马缨杜鹃炭疽病病原菌生物学特性及防治药剂筛选  

Biological characteristics of pathogenic anthracnose Colletotrichum fioriniae on Rhododendron delavayi and screening of fungicides

作　　者：胡珊 莫维弟 周志成 丁海霞[2,3] 彭丽娟 HU Shan;MO Weidi;ZHOU Zhicheng;DING Haixia;PENG Lijuan(College of Tobacco Science,Guizhou University/Guizhou Key Laboratory for Tobacco Quality Research,Guiyang 550025,China;College of Agriculture,Guizhou University,Guiyang 550025,China;Guizhou Key Laboratory of Agricultural Biotechnology/Guizhou Academy of Agricultural Sciences,Guiyang 550006,China)

机构地区：[1]贵州大学烟草学院/贵州省烟草品质研究重点实验室,贵州贵阳550025 [2]贵州大学农学院,贵州贵阳550025 [3]贵州省农业生物技术重点实验室/贵州省农业科学院,贵州贵阳550006

出　　处：《华南农业大学学报》2023年第4期570-576,共7页Journal of South China Agricultural University

基　　金：国家重点研发计划(2017YFD0201605);中国博士后科学基金(2020M683658XB);贵州省教育厅青年科技人才成长项目(黔教合KY字[2018]101);贵州省林业优秀青年人才培养专项资金(黔林科合J[2018]08);贵州省科技计划(黔科合服企[2019]4016)。

摘　　要：【目的】探明贵州百里杜鹃自然保护区马缨杜鹃Rhododendron delavayi炭疽病菌Colletotrichum fioriniae生物学特性,并筛选出有效药剂。【方法】采用菌丝生长速率法测定马缨杜鹃炭疽病菌生物学特性;选用二氰蒽醌、吡唑醚菌酯、溴菌腈、丙环唑、苯醚甲环唑、肟菌·戊唑醇、四霉素、乙蒜素、蛇床子素及宁南霉素对该病原菌的室内毒力进行测定;选择作用机制不同、抑菌活性较高的2种药剂按不同比例复配,测定其对马缨杜鹃炭疽病菌菌丝的联合毒力。【结果】病原菌在5~35℃、pH 5~11均能生长,最适温度为25℃,最适生长pH为8,最适碳源为葡萄糖和可溶性淀粉,最适氮源为蛋白胨,最适培养基为PSA。室内毒力测定结果表明,所选药剂对病原菌菌丝生长均有一定抑制作用,其中,肟菌·戊唑醇、吡唑醚菌酯、四霉素、苯醚甲环唑和丙环唑抑制效果较好,EC50分别为0.102、0.118、1.107、1.202和2.101 mg/L;其次为蛇床子素,EC50为6.803 mg/L。选用四霉素与苯醚甲环唑进行混配,结果表明不同配比对病原菌的联合毒力较单剂均具有协同增效作用,增效最佳配比为7∶3,共毒系数(Co-toxicity coeffecient,CTC)达584.56,明显高于其他配比;配比为6∶4和8∶2时,对应CTC均在500以上,仅次于最佳配比。【结论】马缨杜鹃炭疽病菌的生长受温度、pH、培养基成分、碳氮源影响明显。四霉素和苯醚甲环唑不同比例复配活性增效明显,可选择7∶3复配比例进行田间防治。【Objective】To investigate the biological characteristics of Colletotrichum fioriniae on Rhododendron delavayi in Baili Azalea Nature Reserve of Guizhou Province,and to screen effective fungicides for disease control.【Method】The mycelial growth rate method was applied to explore the biological characteristics of C.fioriniae on R.delavayi.The indoor toxicity of pathogen was determined using 10 fungicides,including trifloxystrobin·tebuconazole,pyraclostrobin,difenoconazole,propiconazole,bromothalonil,dithianon,tetramycin,ethylicin,cnidiadin and ningnanmycin.Combined toxicity of two fungicides with high antifungal activities and different toxicological mechanisms to C.fioriniae was assessed in different mixture ratio.【Result】The pathogenic fungi could grow under 5−35℃and pH 5−11.The optimum temperature was 25℃and the optimum pH was 8.The best carbon sources were glucose and soluble starch.Peptone was the best nitrogen source for the pathogen growth and the growth rate reached the maximum on PSA medium.The results of the indoor toxicity test indicated that all of the 10 fungicides inhibited the mycelial growth of the pathogen to some extent.Among 10 fungicides,trifloxystrobin·tebuconazole,pyraclostrobin,tetramycin,difenoconazole,and propiconazole had better inhibitory effect with EC50 of 0.102,0.118,1.107,1.202 and 2.101 mg/L,respectively,followed by cnidiadin with EC50 of 6.803 mg/L.The combination of tetramycin and difenoconazole with different mixture ratio showed synergistic inhibiting effect on the pathogen compared with single fungicide.The optimal mixture ratio was 7∶3 with co-toxicity coefficient(CTC)of 584.56,which was obviously higher than those of other mixture ratios.Both the mixture ratio of 6∶4 and 8∶2 had CTC above 500,being next to the best ratio.【Conclusion】The growth of C.fioriniae is significantly affected by temperature,pH,culture medium,carbon and nitrogen sources.The combination of tetramycin and difenoconazole in different mixture ratios has obvious synergistic to

关 键 词：马缨杜鹃 松针炭疽菌 生物学特性 联合毒力测定 

分 类 号：S432[农业科学—植物病理学]