropping increased the content of chlorophyll, activity of superoxide dismutase, activity of catalase, and soluble protein content of S. photeinocarpum and its post-grafting generations but reduced their peroxidase activities in the pot experiment. Therefore, intercropping S. photeinocarpum with its post-grafting generations can improve their phytoremediation ability, and the best choice is S. photeinocarpum intercropped with its post-grafting generation of wild potato rootstock. Novelty statementIntercropping Solanum photeinocarpum Nakamura et Odashima with its post-grafting generations could mutually promote the Cd accumulation in the two types of plant species, and improve their phytoremediation ability for remedying the Cd-contaminated soil.