海南芒果蒂腐病菌对吡唑醚菌酯的抗药性测定

从海南芒果主产区采集分离蒂腐病菌Botryodiplodia theobromae。首先采用区分剂量法检测供试菌株对吡唑醚菌酯的抗药性,然后再采用生长速率法测定吡唑醚菌酯对蒂腐病菌的EC_(50)。结果表明:95株芒果蒂腐病菌中有56株在含10mg/L吡唑醚菌酯的PDA培养基中菌落直径大于空白对照的40%,抗性频率为58.95%,来自不同产区的芒果蒂腐病菌对吡唑醚菌酯的抗性频率差异不大。吡唑醚菌酯对供试菌株的EC50在3.12~1525.43mg/L之间,呈连续性正态分布,而抗性最高的菌株的EC_(50)是最敏感菌株EC50的488.92倍。敏感菌株、低抗菌株、中抗菌株及高抗菌株的平均EC_(50)分别为:5.39mg/L、45.34mg/L、144.72mg/L和514.46mg/L。海南芒果蒂腐病菌对吡唑醚菌酯杀菌剂已经产生严重的抗药性。

Resistance of Botryodiplodia theobromae caused mangostem end rot to pyraclostrobin in Hainan

The strains of Botryodiplodia theobromae causing mango stem end rot were collected from mango orchard in Hainan Province. The resistance of these strains to pyraclostrobin was tested by distinguishing dosage methods in laboratory. The concentration for 50% of maximal effect of pyraclostrobin to these strains was tested by growth rate method. The results showed that the resistance frequency of the tested isolates was 58.95%, which had no significant difference among strains from six mango areas. The EC50 values ranged from 3.12 mg/L to 1525.43 mg/L with continuous normal distribution. The maximum resistance factor was 488.92. The EC50 values of the sensitive strains were 5.39 mg/L, while the values of the low resistance strains, the moderate resistance strains and the highly resistance strains were 45.34 mg/L and 144.72 mg/L and 514.46 mg/L respectively. The data showed that B. theobromae causing mango stem end rot has developed a common resistance to pyraclostrobin in Hainan.