4种杂草浸提液对柳枝稷种子萌发的化感作用研究

采用室内生物测定法,研究不同浓度梯度下白草(Pennisetum flaccidum)、赖草(Leymus secalinus)、硬质早熟禾(Poa sphondylodes)和猪毛蒿(Artemisia scoparia)地上部分和根系浸提液对柳枝稷(Panicum virgatum)种子萌发的化感作用,以期为揭示柳枝稷与本土杂草之间的相互作用机制提供借鉴意义.结果表明:不同浓度的白草、赖草和硬质早熟禾浸提液处理均抑制了柳枝稷的种子萌发和幼苗生长,尤其是对发芽指数、胚芽长度和幼苗生物量的影响较大.同时,地上部分浸提液的抑制作用强于根系.在0.1 g/mL白草、赖草和硬质早熟禾地上部分浸提液处理下,柳枝稷胚芽长分别降低了81.13％、86.42％和90.19％.猪毛蒿浸提液在低浓度下抑制作用较小,甚至提高柳枝稷胚根和胚芽长度,表明其浸提液中某些化感物质起到促进作用.4种杂草浸提液在0.1 g/mL浓度下的综合化感效应值分别高达-5.89,-6.17,-5.17和-6.15.综上所述,不同杂草对柳枝稷的影响存在明显差异,生产实践中要根据不同物种和密度采取相应防治措施,以保证柳枝稷良好生长.

Study on Allelopathy Effect of Four Different Weed Extract on Seed Germination of Switchgrass (Panicum virgatum)

Experimental bioassay method was adopted to measure allelopathy effects of extract at different concentrations from aerial part and root of Pennisetum flaccidum,Leymus secalinus,Poa sphondylodes and Artemisia scoparia to seed germination and seedling growth of switchgrass (Panicum virgatum).The study will provide significant reference to reveal the interaction mechanism between switchgrass and native weeds in the process of cultivation.The results showed that Pennisetum flaccidum,Leymus secalinus and Poa sphondylodes extract at different concentrations suppressed germination and seedling growth of swicthgrass,especially for the germination index,coleoptile length and seedling biomass per plant.Their inhibition effects effect of the aerial part was stronger than that of the root.Under the treatment of 0.1 g/mL aerial part extract of the three kinds of weed,the coleoptile length of switchgrass was reduced by 81.13 ％,86.42 ％ and 81.13 ％ respectively.However,A.scoparia extract showed small inhibition effect at low concentration,and even increased the radicle and coleoptile length of switchgrass,which indicated some promote allelochemicals in the extract.The synthetical effects of the above four kinds of weed extract at the concentration of 0.1 g/mL were-5.89,-6.17,-5.17 and-6.15.To conclude,there were differences among species and concentrations in the allelopathy of associated weeds to switchgrass.Therefore,different prevention measures according to the different species and density should be taken to ensure the growth of switchgrass.