不同间隔年限地黄土壤的自毒作用和酚酸类物质含量

Autotoxicity and phenolic acids content in soils with different planting interval years of Rehmannia glutinosa.

分别取2、4、6、8年前种植过地黄的土壤进行大田再植生物测试,并采用HPLC检测再植地黄土壤中与化感现象密切相关的5种酚酸(阿魏酸、对羟基苯甲酸、香草酸、香豆酸和丁香酸)的含量。结果表明:随着土壤间隔年限的增加,大田再植地黄的块根干质量、体积和叶片干质量依次增加,且从地黄苗期就开始表现出这种变化趋势;地黄土壤中5种酚酸的含量也依次降低,间隔2、4、6、8年的再植地黄土壤中5种一元酚酸总含量分别为1.503、1.323、0.700和0.340μg.g-1。间隔2、4、6、8年的再植地黄土壤水提液中阿魏酸、对羟基苯甲酸和香豆酸含量与地黄大田生物测试结果呈显著或极显著负相关。从整体看,地黄生育的前期和中期应当是地黄化感作用的重点时期。

Field replanting bioassay was conducted on the soils having planted with Rehmannia glutinosa for 2, 4, 6, and 8 years. The soils were replanted with R. glutinosa, and 5 phenolic acids （coumalic acid, 4-hydroxybenzoic acid, venillic acid, syringic acid and ferulic acid） closed related to allelopathetic effects in the replanted soils were analyzed by using high pressure liquid chromatography （HPLC）. The results showed that on the soils with increasing planting interval years of R. glutinosa, the root tube dry mass and volume and the leaf dry mass of replanted R. glutinosa increased since seeding stage then, while the contents of test five phenolic acids in the replanted soils decreased accordingly. The total contents of test five monohydric phenolic acids in the replanted soils having been planted with R. glutinosa for 2, 4, 6, and 8 years was 1. 503, 1. 323, 0. 700, and 0. 340 ug·g^-1, respectively, and the content of ferulic acid, 4- hydroxybenzoic acid, and coumalic acid in soil water extract had significant negative correlation with filed planting bioassay results. As a whole, the early and middle growth stages of R. glutinosa should be the crucial periods for the allelopathetic effects of R. glutinous.