Screening of rice varieties with low cadmium accumulation and evaluation of their performance in rice fields with cadmium exceeding standard

【Objective】Screened rice varieties with low cadmium accumulation and carried out evaluation research on rice field performance with cadmium exceeding the standard to provide variety and data reference for the production of safe rice in Guangxi’s medium and low-level cadmium-polluted rice fields.【Method】114 breeding materials of low-cadmium rice varieties（V1-V114）were selected as the test objects，and the target materials with excellent comprehensive properties and low cadmium accumulation were selected from the target materials；field tests and pot experiments were carried out to verify the target materials，their agronomic characteristics and polished rice cadmium content were tested at different test sites in Guangxi.【Result】Among the 114 tested materials in the preliminary screening test，except for the cadmium content in polished rice of V102 which was lower than the lowest detection value，the cadmium content in polished rice of the remaining 113 rice breeding materials ranged from 0.01 to 0.35 mg/kg，with an average value of 0.10 mg/ kg. The material V111 with excellent comprehensive properties and low cadmium content in polished rice was screened （named Guiyu 12 after certification）. When Guiyu 12 was planted in fields with medium and low levels of cadmium pollution，the cadmium content of polished rice（0.01-0.10 mg/kg）did not exceed the limit specified in the national standard GB 2762-2017 National Food Safety Standard Limits of Contaminants in Food（0.20 mg/kg）. The pot experiment results showed that under the conditions of pH 5.0 and soil cadmium content of 3.0 mg/kg，the cadmium content（0.34 mg/kg）of Guiyu 12 polished rice was at risk of exceeding the standard. The soil cadmium content in each experiment had a significant impact on some agronomic indicators of Guiyu 12（P<0.05），but it belonged to the normal fluctuation range of the variety planting，and the comprehensive impact on rice quality and yield was limited.【Conclusion】A low cadmium accumulation variety Guiyu 12 is selected from 114 rice materials. After years of multi-site experiments，it is verified that the cadmium content in rice produced by Guiyu 12 does not exceed the standard in the middle and low-level cadmium-contaminated rice fields，and the low cadmium accumulation traits in grains are relatively stable. The performance of comprehensive traits is less affected by soil cadmium content，which can be applied and popularized in Guangxi rice fields with low and medium cadmium pollution.