Studies Of Phytolacca Americana Allelopathy On Several Common Weeds In The Seedling Stage

In order to understand the allelopathic effect of Phytolacca on common weeds,the bioassay method of germination box and pot experiment was used to study the Allelopathy of different concentrations of extracts and root exudates from different parts of Phytolacca on several common weeds;meanwhile,the organic compounds from different parts of Phytolacca were separated by extraction and the allelopathic effects of each extract on weeds were determined.The main results of the study are as follows:Altair,Eclipta prostrata sarson and feather cockscomb were as the receptor plant in Phytolacca's root and stem and leaf water extracts of bioassay.The results showed that in the range of the tested concentration,the aqueous extracts of different parts had a certain inhibitory effect on the chlorophyll content,protective enzyme catalase and superoxide dismutase activity of four kinds of weeds,and promoted the activity of peroxidase and the content of malondialdehyde,it shows that Phytolacca have an obvious allelopathic effect.The inhibition effect on the germination rate,root length and chlorophyll content of the Altair increased with the concentration of the extract,and the effect on its CAT activity was high concentration inhibition and low concentration promotion,and the root length and CAT activity of the Eclipta prostrata had high concentration inhibition and low concentration promotion effect.Among them,the root extracts from Phytolacca americana had the most significant inhibitory effect on weeds,followed by leaf extract.20 mg/mL root extract had the most significant inhibitory effect on four weeds.Inhibitory effects of extracts from four kinds of weeds increased with its concentration,the most significant inhibitory effect on Altair and Eclipta prostrata.The extraction method was used to separate the allelochemicals from the roots,stems and leaves of Phytolacca.The roots,stems and leaves of Phytolacca were extracted by ethanol,the ethanol was evaporated by Rotaryevaporator,then dissolved in distilled water,and then extracted with petroleum ether,ethyl acetate and n-butanol in turn,finally,the effects of each extraction on the germination and the growth of Altair,Eclipta prostrata Sarson and Feather cockscomb were determined.The results showed that,in the range of test concentration,each extraction had different inhibitory effects on the growth of weeds,the most significant inhibitory effect on Altair and Eclipta prostrata.Among them,the inhibition effect of crude extracts from different parts on four weeds is in the order of root > leaf > stem,the inhibition effect of petroleum ether components on weeds is the strongest,and the higher the concentration is,the more significant the inhibition is,followed by the ethyl acetate phase.The effect of Phytolacca's root exudates of Altair,Eclipta prostrata,Sarson and Feather cockscomb on seed Germination and seedling growth was tested by pot experiment.The results showed that the root exudates of Phytolacca could inhibit the germination and the seedlings growth of the four weeds tested,the inhibition of catalase and superoxide dismutase was the most significant.In the four receptor plants,the inhibitory effect of the root exudates of the Phytolacca on the Eclipta prostrata and Feather cockscomb was the most significant.