摘要：【目的】对兜兰炭疽病病原菌进行鉴定，并进行室内防治药剂筛选，为兜兰炭疽病的大田防控提供参考依据。【方法】采集具有典型症状的兜兰炭疽病标本，以组织分离法进行病原物分离培养，通过形态学观察和rDNA-ITS序列分析對兜兰炭疽病病原菌进行鉴定；通过室内温度、光照控制和培养基中不同pH、碳源、氮源的差异试验确定病原菌菌丝生长、产孢量和孢子萌发条件等生物学特性；选用12种杀菌剂进行兜兰炭疽病病原菌室内药效试验，并对筛选出效果理想的药剂进行室内毒力测定。【结果】通过形态学观察和rDNA-ITS序列分析，确定分离获得的兜兰炭疽病病原菌的无性态为半知菌类黑盘孢目刺盘孢属胶孢炭疽菌（Colletotrichum gloeosporioides）。胶孢炭疽菌菌丝生长和分生孢子萌发温度为9～36 ℃，最适温度27 ℃；产孢温度12～36 ℃，最适温度30 ℃。胶孢炭疽菌菌丝在55 ℃下处理20 min死亡，孢子在50 ℃下处理30 min或55 ℃下处理20 min死亡。菌丝生长和产孢的pH为2～13，最适为pH 8；分生孢子萌发的pH为2～12，最适为pH 7。连续光照有利于胶孢炭疽菌菌丝生长、产孢及分生孢子萌发。培养基中不同碳源和氮源对菌丝生长、产孢及分生孢子萌发具有显著影响（P<0.05）。500 mg/L的恶霉灵、硫磺·甲硫灵、福·福锌和咪鲜胺锰盐4种杀菌剂对胶孢炭疽菌菌丝抑制率和产孢抑制率均达100.00%，其中咪鲜胺锰盐的毒力最强、反应灵敏度最高，半最大效应浓度（EC50）为0.09 mg/L。【结论】引起兜兰炭疽病的病原菌为胶孢炭疽菌（C. gloeosporioides）。咪鲜胺锰盐、硫磺·甲硫灵、恶霉灵和福·福锌4种杀菌剂可在室内有效防治兜兰炭疽病，其中以500 mg/L咪鲜胺锰盐的防治效果最佳。
关键词： 兜兰；炭疽病；病原鉴定；生物学特性；杀菌剂筛选
中图分类号： S436.611 文献标志码：A 文章编号：2095-1191（2018）02-0271-09
Abstract：【Objective】Anthracnose pathogen of Paphiopedilum was identified and indoor control chemicals were selected to provide theoretical basis for prevention and control of Paphiopedilum anthracnose. 【Method】The samples of Paphiopedilum with typical anthracnose symptoms were collected. The pathogen was isolated and cultured through tissue isolation. Anthracnose pathogen of Paphiopedilum was identified by morphological observation and rDNA-ITS sequence analysis. The biological characteristics such as pathogen mycelial growth， spore production and spore germination were determined by experiment including indoor temperature， illumination and culture media with different pH values， carbon and nitrogen sources. Sensitivity to 12 fungicides of anthracnose pathogen of Paphiopedilum was tested and then fungicides with fine effects were selected to conduct indoor toxicity test. 【Result】 Through morphological observation and rDNA-ITS sequence analysis， the anamorph of isolated anthracnose pathogen of Paphiopedilum was Colletotrichum gloeosporioides， belonging to Colletotrichum， Melanconiales， fungi imperfecti. The temperature for mycelial growth and conidial germination was 9 ℃ to 36 ℃， and the optimal temperature was 27 ℃. Sporulation temperature was 12-36 ℃， and the optimum temperature was 30 ℃. Lethal temperature for C. gloeosporioides mycelia was 55 ℃ maintaining for 20 min， and lethal temperature of conidia was 50 ℃ maintaining for 30 min or 55 ℃ maintaining for 20 min. pH range for both mycelial growth and sporulation was 2-13 and the optimum pH for the both was 8. pH range for conidial germination was 2-12 and the optimum one was 7. Continuous illumination was good for mycelial growth， sporulation and conidial germination. The carbon and nitrogen sources in media had significant difference on mycelial growth， sporulation and conidial germination（P<0.05）. Under the concentration 500 mg/L， hymexazol， sulfur·Jialiulin， Fufuxin and prochloraz-manganese chloride complex could effectively control mycelial growth and sporulation of anthracnose pathogen，the success rates were both 100.00%. Among the four fungicides， prochloraz had the strongest toxicity and reaction sensitivity， and its concentration for 50% of maximum effect（EC50） was 0.09 mg/L. 【Conclusion】The anthracnose pathogen of Paphiopedilum is Colletotrichum gloeosporioides. Hymexazol， sulfur·Jialiulin， Fufuxin and prochloraz can effectively control Paphiopedilum anthracnose， and prochloraz-manganese chloride complex with concentration of 500 mg/L has the best control effects.