Characterization of Selenium Accumulation of Different Rice Genotypes in Chinese Natural Seleniferous Soil

In this study, the difference of Se content in brown rice of different rice genotypes was evaluated on natural seleniferous soil. Firstly, the Se content of brown rice in 80 rice germplasm resources was determined, which ranged from 0.0249-0.1426 mg/kg, showing obvious differences. Next, two cultivars with a significant difference in Se content in brown rice, i.e., cv. Wuyangeng (high) and cv. IR68144 (low), were used to study the distribution pattern of Se in different organs. Moreover, the physiological mechanism of the Se content diversity in brown rice of the two cultivars was explored preliminarily. The results showed that the Se content of cv. Wuyangeng was 2-3 times higher compared to cv. IR68144. However, the Se contents of cv. IR68144 root and leaf were significantly higher than that of cv. Wuyangeng under both natural soil environment and artificial nutrient solution culture. Cv. IR68144 also had a stronger root Se accumulation coefficient and shoot Se transfer coefficient. Consequently, it can be inferred that the stronger Se transfer ability from stem to grain was the key reason for the higher Se content in brown rice cv. Wuyangeng than in cv. IR68144.