摘要
为探究土壤中重金属锌、镉单一及复合污染对番茄幼苗的胁迫响应,通过盆栽试验研究2种重金属胁迫土壤条件下番茄幼苗的生长状况。结果表明,单一及复合重金属胁迫下,番茄幼苗生物量、株高、叶绿素均随处理重金属质量比增大而降低,在低质量比锌与一定质量比镉的复合污染下植物生长量表现出拮抗作用。在高质量比重金属胁迫下,叶绿素a的下降速度明显大于叶绿素b,且重金属处理质量比与叶绿素a/b呈显著负相关。在单一及复合重金属胁迫时,番茄幼苗根中的丙二醇(MDA)质量比均随质量比上升有不同程度增加;在复合胁迫情况下,丙二醛(MDA)的质量比相较于空白对照组增长了7. 88%~125. 79%。过氧化物酶(POD)与超氧化物歧化酶(SOD)随胁迫质量比的增加呈现先增后减的变化趋势,这与低质量比锌镉复合产生拮抗作用的表现一致。通过相关性分析发现番茄幼苗对锌胁迫敏感部位从大到小为叶、根、茎,番茄幼苗对镉胁迫敏感部位从大到小为叶、茎、根,番茄幼苗对锌的耐性强于镉,通过联合毒性表征RI的计算发现,200 mg/kg锌与1 mg/kg、20 mg/kg镉的复合胁迫以及500 mg/kg锌与1mg/kg镉的复合胁迫下,联合毒性表现为拮抗作用,随施加质量比增加,锌与镉产生协同作用。
The present paper is inclined to present its pot experiment experience results on the growth of tomato seedlings to test the heavy metal stress on the tomato seedlings through single and combined stress. As a matter of fact,the tomato plants have been cultivated in a simulated greenhouse (at a temperature range between (25 ± 2) ° C) with 4 Zn contamination gradients (200 mg/kg,500 mg/kg,1 000 mg/kg,2 000 mg/kg) and 4 Cd contamination gradients (1 mg/kg,20 mg/kg,50 mg/kg,100 mg/kg). The young plants can be illuminated with a fullspectrum plant growth lamp (in a radiation range of (30 ± 5)W/m2) during a simulation period of 65 days. The results of our pot experiment reveal that the biomass,the plant height and the chlorophyll situation of the tomato seedlings tend to decrease with the increase of the treatment concentration rates regardless of the single or complex heavy metal stress. The combined pollution of the low concentration zinc and the specific concentration rate of cadmium suggest to have an antagonistic effect on the plant growth. On the other hand,under the high concentration influence of heavy metal stress,chlorophyll a/b also shows a tendency to decrease. The propylene glycol (MDA) content in the roots of tomato seedlings tends to increase with the growing concentration rates under the conditions of the single heavy metal stress or combined heavy metal stress. For instance,under the condition of the combined stress,the content of malondialdehyde (MDA)tends to increase by 7. 88%-125. 79% as compared with the blank control group. With the increase of the stress concentration,the peroxidase (POD) and superoxide dismutase (SOD)tend to show a trend of increase first and then decrease,which is consistent with the antagonism of the low concentration of zinc and cadmium. Through the correlation analysis,it has been found that tomato seedlings are sensitive to zinc stress in a descending order: leaves > roots > stems. Whereas the tomato seedlings prove to be sensitive to the cadmium stress in a descending order,as: leaves > stem > root,which indicates that tomato seedlings are more tolerant to zinc than to cadmium. Under the combined stress of 200 mg/kg zinc,1 mg/kg,20 mg/kg cadmium and 500 mg/kg zinc and 1 mg/kg cadmium,the combined toxicity indicates in an antagonistic effect,whereas the synergism between zinc and cadmium tends to increase with the increasing concentration rate. Nevertheless,with the increase of the applied concentration rate,zinc and cadmium tend to produce a synergistic effect.
作者
赵晓祥
冯璐
王宇晖
ZHAO Xiao-xiang;FENG Lu;WANG Yu-hui(School of Environmental Science and Engineering,Donghua University,Shanghai 201620,China)
出处
《安全与环境学报》
CAS
CSCD
北大核心
2020年第3期1176-1184,共9页
Journal of Safety and Environment
基金
上海市“科技行动创新计划”社会发展领域资助项目(17DZ1202204)。
关键词
环境学
锌胁迫
镉胁迫
锌镉复合胁迫
番茄幼苗
生理响应
联合毒性
environmentalology
zinc stress
cadmium stress
zinc-cadmium complex stress
tomato seedling
physiological response
joint toxicity
