[Cadmium Accumulation Characteristics of Different Heat Varieties Under Cadmium Stress].

In order to provide technical support for the safe utilization of heavy metal-polluted farmland, we screened wheat varieties with a low accumulation of Cd in grain via a pot experiment. For this purpose, we respectively investigated the enrichment and transport characteristics of Cd in various plant parts of 119 wheat varieties under the conditions of 1.5 mg·kg (low content) and 4.0 mg·kg (high content) Cd-contaminated soil and explored the correlation between the Cd content of different organs of wheat and the relationship between Cd content in soil and the uptake of Cd by wheat. The results showed that:① there were significant differences in the ability to accumulate and transport Cd in roots, stems, leaves, and grains of tested wheat varieties (<0.05). Under the condition of low Cd content, the Cd enrichment ability of each part of the wheat plant was as follows:leaf>stem ≈root>grain; under high-content stress conditions, the Cd enrichment ability of each part of the wheat plant was:leaf>root>stem>grain; under different content conditions, the Cd transport ability of each part of the wheat plant was:leaf>stem>grain. Cd content in the wheat shoot was positively correlated with total Cd content and ion-exchangeable Cd content in soil (<0.01) and was closely related to strong transpiration under the pot experiment. ② The correlation coefficient r of BCF of wheat roots, stems, leaves, and grain was -0.267 to -0.645, showing a very significant negative correlation (<0.01), indicating that with the increase in soil Cd content, the migration and accumulation degree of Cd in wheat plant organs showed a downward trend. Moreover, the negative correlation between BCF and soil Cd content in stems was significantly higher than that in roots, leaves, and grains, indicating that the enrichment of Cd in wheat plants largely depended on the accumulation and transportation of stems. ③ The correlation coefficient r of Cd content between the root and stem, root and leaf, root and grain, stem and leaf, stem and grain, and leaf and grain in low-and high-content groups was 0.450-0.763, showing a very significant positive correlation (<0.01), indicating that there was a close transport relationship among the wheat organs, and the degree of translocation from the root to stem and stem to leaf was higher than that from the stem to grain and leaf to grain. ④ Using cluster analysis and enrichment and translocation coefficient sequencing, this study screened 16 and 11 wheat varieties with low Cd accumulation under the soil cadmium content of 1.5 mg·kgand 4.0 mg·kg, respectively. Among them, Luohan 7 could be used as the optimal wheat variety with low Cd accumulation under the conditions of low-, medium-, and high-Cd content.