Abstract:

The aims are to clarify the cadmium accumulation and transport characteristics of buckwheat in farmland with different cadmium background values, and lay the foundation for the phytoremediation of cadmium contaminated farmland. Using 8 buckwheat varieties (lines) as materials, multi-point experiments were carried out in 9 cadmium-contaminated farmlands to detect cadmium contents in buckwheat roots, stems and leaves, and grains. The results showed that buckwheat had a strong ability to absorb and accumulate cadmium. Within a certain range, as the soil cadmium content increased, the cadmium content of buckwheat grains first showed an increasing trend, and then the cadmium content no longer increased significantly. The absorption law of cadmium in different parts of buckwheat at maturity stage was as following: stems and leaves>roots>grains. The cadmium enrichment coefficient of stems and leaves was 2.03-5.52, the cadmium enrichment coefficient of roots was 1.03-4.08, and the cadmium enrichment coefficient of grains was 0.15-0.92. The cadmium transport coefficient of roots-stems and leaves was 1.34-2.30, and the cadmium transport coefficient of stems and leaves-grains was 0.07-0.22. The results indicate that buckwheat has obvious cadmium accumulation capacity and strong cadmium transport capacity, and could be used as a potential plant for remediation of heavy metal contaminated soil, and soil cadmium is mainly transported and accumulated in stems and leaves.

Key words: buckwheat, cadmium pollution, phytoremediation, accumulation, transport