玉米生长苗期与穗期对土壤外源镉的响应  

Responses of Maize during the Seedling and Heading Stage to Cadmium Availability in Soil

作　　者：祁剑英 杜天庆[1] 郝建平[1] 薛建福[1] 杨珍平[1] 崔振魁[1] 陈梦妮[1] 

机构地区：[1]山西农业大学农学院,山西太谷030801

出　　处：《山西农业科学》2016年第11期1627-1632,共6页Journal of Shanxi Agricultural Sciences

基　　金：山西省自然科学基金项目(2014011031-1)

摘　　要：采用盆栽试验,研究了不同质量分数的镉胁迫对大丰30玉米苗期与穗期细胞膜透性、丙二醛含量、过氧化物酶活性、叶片枯黄比例以及干物质量的影响,并分析了大丰30玉米生长苗期与穗期对镉胁迫的抗性差异。结果表明,土壤外源镉对玉米生长的抑制作用主要发生在穗期（50~70 d）,并在中后期（70~90 d）有所减弱;在玉米生长穗期,当外源镉为1 mg/kg时,过氧化物酶（POD）活性显著低于对照（P〈0.05）,而其他指标没有显著变化,对玉米造成影响的土壤外源镉临界值小于1 mg/kg;外源镉质量分数与丙二醛（MDA）含量和细胞膜透性均呈二次曲线回归模型,但高质量分数镉胁迫下细胞膜透性变化量大于MDA含量;苗期7 mg/kg外源镉胁迫下叶片的枯黄比例是对照的3.1倍,且显著高于对照（P〈0.05）。研究结果可为进一步了解镉胁迫对玉米不同生育时期的影响机制以及丰富玉米重金属污染胁迫研究提供理论依据。To investigate the effects of cadmium availability in soil on maize Dafeng 30 and to analyse the difference of resistance between seeding stage and heading stage, the pot experiment was conducted to study cell membrane permeability, malondialdehyde （MDA） content, peroxidase （POD） activity and dry matter in seeding stage and heading stage of maize. The results showed that the inhibition rate of cadmium availability on maize growth was the highest in the heading stage （50-70 days after sowing）, while was lower in the late （70-90 days after sowing）. During the heading stage, the POD activity under 1 mg/kg of cadmium availability was significant lower than that under the control （0 mg/kg）（P 〈 0.05 ）, with no significant differences on other indicators. The threshold of the effect of cadmium availability on maize was below 1 mg/kg. A quadratic model was observed between the cadmium availability concentration and the MDA content, cell membrane permeability, which showed that the variation of cell membrane permeability was more than MDA content under higher cadmium concentration. In addition, the proportion of litter with 7 mg/kg of cadmium availability was 3.1 times greater than the control during the seedling stage（P 〈 0.05 ）. The results could provide a further understand of the mechanism of different growth stage under Cd stress, and some theory to enrich the study on the responses of maize under cadmium stress.

关 键 词：外源镉 玉米 生理响应 生育时期 

分 类 号：S513[农业科学—作物学]