Screening of chili cultivars with low cadmium accumulation and analysis of their physiological properties of tolerance.

Chili (Capsicum annuum L.) is a widely eaten condiment that may accumulate the toxic element cadmium (Cd) from environments, thus presenting a human health risk. This experiment aimed to identify cultivars with low Cd-uptake characteristics that could be used to produce safe spicy food in Cd-contaminated soil. Five chili cultivars responses to Cd exposure in soils with 0.18 mg kg^-1 (CK), 2.88 mg kg^-1 (T1), 7.69 mg kg^-1 (T2), 16.72 mg kg^-1 (T3), and 33.46 mg kg^-1 (T4) in a greenhouse were compared. The results showed that Cd concentration in roots, shoots, and fruits of the cultivar Bolafengxiang was the lowest. Additionally, its biomass was not reduced compared to the CK, and both the enrichment factor (EF) and translocation factor (TF) were all lower than 1. Notably, under soil Cd concentrations of 2.88 mg kg^-1, the Cd content in the fruits of Bolafengxiang was 0.07 mg kg^-1, which is below the safety standard limit (0.1 mg kg^-1) for "Green Food Chili Products." This indicates its potential for low Cd accumulation. The above research indicates that selecting and cultivating low-Cd-accumulating chili cultivars is an effective approach to reduce Cd accumulation in edible parts, thereby ensuring agricultural food safety.