重茬大豆根系分泌物的成分及化感作用研究

Research on the Composition in the Exudate from Root System of Continuous Cropping Soybean and Its Allelopathy

[目的]鉴定重茬大豆根系分泌物的成分并研究其化感作用。[方法]采用GC-MS分析法鉴定重茬大豆根系分泌物成分。模拟大豆自毒作用,较系统地研究不同浓度水平下重茬大豆根系分泌物对大豆生长的形态指标、细胞膜结构与功能、保护性酶活性等自毒作用的生理生化机制。[结果]重茬大豆根系分泌物成分主要包括烃、有机酸、醇、酯、酮、酚、醛、苯、噻唑、酰胺等物质。重茬大豆根系分泌物对供试大豆叶绿素的含量表现出低浓度促进、高浓度抑制作用;对大豆种子的萌发和发芽速度有明显的抑制作用,随着浓度的增大抑制作用增强。供试大豆SOD、POD总活性及MDA含量随着大豆根系分泌物浓度的增大均表现为持续升高趋势,化感作用达到极显著水平。[结论]为缓解乃至于消除连作障碍提供了理论依据。

[Objective] The composition in the exudates from continuous cropping soybean root was identified and its allelopathy was studied.[Method] The component in the exudate of soybean root was identified with the method of GC-MS analysis.The physiological and biochemical mechanism including the morphological index,the cell membrane structure and its function,the activity of the protective enzymes etc in the soybean growth under the different concentrations of root exudates with itself toxic effect,which was simulated,was more systematically studied.[Results] cropping The components of the exudates from soybean root mainly included hydrocarbon,organic acid,alcohol,ester,ketone,phenol,formaldehyde,benzene,thiazole,amide and others.These components showed the promotion to content of chlorophyll in tested soybean while it was with low concentration and the inhibition,with high concentration.These components had the obvious inhibition to the soybean seed germination and its germination rate and the inhibition was strengthened with the concentration-increasing.The trend of the activity of SOD and POD,the content of MDA in tested soybean was continually rising with the concentration-increasing of exudates from soybean root and the allelopathic reached the significant level.[Conclusion] The theoretical basis for alleviation and even elimination of the barrier of repeated tillage was provided.