Screening of safe soybean cultivars for cadmium contaminated fields

The selection and breeding of Cd-safe cultivars (CSCs) has been used to minimize the influx of Cd into the human food chain. The pot-culture experiment combined with the field-culture experiment were conducted to screen out CSCs, i.e. the cultivars accumulating Cd at low enough level for safe consumption in their edible parts when grown in contaminated soils, were screened out and explored among the crop cultivars. We used 25 Chinese soybean cultivars in different Cd contaminated soils to assess the performance of this new method. Variations in uptake, enrichment, and translocation of Cd among these cultivars were studied to screen out soybean CSCs. The accumulation of Cd in the five soybean genotypes was lower than 0.20 mg kg^-1 under 1.0 mg Cd kg^-1 treatment, and the EF and TF were lower than 1.0. The field studies further identified that cultivar Shennong 10, Tiedou 36 and Liaodou 21 fit the criteria for CSCs, which were suitable to be planted in low-Cd (Cd concentration < 1.22 mg kg^-1) contaminated soils. The results can provide scientific methods for screening low-Cd accumulation in soybeans and can provide a path for controlling, treating and remedying Cd-contaminated agricultural soils to make grains safe for human consumption.