Study On Antifungual And Herbicidal Constituents From Tuber Of Cyperus Rotundus L.

Cyperus rotundus L.is a kind of malignant weed in corn,sugarcane,vegetable and other crop fields.As the main reproductive organ,the tuber of C.rotundus is also a common Chinese herbal medicine with anti-inflammatory,anti-oxidation and anti-tumor effects.It is an important way for the research and development of new pesticides to find bioactive substances from plants and use them as lead compounds for biomimetic synthesis.In this paper,the antifungal and herbicidal activities of extracts from tubers of C.rotundus against plant pathogenic fungi and weeds were determined,and the active chemical components in the active extraction layer were separated and identified according to the activity tracking.The aim of this study was to find out the antifungal and herbicidal components in the tuber of C.rotundus,in order to provide the leading compounds for the research and development of new pesticides,and provide the basis for the comprehensive research and development of tuber resources of C.rotundus.The main results are as follows:1.The inhibitory effects of methanol extracts and different extracts from tuber of C.rotundus on 17 plant pathogenic fungi,including Fusarium graminearum Schwabe,Pyricularia grisea（Cooke）Sacc and Verticillium dahliae Kleb etc.,were determined by mycelial growth rate method.The results showed that methanol extract from tuber of C.rotundus was determined at the concentration of 10 mg/m L,the inhibition rate of Sclerotium rolfsii was up to 100%,and the inhibition rate of sevenplant pathogenic fungi were all above 70%,including F.graminearum,F.oxysporum f.sp.race 4,T.cucumeris,etc..At the concentration of 5 mg/m L,the antifungal activity of different extracts from tuber of C.rotundus against plant pathogenic fungi was petroleum ether extract,ethyl acetate extract,n-Butanol extract,aqueous phase,petroleum ether extract and ethyl acetate extract had good inhibitory effect on N.dimidiatum and S.rolfsii,the EC₅₀were 0.36 mg/m L,0.37mg/m L and 0.42 mg/m L,0.52 mg/m L,respectively.2.The effects of the tuber extracts of C.rotundus on the germination,root length,shoot length,plant height and fresh weight of the seeds of Eleusine indica L.,Bidens pilosa L.and Amaranthus spinosus L.were determined by means of culture dish and pot culture methods.The results showed that the methanol crude extract at the concentration of 10 mg/m L could completely inhibit the seed germination and root growth of A.spinosus,followed by the effect of E.indica.The effects of the tuber extracts of C.rotundus（5 mg/m L）on the germination,root length and shoot length of the three weeds,the order from strong to weak is as follows:petroleum ether extract,ethyl acetate extract,n-Butanol extract,aqueous phase;the effects of petroleum ether and ethyl acetate extracts on the germination,root length and shoot length of three weeds from large to small were A.spinosus,E.indica,Bidens pilosa,respectly,and the results of post-treatment showed that the petroleum ether extract had a good inhibitory effect on the plant height and fresh weight of A.spinosus and E.indica on 14 and 21 days,and the inhibition rate was above 94.45%.3.On the basis of biological activity tracking and chromatographic analysis,four compounds were isolated from the tuber of C.rotundus.Three compounds were identified as sugetiol triacetate,p-hydroxygenic acid and vanillic acid.4.The results of bioassay showed that:sugetiol triacetate（sesquiterpenoids）,p-hydroxycyanic acid（phenolic acid）and compound1（sesquiterpenoid）had no inhibitory effect on two plant pathogenic fungi at the concentration of 200μg/m L.The results of herbicidal activity showed that p-hydroxycyanic acid had a good inhibitory effect on the roo tgrowth of A.spinosus and its inhibition rate was 75.49%.