Reducing Cadmium Accumulation in Fresh Pepper Fruits by Grafting

Abstract

Contamination of vegetables with cadmium (Cd) is a worldwide problem. Three pot experiments were carried out to reduce the Cd content in fresh fruit of 52 Japanese pepper (Capsicum annuum L.) cultivars. The first experiment was carried out to select low Cd pepper cultivars after growing on a 2.1 Cd mg·kg⁻¹ contaminated soil. The second experiment was carried out to select low Cd-accumulating pepper rootstocks while the third experiment was carried out to evaluate grafting as a tool to reduce Cd in fresh peppers. The ability of pepper cultivars to accumulate Cd in fresh fruit was significantly different. The Cd content ranged from 0.018 to 0.088 mg·kg⁻¹ of fresh weight (FW). Among the pepper rootstocks cultivated in Japan, the cultivar ‘Daisuke’ was selected as a low-Cd accumulating rootstock. The grafting of cultivar ‘Ace’ onto ‘Daisuke’ rootstock reduced the Cd content by 40% in fresh peppers. However, other trace elements such as Fe, Mn, and Zn, which are important for human nutrition, were also reduced by 20%, 29%, and 42%, respectively.