Abstract:

To reduce cadmium (Cd) pollution in paddy fields in Xiangjiang River Basin in Hunan Province, peanut was planted as expected replacing crop in Cd polluted paddy fields in Changsha and Xiangyin City. 5 largeseed peanut varieties were selected and 2 different cultivation methods (open field and plastic film cultivation) were tested. By investigating peanut Cd uptake, enrichment and transport, the Cd concentration and translocation in pad? dy fields were studied. Results showed that Cd contents in vegetative peanut organs (roots, stems and leaves) were higher than in reproductive ones (shells and seeds). Cd contents were significant different among varieties. Stem had the highest (5.413-8.859 mg·kg-1) content, shells and seeds had the least (0.523-1.326 mg·kg-1). Among them, the Cd content in seeds exceeded the standard of NY/T 1067-2006, which suggested certain risk of seed food. Under film mulching cultivation, Cd contents in some organs (including stems, leaves, pegs, shells and seeds) were re? duced, although the accumulation of both plant dry matter and plant total Cd accumulation were increased. Under film mulching, Cd concentration coefficient of vegetative organs (root, stem and leaf) was above 2.5, which was high?er than those of reproductive organs (shells and seeds). Cd transfer coefficients were in the order as: root to stem> stem to leaf > shell to seed> peg to shell> stem to peg. Cd content of peanut oil ranged from 0.012 to 0.074 mg·kg-1, which indicated safe oil on Cd fields according to the standard. In summary, dry matter accumulation and Cd con? tent of aboveground could be used as indicators for high Cd accumulation. Among the 5 genotypes, 09-3106 was the highest individual Cd accumulation variety. And the peanut film mulching cultivation was recommended for Cd re? duction of paddy fields.

Key words:  , peanut；variety；paddy field；film；cadmium；concentration；translocation