重茬地黄土壤酚酸的动态积累及其对地黄生长的影响

Phenolic compounds accumulation in continuously cropped Rehmannia glutinosa soil and their effects on R.glutinosa growth.

为了探究酚酸物质与地黄连作障碍之间的关系,检测了重茬地黄土壤中阿魏酸、香草酸、香草醛和对羟基苯甲酸等4种酚酸物质的积累量,并通过水培条件下添加酚酸,研究了4种酚酸对地黄生长的影响。结果表明:阿魏酸、香草酸和香草醛含量在地黄生长期表现为持续增加,而对羟基苯甲酸含量先升高后降低;外加阿魏酸(8μg.ml-1)、香草酸(0.8μg.ml-1)、香草醛(1.2μg.ml-1)和对羟基苯甲酸(3.0μg.ml-1)对水培地黄根长、根质量、全株鲜质量和株高有较强的抑制作用;酚酸处理使地黄叶片叶绿素含量降低,除对羟基苯甲酸外差异性极显著;经过酚酸处理的地黄幼苗SOD和POD活性为先升高后下降,丙二醛含量升高,其中阿魏酸的处理使根中酶活性降至最低,根部腐烂死亡。推测4种酚酸可能是造成地黄化感作用的物质。

To clarify the relationships between phenolic compounds and continuous cropping obstacle of Rehmannia glutinosa, the accumulation amounts of ferulic acid, vanillic acid, vanillin, and β-hydroxybenzoic acid in continuously cropped R. glutinosa soil were measured, and the effects of these four phenolic acids on R. glutinosa growth were studied with water culture. The results showed that in the growth period of R. glutinosa, soil ferulic acid, vanillic acid, and vanillin contents had a persistent increase, while β-hydroxybenzoic acid content increased first but decreased then. The addition of ferulic acid （8 μg·ml^-1 ）, vanillic acid （0. 8 μg·ml^-1 ）, vanillin （ 1.2 μg·ml^-1 ）, and β-hydroxybenzoic acid （ 3.0 μg·ml^-1） in water culture had stronger inhibitory effects on R. ghainosa root length, root mass, fresh plant mass, and plant height. Treating with test phenolic acids except β-hydroxybenzoic acid increased leaf chlorophyll content significantly, compared with the control. After treated with test phenolic acids, plant SOD and POD activities decreased after an initial increase, and plant malondialdehyde （MDA） content increased. In the treatment of ferulic acid, root SOD and POD activities were the lowest, and roots were rotted and dead. It was suggested that the test four phenolic acids might be the allelomechemicals of R. glutinosa.