Abstract: In order to investigate the allelopathic potential of bermudagrass(Cynodon dactylon Rich.) in weed management,a laboratory bioassay was conducted with Italian ryegrass(Lolium multiflorum Lam.),annual bluegrass(Poa annua L.),common crabgrass(Digitaria sanguinalis(L.) Scop.),barnyardgrass(Echinochloa crusgalli(L.) Beauv.) and goosegrass(Eleusine indica(L.) Gaerth.) as the acceptors.Effects of the aqueous extracts of aboveground part of bermudagrasses on seed germination rate and seeding growth of the acceptors were investigated,and 9 phenolic acids namely protocatechuic,caffeic,salicylic,syringic,ferulic,vanillic,ρ-coumaric,cinnamonic,and ρ-hydroxybenzoic acids in the aqueous extracts were quantified by high performance liquid chromatography(HPLC).The results show that the germination and seedling growth of 5 acceptor grasses,especially Italian ryegrass,common crabgrass and goosegrass,were inhibited obviously by applying the aqueous extracts,and inhibition rate by wild bermudagrass was greater than Tif-419 and Tif-328.Vanillic,ρ-coumaric and ferulic acids were detected in all of the water extracts of 4 bermudagrasses,and the protocatechuic,caffeic,salicylic,syringic,ρ-hydroxybenzoic,and cinnamonic aids were only detected in some of the aquesous extracts of the bermudagrass materials.Compared with other phenolic acids,concentration of protocatechuic acid in the aqueous extract was highest,and the change of protocatechuic acid concentration was consistent with the inhibition of the aqueous extracts on seed germination rate and seeding growth of the acceptors.Therefore,protocatechuic acid might be the most effective phenolic acid in bermudagrass on the inhibition of seed germination and seeding growth of acceptor grasses.

Key words: Bermudagrass, Allelopathic effect, Weed, Inhibition

摘要： 为探讨狗牙根(Cynodon dactylon Rich.)化感作用在杂草防除中应用的可行性,以培养皿砂培法研究了狗牙根不同材料茎叶水浸提液处理对多花黑麦草(Lolium multiflorum Lam.),一年生早熟禾(Poa annua L.),马唐(Digitaria sanguinalis (L.) Scop.),稗草(Echinochloa crusgalli (L.) Beauv.)和牛筋草(Eleusine indica (L.) Gaerth.)等的化感作用;并利用高效液相色谱(HPLC)法检测了狗牙根茎叶水浸提液中原儿茶酸、咖啡酸、邻羟基苯甲酸、丁香酸、阿魏酸、香草酸、香豆酸、水杨酸、肉桂酸等9种酚酸的含量。结果表明:狗牙根水浸提液处理对5种禾草种子萌发及幼苗生长均产生显著的化感抑制作用(P<0.05),对多花黑麦草、马唐和牛筋草的抑制作用尤为明显;野生普通狗牙根的化感抑制作用强于育成品种。供试的4个狗牙根材料水浸提液中均检测到香草酸、香豆酸和阿魏酸,但仅在部分材料水浸提液中检测到原儿茶酸、咖啡酸、邻羟基苯甲酸、丁香酸、水杨酸和肉桂酸;供试狗牙根材料中,3个材料水浸提液的原儿茶酸含量最高,且其含量的变化与水浸提液处理对禾草种子萌发、幼苗生长的抑制作用强弱顺序基本一致。因此,原儿茶酸可能是狗牙根茎叶中对多花黑麦草、马唐和牛筋草发挥化感抑制作用最大的酚酸物质。