水稻不同品种对镉吸收及分配的差异

Uptake and Distribution of Cadmium in Different Rice Cultivars

采用盆栽土培法,研究了镉在20个水稻品种体内的积累与分配。结果表明,水稻不同品种对镉的积累能力差异显著。土壤镉浓度为100mg·kg-1时,镉在水稻不同品种茎叶内的浓度变化范围为24.39～140.27mg·kg-1,积累量变化范围为1.54～14.35mg·盆-1;镉在水稻不同品种糙米内的浓度变化范围为0.87～2.70mg·kg-1,积累量变化范围为56.68～291.61μg·盆-1。不同水稻品种对镉的积累能力在抽穗前和抽穗后表现一致。水稻吸收的镉分配到籽粒中的比例非常低,糙米的平均镉浓度仅为水稻茎秆的1/30。糙米中的镉浓度与品种类型有关,即籼型>新株型>粳型。本研究还表明,糙米中的镉浓度和积累速率与水稻产量呈显著正相关,即高产伴随高镉。

Pot experiment was conducted to investigate accumulation and distribution of cadmium(Cd)using 20rice cultivars.The results showed that the rice cultiva rs tested differentiated in Cd accum ulation.Among the rice cultivars,Cd concentrations in straws varied from 24.39mg ·kg -1 to 140.27mg ·kg -1 ,while Cd concentrations in brown rice were in a range of 0.87～2.70mg ·kg -1 ,when Cd concentration in the soil wa s fortified at 100mg ·kg -1 .The abilities of the rice cultivars in Cd accumulation remained consistent during the period of befo re and after tassel.It has been indic ated that only a very small proportio n of Cd absorbed by rice plant was transported to brown rice,Cd concentration in brown rice was on ly 1/30of that in stem averagely.Cd c oncentrations also varied among rice genotypes,and the sequence was in an order:indica>new plant type>japonica.The Cd concent rations and accumulation speed in brown rice both correlated significantly with gra in yields among the rice cultivars.