The Study On Allelopathy And Chemical Control Of Alien Plant Of Solidago Canadensis

In this paper,the Canada Goldenrod(Solidago canadensis L.),a kind of alien invasive weed in China,was chosen as a research object.The germination and chemical control of the seed and rhizome of Solidago canadensis was studied.This study may provide theoretical foundation for validation control the Solidago canadensis spread in our country. By petri dish and pot experiments,allelopathy of different concentration of aqueous extracts from Solidago canadensis on the seed germination and seedling growth of crops and weeds including Triticum aestivum,Glycine max,Zea mays,Gossypium hirsutum and Echinochloa colonum,Leptochloa chinensis,Capsella bursa-pastoris,Beckmannia syzigachne,Sclerochloa kengiana,Setaria faberii,Alopecurus aequalis,Digitaria ciliaris, Alopecurus japonicus,Eclipta prostrata,Amaranthus retroflexus,Vicia sativa,Setaria viridis,Galium aparine var.tenerum and Poa annua were studied,which may reveal the effects of Solidago canadensis to agriculture production and ecosystem,and supplement and complete the allelopathic data of Solidago canadensis to the main crops and weeds in our country,and establish the allelopathic spectrum of Solidago canadensis based on the above research.The allelochemicals of Solidago canadensis were extracted,isolated and identified,which may explain the invasion and vicious mechanism of Solidago canadensis.The results of germination and chemical control of the seed and rhizome of Solidago canadensis revealed that the seed germination rate reached to 55%,while it increased obviously after store in the room for two months and reached to 80%.The germination rate of rhizome of Solidago canadensis was between 47.6%and 80%when it was buried for three months at the natural condition.When the rhizome was put in room and at 5℃for a month respectively,the germination rates of the rhizome were 50%and 16.7%.When the rhizome was placed in outdoor and at -25℃for a month respectively,both of them couldn't germination.It was found that fluroxypyr,mixture of fluroxypyr and lactofen,glyphosate·synergist had good preventive effects on Solidago canadensis.The synergy of glyphosate add 8%synergist c was best.The method of linking identical-effects-line to filter the optimal proportion of fluroxypyr and lactofen was 1:1.05.By petri dish and pot experiments,the results of allelopathy of different concentration of aqueous extracts from Solidago canadensis to four crops and fifteen weeds showed that the seed germination of Glycine max,Echinochloa colonum,Sclerochloa kengiana and Eclipta prostrata were not significantly affected by the aqueous extracts,while that of Vicia sativa was promoted.And the seed germination of Beckmannia syzigachne was completely inhibited at 0.1 g·mL^-1.For seedling growth,the restrained influences of root length were stronger than those of shoot length,while the inhibitory effects of aqueous extracts from Solidago canadensis on fresh weight were strongest and the effects of fresh weight of the aerial part on weeds were stronger than those of crops except Vicia sativa in the test of plant growth.Eighteen compounds as seven main types of terpene,ketone,alcohol,ester,acid, aldehyde and steroid were identified from petroleum ether extraction of Solidago canadensis by Gas Chromatography Mass Spectrometer(GC-MS).The main substances of these compounds were Phytol,Hexadecanoic acid and Stigmasta-7,25-dien-3-ol,(3β,5α)-. Two allelochemicals were isolated and identified from ethyl acetate extraction of Solidago canadensis by used silica gel column chromatography,High Performance Liquid Chromatography(HPLC),Liquid Chromatography Mass Spectrometer(Le-MS),GC-MS and ¹H-Nuclear Magnetic Resonance(¹H-NMR),and they were Hexadecanoic acid and Kaempferol-3-O-β-D-Glucopranoside which belonged to flavonoid.