South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China. E. Mail: zhaohb04@mails.gucas.ac.cn, lsspsl@mail.sysu.edu.cn.
*Correspondence author.
1Institute of Ecology and Evolution, State Key Lab of Biocontrol, Sun Yat-sen University, Guangzhou, 510275, China.
In laboratory and green house investigations, we studied the allelopathic effects of soil beneath the Mikania micrantha H.B.K on germination and seedling growth of tomato (Lycopersicon esculentum Mill.), cabbage (Brassica chinensis L.) and ryegrass (Lolium multiforum Lam.). In laboratory studies, the extracts of soil beneath M. micrantha decreased the shoot length of tomato, but not of cabbage and ryegrass. However in greenhouse, the soil beneath M. micrantha reduced root elongation of cabbage but stimulated the root elongation of ryegrass. Besides there was no reduction in Cabbage roots growth in the same soil supplemented with activated charcoal. The soil beneath M. micrantha and its extracts were moderately allelopathic. The M. micrantha allelochemicals released into soil did not reach phytotoxic concentrations. These results indicate that allelopathy is not the main mechanism for the invasive success of M. micrantha.
Activated charcoal, Brassica chinensis L., cabbage, Lolium multiforum Lam., Lycopersicon esculentum Mill. Mikania micrantha, natural soil, ryegrass, tomato
