不同花生品种对稻田镉富集及转运的研究

为研究湖南湘江流域稻田镉（Cd）污染治理方法，筛选稻田替代种植作物，于长沙县和湘阴市受污染稻田 改种花生，选用5个大果品种，设置2种（露地、覆膜）栽培方式，研究品种与栽培方式组合下对稻田Cd吸收、富集及 转运的影响。结果表明：稻田花生营养器官（根、茎、叶）Cd含量较高，生殖器官（果壳、籽仁）Cd含量较低，且品种间有明显差异。5 个花生品种的组织器官中Cd 含量最高的是茎（5.413~8.859mg·kg-1），果壳和籽仁最少（0.523~ 1.326mg·kg-1），但是籽仁Cd含量超出NY/T 1067-2006标准的规定值，食用安全存在风险。覆膜栽培尽管降低了花生茎、叶、果针、果壳及籽仁等的Cd含量，但提高了植株干物质重和Cd总积累，其中，营养器官（根、茎、叶）Cd富集系数高于2.5，生殖器官（果壳、籽仁）Cd富集系数为0.8~1.7。不同部位间Cd转移系数大小顺序为：根→茎秆>茎秆 →叶>果壳→籽仁>果针→果壳>茎秆→果针。不同品种的花生油中Cd含量范围在0.012~0.074mg·kg-1，符合标准， 因此花生油食用是安全的。以地上部单株干物质积累量及其Cd含量作为高镉积累筛选指标，5个品种中09-3106 的单株可高积累镉元素。建议在湘阴、长沙等地的Cd污染稻田进行覆膜栽培花生。

Cadmium concentration and translocation in paddy fields with different peanut varieties

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.