有机肥对镉胁迫下不同基因型水稻镉吸收和分配的影响

Effects of Organic Manure on Uptake and Distribution of Cadmium in Different Rice Genotypes Under Cadmium Stress

以镇稻88和Ⅱ优107两个不同基因型水稻为材料,采用两年盆栽试验方法,研究了有机肥对水稻镉吸收及分配的影响。结果显示:镉胁迫(3.0mg·kg-1)下,水稻各器官的镉含量以及根系镉分配比例增加,穗的镉分配比例减少。有机肥对不加镉处理(土壤背景镉含量0.202mg·kg-1)的营养器官镉含量没有显著影响,籽粒镉含量略降低,但影响不显著。有机肥降低加镉处理的根系、糠层和精米的镉含量,影响根系的镉分配比例,减少穗的镉分配比例,并且一定程度减少籽粒中精米的镉分配比例。有机肥可能是通过减少土壤有效态镉,以降低水稻植株对土壤中镉的吸收,并且抑制镉往地上部以及精米中输送,从而显著降低了精米中的镉含量。另外,有机肥对两个基因型水稻的影响表现不同。

Two rice genotypes,Zhendao88（Oryza sativa subsp.japonica） and Eryou107（O.sativa subsp.indica）,were used to study the effects of organic manure（OM） on the uptake and distribution of cadmium（Cd） in rice by two years pot experiments with two-factor random block design.Two Cd treatments were natural soil（background concentrations of soil cadmium 0.202 mg·kg-1） and artificial Cd-contaminated soil（added 3.0 mg·kg-1 cadmium）.Two fertilizer treatments were chemical fertilizer（300 kg N·hm-2） and chemical fertilizer（300 kg N·hm-2）＋OM（1.96 g·kg-1 dried soil）.The results showed that Cd concentration in various organs of plant and distribution ratio of cadmium in root increased significantly under cadmium stress（3.0 mg·kg-1）,while the distribution ratio of cadmium in panicle decreased.OM had no significant effects on Cd concentration in vegetative organs of the treatments with natural soil,and slightly decreased that in panicle.However,OM could reduce the Cd concentration in root,bran and milled rice,increase the distribution ratio of cadmium in root,and decrease that in panicle under cadmium stress.For panicle,the distribution ratio of cadmium in milled rice was also partially decreased with OM treatment under cadmium stress.Therefore it is suggested that OM might significantly decrease the Cd concentration in milled rice by reducing available Cd in the soil and inhibiting Cd transportation from root to above-ground and above-ground to milled rice.Furthermore,the effects of organic manure in two different rice genotypes were different.