Effects of different rootstocks on cadmium accumulation characteristics of the post-grafting generations of <i>Galinsoga parviflora</i>

Abstract

A pot experiment was conducted to study the effects of different rootstocks on the cadmium (Cd) accumulation characteristics of the post-grafting generations of Cd-hyperaccumulator <i>Galinsoga parviflora</i> plants. Five treatments, ungrafted and <i>G. parviflora</i> seedlings grafted on the rootstocks of <i>Kalimeris indica</i>, <i>Senecio scandens</i>, <i>Conyza canadensis</i>, and <i>Artemisia sieversiana</i>, were utilized. The four rootstock grafts decreased the shoot biomass of the <i>G. parviflora</i> post-grafting generation compared with ungrafted. The <i>K. indica</i> and <i>S. scandens</i> grafts increased the Cd concentration in shoots of the <i>G. parviflora</i> post-grafting generation by 15.06% and 14.40%, respectively, compared with ungrafted, while the <i>C. canadensis</i> and <i>A. sieversiana</i> grafts had no significant effects. <i>K. indica</i> grafts increased the amount of Cd extracted by shoots of the <i>G. parviflora</i> post-grafting generation by 10.59% compared with ungrafted, while the other treatments resulted in decreases. Compared with ungrafted, the different rootstocks had no significant effects on the photosynthetic pigment content of the <i>G. parviflora</i> post-grafting generation, and only <i>C. canadensis</i> grafts increased the superoxide dismutase activity level, while only <i>K. indica</i> grafts increased the peroxidase activity level. Therefore, the <i>K. indica</i> rootstock could increase the phytoremediation capability of <i>G. parviflora</i> post-grafted plants grown in Cd-contaminated soil.