江西樱花褐斑病菌的鉴定及其对杀菌剂的敏感性

Identification of the pathogen causing brown spot in Cerasus in Jiangxi and its sensitivity to fungicides

为明确江西樱花褐斑病病原菌的种类,以樱花典型褐斑病叶片为材料,采用组织分离法,通过形态特征鉴定并结合SSU、LSU、ITS、GAPDH、TEF、RPB2、Alt al和His 3等基因分子生物学方法进行病原鉴定。结果表明:江西樱花褐斑病病原菌为交链格孢(Alternaria alternata);采用生长速率法测定病原菌对10%苯醚甲环唑水粉散剂、12.5%烯唑醇可湿性粉剂、2×10^(8) cfu/g木霉可湿性粉剂、500 g/L异菌脲水悬浮剂、400 g/L氟硅唑乳油、325 g/L苯甲·嘧菌酯水悬浮剂、430 g/L戊唑醇水悬浮剂、250 g/L嘧菌酯水悬浮剂等8种药剂的敏感性,苯醚甲环唑、烯唑醇和木霉等对病原菌有明显的抑制作用,EC_(50)值分别为0.001、0.022 mg/L和0.168个孢子/mL。推荐这3种药剂作为江西樱花褐斑病防治的优选药剂。

To clarify the specific pathogentic species of brown spot in Cerasus Mill,typical infected leaves were used as materials.Traditional tissue separation method and morphological identification method were combined with analysis of multilocus of SSU,LSU,ITS,GAPDH,TEF,RPB2,Alt al and His 3 to identify the pathogen.And Alternaria alternata was identified as the pathogen of brown spot in Cerasus.The growth rate method was used to determine the sensitivity of the pathogen to 8 fungicides including 10%difenoconazole(WG),12.5%diniconazole(WP),2×10^(8) cfu/g trichoderma(WP),500 g/L isocarbazide(SC),400 g/L flusilazole(EC),325 g/L difenoconazole-azoxystrobin(SC),430 g/L tebuconazole(SC),250 g/L azoxystrobin(SC).Difenoconazole,diniconazole and trichoderma had stronger inhibitory effect against the pathogen,with the concentration for 50%of maximal effect(EC_(50))being 0.001 mg/L,0.022 mg/L and 0.168 spores/mL respectively.These three fungicides mentioned above were recommended as the best fungicides for the pathogen of brown spot in Cerasus in Jiangxi Province.