藿香不同部位浸提液对其种子萌发及幼苗生长的化感作用

Allelopathy effect of aqueous extracts from different parts of Agastache rugosa on its seed germination and seedling growth

[目的]研究藿香不同部位水浸提液对其种子萌发及幼苗生长的化感作用,为分析连作障碍提供理论依据。[方法]以化感作用较明显的藿香为材料,采用水浸提液来模拟自然条件下雨雾淋溶的化感作用方式,以霍香叶、茎、根各部位不同质量浓度(0、0.012 5、0.025 0、0.050 0、0.100 0 g·m L^(-1))水浸提液处理藿香种子及幼苗,检测其相关生理生化指标的变化。[结果]霍香叶、茎、根各部位不同质量浓度水浸提液处理降低了藿香幼苗根系活力、叶绿素含量及可溶性蛋白含量,抑制了超氧化物歧化酶(SOD)、过氧化物酶(POD)和过氧化氢酶(CAT)活性,提高了幼苗叶片相对电导率与丙二醛(MDA)含量。不同部位水浸提液均能抑制藿香种子萌发及幼苗生长,表现出显著的浓度梯度效应和部位差异,水浸提液浓度越高,抑制作用越强,其中同一部位以质量浓度0.100 0 g·m L^(-1)的水浸提液处理抑制作用最强,不同部位相同浓度处理以叶的水浸提液处理对幼苗的抑制作用最强,且均达到了显著水平。[结论]藿香水浸提液处理对其种子萌发及幼苗生长具有抑制作用,表现出一定的化感自毒作用,生产中应采取必要的耕作措施避免连作障碍。藿香不同部位水浸提液对其幼苗的化感作用由强到弱表现为叶、根、茎。

[Objectives]This paper aimed at studying the allelopathy of aqueous extracts from different parts of Agastache rugosa on its seed germination and seedling growth which was expected to provide theoretical basis for the continuous cropping obstacle.[Methods]Using A. rugosa which had obvious allelopathy as materias,simulating natural rain fog leaching allelopathy and using the aqueous extracts of different concentrations（ 0,0. 012 5,0. 025 0,0. 050 0,0. 100 0 g·m L^-1） from different parts to deal with the A. rugosa seeds and seedlings,we detected the changes of its related physiological and biochemical indexes. [Results]The treatments dealt with different concentrations of aqueous extracts from different parts decreased the root activity,chlorophyll and soluble protein contents of A. rugosa seedling,inhibited its superoxide dismutase（ SOD） and peroidase（ POD） activities and increased its seedling leaf conductivity and MDA contents. The aqueous extracts from different parts could all inhibit A. rugosa seed germination and seedling growth,which showed obvious concentration gradient effect and part difference. The inhibitory effect enhanced with the increase of the concentration and the mass concentration of 0.100 0 g·m L^-1had the strongest inhibitory effect on the same part. Among the treatments from different parts dealt with the same concentration,the aqueous extracts from leaf showed the strongest inhibitory effect on seedling,and reached a very significant level. [Conclusions]The treatments dealt with the aqueous extracts from different parts of A. rugosa had inhibitory effect on its seed germination and seedling growth and showed a certain sense of self toxicity. Necessary farming measures should be taken to avoid continuous cropping obstacles. In general,the allelopathy order of aqueous extracts from different parts of A. rugosa was leaf,root and stem.