薇甘菊的化感作用研究

研究薇甘菊对萝卜、黑麦草、白三叶以及薇甘菊常见伴生树种马占相思、马尾松、大叶桉的生化他感作用。分别用薇甘菊地上部分、根部、枯枝叶和土壤的水提液以及地上部分的石油醚、乙酸乙酯和乙醇提取液按照一定浓度进行生物测定。研究表明，薇甘菊地上部分水提液能够显著影响受体植物生长，根水提液的抑制作用程度稍低，其枯枝叶水提液基本无作用。薇甘菊地上部分的石油醚和乙醇提取物均对受体植物幼苗生长表现出一定的抑制作用．但是乙酸乙酯提取物的作用最强烈，可使种子发芽过程受阻，幼苗生长受抑制程度高达90％以上．显示化感物质主要集中在这一部分。

Allelopathic potential of Mikania micrantha

The allelopathic potential of Mikania micrantha was investigated. The bioactivity of the aqueous extract (branches and leaves, roots, litters and soils), organic extracts ( branches and leaves) were evaluated on the growth of the following plants : radish ( Raphanus sativus ), rye grass ( Lolium multiforum) , white clover ( Trifolium repens L.). The results showed that the aqueous extract of the branches and leaves inhibited the growth of the receptor plants obviously, and the aqueous extract of the roots also influenced the growth of the plants but less significant. The litters had no obvious effect. The petroleum ether and ethanol extract inhibited the growth of the plants ,too. However, the ethyl acetate extract had much more impact. The ethyl acetate extract retarded the germination of the seeds, and the height of the plants decreased to 10%, which implied the existence of the allelochemicals.