防风枯斑病的病原学及药剂敏感性

Pathogen and Fungicide Susceptibility of Saposhnikovia divaricata Blight Caused by Diaporthe angelicae

试验研究了防风枯斑病的病原学和病菌生物学特性及其药剂敏感性。通过病菌的分离及柯氏证病,获得3株病原菌;结合病原形态特征、培养学特性及r DNA-ITS、TUB2和TEF序列分析,确定引起防风枯斑病的病菌为Diaporthe angelicae。病菌生物学研究表明:菌丝生长及孢子产生的最适温度为25℃,最适p H为8;病菌在以麦芽糖和蔗糖为主要碳源的培养基上生长和产孢最佳;在以天门冬酰胺为主要氮源的培养基上生长最佳。病菌分生孢子在25℃时萌发率最高,孢子的致死温度为35℃;分生孢子在p H 8时萌发率最高;全光照有利于分生孢子萌发。病菌对23种杀菌剂的敏感性测定结果表明:病菌对30%氟菌唑WP、3%己唑醇·27%稻瘟灵EC、40%氟硅唑EC、55%硅唑·多菌灵WP、25%丙环唑EC、30%苯醚甲环唑SC、30%醚菌酯WP、250 mg/L吡唑醚菌酯EC、10%苯醚甲环唑WG、77%硫酸铜钙WP的敏感程度较高,其EC50<0.1 mg/L。

Biological characteristics of Diaporthe angelicae（ a new plant disease in China） and its susceptibility to fungicides were studied. Single spore isolation method was used to obtain 3 isolates.The pathogen which caused Saposhnikovia divaricata blight were identified as Diaporthe angelicae based on morphological characteristics,cultural characteristics and r DNA-ITS,TUB2 and TEF sequence analysis. The results of the biological characteristics of the pathogen showed that the suitable temperature for mycelial growth and spore production was 25 ℃,and the suitable p H was 8; Maltose and Sucrose as the main carbon sources were optimal for mycelial growth and spore production,Asparagine was the main nitrogen sources for mycelial growth and spore production. The germination rate of the conidia was the highest at 25 ℃,and the lethal temperature of the conidia was 35 ℃.The germination rate of the conidia was the highest when p H was 8. Light had positive effect on conidia germination. The mycelial growth rate was used to test the susceptibility of the pathogen to 23 fungi-cides. The pathogen was more sensitive to 30% triflumizole WP,3% hexaconazole,27% isoprothiolane EC,40% flusilazole EC,55% flusilazole · carbendazim WP,25% propiconazol EC,30%difenoconazole SC,30% kresoxim-methyl WP,250 mg/L pyraclostrobin EC,10% difenoconazole WG,and 77% copper calcium sulphate WP,the EC50 of which was all less than 0. 1 mg/L.