为研究酚酸类物质对苜蓿种子萌发的化感效应,采用培养皿滤纸培养法,测定 5 种不同浓度的酚酸类物质对苜蓿种子发芽率、发芽势、简易活力指数、胚根和胚轴长度及根毛发育的影响.结果表明:香豆素处理对苜蓿种子萌发的影响最为明显,当其浓度增大至 500 mg/L,种子基本不萌发、表面发黑、腐烂严重.咖啡酸对苜蓿种子活力的影响与香豆素相似,表现出显著抑制效应,但抑制幅度较为平缓,高于0.5 mg/L的香豆素处理和高于500 mg/L的咖啡酸显著抑制苜蓿胚根生长.高于50 mg/L的香豆素和咖啡酸处理对苜蓿种子的发芽率、发芽势、种子简易活力、根毛和胚轴生长均表现出抑制作用,与对照相比差异显著(P<0 .0 5 ).对羟基苯甲酸对苜蓿种子萌发的化感抑制作用最弱,化感效应综合指数为-0.026,50 mg/L的对羟基苯甲酸处理明显促进苜蓿胚根生长.各酚酸类物质对苜蓿种子萌发的化感抑制效应强弱顺序为:香豆素>咖啡酸>阿魏酸>绿原酸>对羟基苯甲酸.%The allelopathy of phenolic compounds on seed germination of alfalfa was studied by measuring the germination rate,germination potential,simple vigor index,radicle and hypocotyl length with filter paper culture method.The effects of phenolics on the root hair were observed by stereomicroscopy as well.The results showed that coumarin and caffeic acid treatments had inhibitory effects on germination rate,germination poten-tial,simple vigor index,root hair and hypocotyl growth when the concentration was over 50 mg/L,which was significantly different from control (P<0.01).The effect of coumarin on the seed germination of alfalfa was the strongest,especially when the concentration reached 500 mg/L,and the seeds did not germinate and were seri-ously rotten,and the surface of seeds was black.The treatment of hydroxybenzoic acid with concentration of 0 to 500 mg/L was the weakest for seed germination.The order of allelopathic inhibition was:coumarin>caffeic acid>ferulic acid>chlorogenic acid> p-Hydroxybenzoic acid.
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