Cr和As及其交互作用对黑麦生长的毒性效应

Toxic effects of Cr-As and their interaction on the growth of rye

研究土壤中Cr、As及其复合污染对植物生长发育的影响及毒性效应具有十分重要的理论意义。通过黑麦(Lolium perenne)盆栽试验,研究了Cr、As及其交互作用对黑麦出苗率、不同生长时期的株高及茎叶鲜质量的毒性效应,从而为检测土壤的污染程度,从生态学角度衡量土壤质量健康状况提供科学依据。结果表明:(1)单元素As对黑麦出苗率无影响,对株高有刺激作用。随着Cr质量分数的增大,出苗率和株高均下降,表现为毒害作用;交互处理中,Cr的加入掩盖了As的刺激作用而表现出对黑麦出苗率和株高的毒害作用。不同As水平下,黑麦出苗率和株高主要受Cr处理质量分数的影响。(2)随着单元素As质量分数增大,茎叶鲜质量有所下降,但各处理均大于对照。随着单元素Cr处理质量分数增大,茎叶鲜质量都较对照逐渐降低,但小于20mg·kg-1的Cr处理较对照增加;交互处理中,同一Cr水平下,黑麦茎叶鲜质量随As质量分数的增大略有所降低,但随着Cr水平的增大抑制作用加强。同一As处理水平下,茎叶鲜质量随Cr质量分数的增大逐渐减低。(3)Cr、As交互作用对黑麦出苗率、株高、茎叶鲜质量产生的毒性效应表明Cr的影响比As大。

It is of great theoretical significance to research Cr-As and their interaction in soil on plant growth and development and toxic effects. Pot experiments are done to study toxic effects of Cr and As, as well as their interaction, on the seedling rate of rye （Lolium perenne）, the average height of plant and the wet weight. The results provide a scientific basis for detecting pollution grade of soil and scaling soil health conditions from the angle of ecology views. The results are showed that： 1） As has no influence on the seedling rate, but has stimulating effect on the average height. With the increasing of Cr concentration, the seedling rate and plant height drop down, which shows toxic effects. In interaction treatments, the adding of Cr conceals the stimulating effects of As, but shows the toxicity to the seedling rate and plant height. The seedling rate and the plant height, on different As treatment levels, mainly are influenced by Cr concentration. 2） With the increasing of As concentration, the wet weight of rye drops, but the plant wet weights of all treatments are greater than control. With the increasing of Cr concentration, the wet weights of rye plants decrease in contrast with control, but increase when Cr concentration is less than 20 mg·kg^-1. In interaction treatments, on the same Cr treatment level, the rye＇s wet weight decreases with the increasing of As concentration, but toxic effect of Cr is strengthened with the Cr treatment level increasing. On the same As level, the wet weight decreases gradually with the increasing of Cr concentration. 3） The toxic effects of Cr and As and their interaction on the seedling rate, plant average height and wet weight of rye show that the effect of Cr is more important than As.