Selection and breeding of pollution-safe cultivars (PSCs)-An eco-friendly technology for safe utilization of heavy metal(loid) contaminated soils

The ubiquitous heavy metal(loid) pollution in farmlands poses a major threat to food safety and human health, which has caused wide public concern. In recent years, the cultivation of pollution-safe cultivars (PSCs), i.e., cultivars that accumulate pollutants at low enough levels for safe consumption, has been considered as a promising approach to ensure food safety in low to medium level contaminated soils. In this review, we dissected the theoretical basis and advances for the selection and breeding of PSCs, and deeply discussed the modern and traditional breeding approaches, particularly the integration of marker-assisted selection (MAS) and gene editing practices for the selection and cultivation of PSCs. Furthermore, we proposed a practical technical framework for the safe use of heavy metal(loid) contaminated soils via enhancing PSCs with several agronomic measures such as organic and inorganic amendments, biochar application, and co/pre-cultivation with hyperaccumulating plants. Finally, we remarked upon the future directions in the selection and cultivation of PSCs, as well as their strengthening measures and relative mechanisms. The review has a scientific significance for further exploration of PSCs among crops and their practical application in field. (C) 2021 The Authors. Published by Elsevier B.V.