中文摘要：

腔孢叶斑病是牡丹生产上出现的一种新病害,近几年在洛阳及菏泽牡丹种植园危害越来越重。为了筛选防治该病的化学药剂,本文采用菌丝生长速率法测定了3类8种杀菌剂对病菌菌丝生长的抑制活性,采用涂布平板法测定了多菌灵、戊唑醇及嘧菌酯对病菌孢子萌发和芽管伸长的影响,并在含药平板上测定了3种药剂对病菌产孢量的作用。结果表明：三唑类药剂对病菌菌丝生长的毒力最强,EC50为0.020～0.096μg/mL,且戊唑醇对孢子萌发和产孢也有很强的抑制活性,在0.1μg/mL时孢子即不能萌发;甲氧基丙烯酸酯类药剂对菌丝生长的毒力较强,EC50为0.408～0.939μg/mL,嘧菌酯对芽管伸长和产孢量均表现出很强的抑制活性,10μg/mL时,芽管几乎不再伸长,对产孢的抑制率可达到99%以上;而苯并咪唑类药剂对菌丝生长的毒力较弱,EC50为12.167～30.104μg/mL,多菌灵对孢子萌发的抑制作用弱,100μg/mL时孢子萌发率仍达到90%以上,对产孢的抑制作用也较弱,为63.02%。根据药剂对病菌生长和发育各阶段的影响,生产中应采用适宜的施用方法：戊唑醇和嘧菌酯可作为保护剂在病害发生前期喷施,也可作为治疗剂在病害发生流行期应用,但为防止抗药性菌株的出现,两者应当轮换或复配使用。

英文摘要：

Peony coelomycete leaf spot,a new disease whose causal agent was Hainesia lythri on peony leaf,occurred more and more commonly in peony gardens in Luoyang and Heze.In order to screen fungicides for controlling the disease,the inhibitory activity of eight fungicides against mycelial growth was measured and the efficacy of carbendazim,tebuconazole and azoxystrobin on conidial germination and sporulation was determined in this study.The results showed that triazoles fungicides,including tebuconazole,epoxiconazole,propiconazole and difenoconazole,could strongly inhibit the mycelial growth with the EC50 value from0.020 to 0.096μg/mL.The inhibitory activity of tebuconazole on conidial germination rate was the strongest,which could cause the conidia to stop germination even at the concentration of 0.1μg/mL.Strobilurins fungicides,including azoxystrobin and kresoxim-methyl,could also inhibit the mycelial growth with the EC50 value from0.408 to 0.939μg/mL.Azoxystrobin had strong inhibitory activity against germ tube growth and sporulation,indicating that it could cause the cease of germ tube growth at the concentration of 10μg/mL and the inhibition rate of sporulation could reach beyond99%.Benzimidazoles fungicides,including carbendazim and thiophanate-methyl,had lower inhibitory activity on mycelial growth rate with the EC50 value from12.167 to 30.104μg/mL.For carbendazim,the germination rate of conidia could still exceed 90% even at the concentration of 100μg/mL and the inhibition rate of sporulation was only 63.02%,implying that the inhibitory activity was weaker.Tebuconazole and azoxystrobin could be used as protective fungicides before the appearance of the peony coelomycete leaf spot and also as curative fungicides when the disease becomes more prevalent.To delay the onset of resistance,alternate and mixed use of the two fungicides is recommended.