北苍术立枯病病原鉴定及药剂优选

Pathogen Identification and Fungicides Screened of Seedling Blight on Atractylodes Chinensis

对内蒙古莫旗地区北苍术(Atractylodes chinensis)立枯病进行症状描述。通过组织分离和单丝纯化获得10个形态特征基本一致的分离物,柯氏法则验证分离物均可致病。结合病原形态学特征及rDNA-ITS序列分析结果,确定该病害由Rhizoctonia solani AG1-1B融合群引起。病原菌的生物学特性表明:菌丝较适宜生长温度为25℃;较佳的培养基为PSA和V8;较佳的碳源为山梨醇和蔗糖;较佳的氮源为L-丙氨酸和硝酸钾;pH为8时最适宜菌丝生长,光照条件对菌丝的生长没有影响;菌丝致死温度和时间分别为48℃,10 min。采用生长速率法测定了病原菌对27种杀菌剂的敏感性。研究结果表明,病原菌对430 g/L戊唑醇SC、25%肟菌·50%戊唑醇WG、5%唑醚·55%代森联WG的敏感性较强,EC50<0.1 mg/L;40%菌核净WP、10%多抗霉素WP、40%氟硅唑EC、25%吡唑醚菌酯EC、10%苯醚甲环唑WG、50%多菌灵WP、75%百菌清WP、50%腐霉利WP、250 g/L嘧菌酯SC、10%甲霜·48%锰锌WP、50%氟菌唑WP敏感性次之,0.1 mg/L<EC50<1 mg/L。

The symptoms of Atractylodes chinensis in Moqi area, Inner Mongolia were described. Ten isolates with identical morphology were obtained by tissue isolation and single hyphae purification. Pathogenicity of ten isolates were confirmed by Koch’s Rule. The pathogen was determined to be caused by the Rhizoctonia Solani AG1-1 B fusion group by combining morphological characteristics and rDNA-ITS sequence analysis. When pH is 8, it is the most suitable for mycelia growth, and the light condition has no influence on the growth of mycelia. The lethal temperature and time of mycelia were 48℃ and 10 min, respectively. The sensitivity of the pathogen to 27 fungicides was determined by growth rate method. The pathogen was more sensitive to 430 g/L Tebuconazole SC, 25% Trifloxystrobin · 50% Tebuconazole WG, 5% Pyraclostrobin · 55% metiram WG, EC50<0.1 mg/L. The sensitivity of40% Dimetachlone WP, 10% Polyoxin WP, 40% Flusilazole EC, 25% Pyraclostrobin EC, 10% Difenoconazole WG,50% Carbendazim WP, 75% Chlorothalonil WP, 50% Procymidone WP, 250 g/L Azoxystrobin SC, 10% Metalaxyl ·48% Mancozeb WP, 50% Triflumizole WP was followed by with 0.1 mg/L<EC50<1 mg/L.