香草酸和香豆酸对莴苣幼苗生长的化感作用机理

Allelopathic effect mechanism of vanillic acid and coumalic acid on the growth of lettuce seedlings

【目的】明确化感物质的作用过程,帮助解决化感作用在农业生产中引起的连作障碍问题.【方法】以莴苣为活性受体,采用植物细胞和生理学方法,选择在农田土壤中广泛分布,影响多种作物生长的2种酚类化感物质香草酸和香豆酸,进行化感作用评价和化感作用机理研究.【结果】香草酸在0.1μmol/L时对根和茎促进作用分别达到了15.44%和37.24%,随着浓度的升高,逐步转化为抑制作用,在1 000μmol/L时的浓度下对根的抑制率达到了25.20%;香豆酸在低浓度下对莴苣幼苗的作用不明显,1 000μmol/L时对对莴苣根和茎的抑制率分别达到了46.6%和27.79%,具有明显的抑制效果.【结论】在高浓度酚酸的胁迫作用下,致使受体植物体内活性氧发生积累,导致MDA含量升高,细胞活力降低,最终影响莴苣的生长发育.

【Objective】In order to make clear the allelopathic mechanism,help to slove the continuous cropping barrier problem caused by allelochemicals.【Method】Using the lettuce as the receptor,the allelopathic effect of vanillic acid and coumalic acid widely distributed in farmland soil and affected the growth of the plant was assayed to study the allelopathic mechanism of vanillic acid and coumalic acid by plant cell and physiological methods.【Result】The lettuce treated by 0.1μmol/L vanillic acid concentrations improved the root and stem by 15.44%and 37.24%,respectively,and with increasing concentration of vanillic acid,the growth of seedlings was gradually inhibited.When concentration were 1 000μmol/L,the inhibition on the root was 25.20%.The effect of coumalic acid on the seedlings at low concentration was not obvious.At the concentration of 1 000μmol/L,the inhibition on the root and stem were 46.6%and 27.79%,respectively.【Conclusion】At the high concentrations,two allelochemicals could induce the accumulation of ROS causing the increase of MDA and decrease of the cell viability and inhibited the growth of lettuce seedlings.