Bioassay of allelopathic effects of three medicinal plants from rubiaceae family

In the present study,the allelopathic effects of water extracts of Paederia scandens(Lour.) Merr.,Hedyotis caudatifolia Merr.et Metcalf and Mussaenda pubescens L.on Raphanus sativus L.were tested by bioassay,and the mechanism of the allelopathy was also preliminarily explored by determining root activities,free proline contents of leaves and chlorophyll contents of acceptor.Results showed that different concentration of water extracts from donors had certain allelopathy on acceptor,and the allelopathy enhanced with the increase of extracts concentration.From the results,the order of allelopathic potential of donors was P.scandensH.caudatifoliaM.pubescens.It could be concluded that the allelopathy of water extracts of P.scandens posed certain inhibitory effects on acceptor with significantly reduced germination percentage,germination rate index,and chlorophyll content of acceptor,and increased free proline content of acceptor's leaves.