燕麦叶斑病菌的鉴定及防治药剂室内筛选

Identification and Laboratory Screening of Chemical Agents of Oat Leaf Spot Pathogens

为鉴定燕麦叶斑病菌、筛选防治该病害的有效杀菌剂,结合形态学特征和rDNA-ITS序列,对青海省西宁市大通县燕麦叶斑病菌进行了鉴定,并测定了不同碳、氮源对病原菌菌丝生长的影响情况;进一步地,采用菌丝生长速率法测定8种杀菌剂对病原菌的抑制作用。结果发现,分离得到的43株燕麦叶斑病菌为燕麦内脐蠕孢(Drechslera avenae)。比较7种碳源和8种氮源对病原菌菌丝生长的影响,发现供试碳源果糖和氮源酵母提取物对燕麦内脐蠕孢菌丝生长的促进作用最为明显。室内药剂筛选试验表明,吡唑醚菌酯和咯菌腈对燕麦叶斑病菌有较好的抑制作用,EC50值分别为0.894 mg·L^(-1)和3.656 mg·L^(-1);而苯醚甲环唑、戊唑醇和代森联的抑制作用较差,EC50值在9.145 mg·L^(-1)~12.850 mg·L^(-1)之间。研究结果可为燕麦生产过程中使用杀菌剂防治燕麦叶斑病提供科学依据。

In order to identify the leaf spot pathogen of oat and filtrate the control agents of the pathogen,we i⁃dentified the pathogen of oat leaf spot in Dalong Village,Datong County,Xining City,Qinghai Province based on morphological characteristics and rDNA-ITS sequence analysis.Then,the effects of different carbon and nitrogen sources on mycelia growth of pathogens were determined.Furthermore,the inhibition effects of 8 fungicides on the fungi pathogens were also determined using the mycelial growth rate method.The results showed that 43 isolates from leaf spot were all the Drechslera avenae.Comparing the effects of 7 carbon sources and 8 nitrogen sources on mycelia growth found that fructose and yeast extract had the best acceleration.Laboratory filtrating test demonstra⁃ted that pyrazolesterin and fludioxonil both had a good inhibitory effect on D.avenaeand the EC50 values were 0.894 mg·L^(-1) and 3.656 mg·L^(-1),respectively.However,the inhibition effects of difenoconazole,tebuconazole and metiram were poor.Concretely,the EC50values ranged from 9.145 to 3.656 mg·L^(-1).The results would provide a scientific basis for controlling oat leaf spot in the process of production.