カドミウム汚染土壌で栽培したダイコン2品種の生育初期における地上部と根部のカドミウム，亜鉛，マンガンおよび銅の濃度

摘要

A pot culture experiment was conducted to investigate the cadmium, zinc, manganese and copper concentrations of two Japanese radish cultivars (Raphanus sativus L. cv. Harunomegumi and Raphanus sativus L. cv. Akibutai) grown for 9 weeks in soil whose respective cadmium and zinc concentrations were 3.3 and 68 mg/kg of dried soil. Both of the Japanese radish cultivars grew normally throughout the growth period, the weight of the shoots being 2.8 times that of the roots. The cadmium concentrations in the shoots of both cultivars initially increased for 6 weeks after sowing and then slowed. The cadmium concentrations in the shoots after 9 weeks of growth were respectively 2.4 and 1.5 mg/kg for Harunomegumi and Akibutai, this 0.9 mg/kg difference indicating cultivar dependence. The cadmium concentrations in the roots of both cultivars were about one fourth of those of the shoots. The zinc, manganese and copper concentrations varied similarly for both of the cultivars. The zinc concentrations in the shoots did not fluctuate greatly at between 20 and 50 mg/kg, this being similar to the zinc concentrations in the roots throughout the growth period. The manganese concentrations in the shoots increased from around 2 to 12 mg/kg during the growth period, while those in the roots remained almost constant at around 1.5 mg/kg. The copper concentrations in the shoots tended to be higher than those in the roots throughout the growth period. The copper concentration in the shoots after 9 weeks of growth was around 1.2 mg/kg, being 1.4 times that in the roots.%ダイコンのカドミウム，亜鉛，マンガンおよび銅吸収をrn調査するために，2品種「春のめぐみ」と「秋舞台」につrnいてカドミウムと亜鉛を，それぞれ3.26と67.9mg/kg（乾rn土重量当たり）含む土壌で9週間ポット栽培した．rnいずれのダイコンも生育に異常な兆候はみられず，地上rn部が根部より生育量が大きかった．9週目での「春のめぐrnみ」の生育量は「秋舞台」の2.8倍であった．