Effects of self-rooted grafting on growth and cadmium accumulation in post-grafting generations of soybean ( Glycine max )

A study was performed to determine whether self-rooted grafting decreases cadmium (Cd) accumulation in post-grafting soybean ( Glycine max (Linn.) Merrill) generations. Pot experiments were performed using ungrafted (UG) seedlings, self-rooted grafting from the same soybean seedling (SG), self-rooted grafting from two soybean seedlings at the same growth stage (TG), and self-rooted grafting from two soybean seedlings at different developmental stages (DG). Growth and Cd accumulation in three post-grafting soybean generations were assessed. In the SG treatment, only the second post-grafting generation had increased shoot biomass and only the first post-grafting generation shoots had decreased Cd contents. The seed Cd content, soluble protein content, and antioxidant enzyme activity were not significantly affected in three post-grafting generations. In the TG and DG treatments, shoot biomass, soluble protein content, and antioxidant enzyme activities were increased, and the shoot and seed Cd contents were decreased in three post-grafting generations. The seed Cd contents in the first, second, and third post-grafting generations were 15.00%, 9.46%, and 12.44%, respectively, lower in the TG than UG treatments. The seed Cd contents in the first, second, and third post-grafting generations were 32.73%, 27.03%, and 32.22%, respectively, lower in the DG than UG treatments. Different grafting methods promoted growth and decreased Cd accumulation to different degrees in three post-grafting generations. Grafting seedlings at different developmental stages had the strongest effects.