凹土复配剂修复辣椒自毒作用的响应面优化及其机理研究

Optimization of attapulgite-based agent by response surface methodology and remediation mechanisms on autotoxicity of pepper

以邻苯二甲酸二丁酯(DBP)模拟辣椒连作自毒物质,选择凹土、牛粪、腐植酸为修复剂,采用BoxBehnken试验设计优化了复配参数,探讨了复配剂对辣椒DBP自毒作用的修复机理。结果显示,对DBP修复效果最好的复配剂为凹土20 g/kg+牛粪70 g/kg+腐植酸617 mg/kg,在此条件下,辣椒株高实测值与模型预测值相符。复配剂能显著增强辣椒根际土壤的脲酶、脱氢酶、蛋白酶和蔗糖酶活力,使辣椒根系受DBP毒害减轻,根系过氧化物酶(POD)和过氧化氢酶(CAT)活力增强,膜脂过氧化程度减弱,丙二醛(MDA)含量降低,根系活力提高。凹土复配剂对辣椒连作中DBP自毒作用有良好的修复作用。

In this study,Di-n-butyl phthalate ester（ DBP） was applied to simulate the autotoxins from chili continuous cropping soil,attapulgite clay,cow dung and humic acid were chosen as the repair agents,the Box-Behnken experimental design was used for parameters optimization of restoration agent,and the repair mechanism of the restoration agent to autotoxicity of DBP was explored. Results showed that the best effect on DBP repair was the agent mixed with attapulgite clay 20 g / kg,cow dung 70 g / kg,and humic acid 617 mg / kg. With this agant,the pepper plant height was 41. 36 cm,which was consistent with predicted values. With the agent application,the activities of capsicum rhizosphere urease,dehydrogenase,protease and sucrose enzyme were significantly enhanced,the autotoxicity of DBP to capsicum root was alleviated,which expressed in peroxidase（ POD） and catalase（ CAT） activity of root were enhanced,membrane lipid peroxidation was weakened,malondialdehyde（ MDA） content was reduced,and root activity was increased. It was concluded that attapulgite-based agent had a good remediation effects on autotoxicity of DBP in chili continuous cropping soil.