云南灯盏花根腐病的2种新病原鉴定及防治药剂的室内筛选

引起云南省灯盏花根腐病的病原为茄病镰刀菌(Fusarium solani)、尖孢镰刀菌(F.oxysporum)和半裸镰刀菌(F.semitectum)3种真菌，茄病镰刀菌和尖孢镰刀菌为灯盏花根腐病的2种新病原，其中茄病镰刀菌为主要致病菌，其分离率为42.86%，茄病镰刀菌有伤接种发病率为70%，无伤接种发病率为56.7%。采用室内生长速率法测定了50%多菌灵可湿性粉剂、70%甲基硫菌灵可湿性粉剂、64%恶霜·锰锌可湿性粉剂、10%苯醚甲环唑水分散粒剂、10亿活芽胞/g 枯草芽胞杆菌·荧光假单胞杆菌可湿性粉剂5种供试杀菌剂对灯盏花根腐病主要病原茄病镰刀菌的毒力。结果表明：5种供试药剂对茄病镰刀菌都有抑制作用。对茄病镰刀菌的有效中浓度（EC50）分别为0.000 4、0.050 7、0.053 5、0.081 3和8.624 0 mg/mL，其中50%多菌灵可湿性粉剂有效中浓度最低，相对抑制效果最好。5种药剂的毒力相关系数均在0.89以上，表明药剂质量浓度与抑制作用呈较高相关性。

Identification of the two new pathogens of root rot disease on Erigeron breviscapus and screening of fungicides

The three pathogens causing root rot of Erigeron breviscapus in Yunnan Province were identified as Fusariumsolani, F.oxysporum and F.semitectum, among which F. solani and F.oxysporum were two new pathogens; the main pathogen was F.solani, and the isolation frequency was 42.86%. After artificial inoculation with or without wounds, the incidence of roots infected by F.solani was 70% and 56.7%, respectively. With mycelium growth rate test method, five fungicides to F.solani had inhibition effects, indicating that the EC 50 values of 50% carbendazim WP, 70% thiophanate methyl WP, 64% oxadixyl·mancozeb WP, 10% difenoconazole WG, and 1 billion live spores of Bacillus subtilis and Pseudomonas fluorescens WP were 0.000 4 mg/mL, 0.050 7 mg/mL, 0.053 5 mg/mL, 0.081 3 mg/mL and 8.624 0 mg/mL, respectively, suggesting that 50% carbendazim WP was the best. The correlation coefficients for the five fungicides were all above 0.89, indicating that mass concentration had high correlation with inhibition.