Allelopathy of aqueous extracts when intercropping in poplar rhizosphere soil
-
摘要: 杨树Populus长期连作产生土壤恶化和土地生产力逐代降低的现象。以江苏省徐州丰县大沙河林场杨树多代连作人工林为研究对象,不同连栽代次的杨树根际土壤水浸提液稀释成不同质量浓度(100,150,200,500,800,1 000 gL-1)后处理莴苣Lactuca sativa,小麦Triticum aestivum,玉米Zea mays等的种子及幼苗,重复3次处理-1,探索杨树连栽其根系分泌物中化感物质活性,以期为农林复合系统的合理构建及优化提供一定依据。结果表明:杨树根际土壤水浸提液质量浓度较低时,对莴苣及小麦种子萌发及幼苗生长具促进作用,质量浓度增加,促进作用减弱,超过临界质量浓度,转为抑制作用,且随质量浓度的增高而加强;而本研究采用的各质量浓度浸提液对玉米始终表现为抑制作用。从杨树连栽代次上看,在临界质量浓度以上萌发率随连栽代次增加而减小,芽、根长也逐代减短,在临界质量浓度以下反之;总体上,浸提液对3种农作物种子芽及根的负化感效应逐代增强,抑制作用逐渐增大。综合化感效应指数表现出随着杨树连栽代次的增加而化感作用有增强的趋势,最高与最低综合化感隶属函数值间相差3.384 3~3.808 8。图1表3参30Abstract: To explore the allelochemical activity of poplar root exudates and to provide a basis for constructing reasonable agroforestry systems, aqueous extracts of different successive poplar rhizosphere soils were diluted to different concentrations(100, 150, 200, 500, 800, 1 000 gL-1) for application on seeds and seedlings of lettuce, wheat, and corn with three replication every treatment. The study was conducted on continuous cropping in a poplar plantation in Da Shahe Forest Farm in Fengxian County, Xuzhou City, Jiangsu Province. Results showed that when the aqueous extract of polar rhizosphere soil was at a low concentration, lettuce and wheat seed germination and seedling growth were promoted. With increasing concentration promotion decreased, and when a critical concentration was exceeded growth was inhibited. The inhibition further increased with increasing concentrations. For corn seed germination and seedlings the aqueous extract always inhibited growth. Above the critical concentration, germination rates gradually decreased with succeeding generations as did shoot and root length; whereas below the critical concentration they gradually increased. For both lettuce shoots and lettuce roots, negative allelopathic effects gradually increased with each generation. Comprehensive allelopathic effects of poplar root exudates on crop growth increased with each generation. The difference values between the highest and the lowest comprehensive allelopathic effect was 3.384 3-3.808 8. [Ch, 2 fig. 3 tab. 30 ref.]
-
Key words:
- agoforestry ecosystem /
- poplar /
- continuous cropping /
- rhizosphere /
- aqueous extract /
- allelopathic effect
-
链接本文:
https://zlxb.zafu.edu.cn/article/doi/10.11833/j.issn.2095-0756.2015.02.014
计量
- 文章访问数: 2198
- HTML全文浏览量: 337
- PDF下载量: 458
- 被引次数: 0