苹果轮纹病菌对戊唑醇的敏感性检测

为了明确苹果轮纹病菌对三唑类杀菌剂戊唑醇的敏感性现状,从有代表性的苹果种植区采集、分离了47个苹果轮纹病菌(Botryosphaeria berengeriana f.sp.Piricola)菌株,采用菌丝生长速率法测定其对戊唑醇的敏感性。结果表明,戊唑醇对47个菌株的EC50值在0.0054～3.3253mg·L-1,平均值为0.4359±0.1902mg·L-1。其中,菌株XX2B(EC50为3.3253mg·L-1)对戊唑醇的敏感性较低,QF2(EC50为0.0054mg·L-1)对其最敏感,其毒力倍数是XX2B的620.38倍。山东省、河南省和辽宁省的苹果轮纹菌对戊唑醇的EC50平均值分别为0.5715±0.4612mg·L-1、0.4119±0.2157mg·L-1和0.2667±0.2083mg·L-1,表明辽宁省的苹果轮纹菌对戊唑醇的敏感程度最高,山东省的敏感性最低。但不同地理来源的苹果轮纹病菌对戊唑醇的敏感性差异不明显。

Examination of the sensitivity of Botryosphaeria berengeriana f. sp. piricola to tebuconazole

To confirm the sensitivity of Botryosphaeria berengeriana f. sp. piricola to triazole fungicides tebuconazole,47 strains of Botryosphaeria berengeriana f. sp. piricola were isolated from typical and representative location of Henan,Shandong and Liaoning Province. The sensitivities of 47 strains to triazole fungicide tebuconazole were measured by colonial growth-rate. The result showed that the 50% effective concentration values (EC50) to the 47 strains for tebuconazole ranged from 0.005 4 to 3.325 3 mg·L-1,and the mean EC50 values (±Se×t0.05) were 0.266 7±0.208 3 mg·L-1. Isolate XX2B (EC50 3.325 3 mg·L-1) showed the lowest sensitivity to tebuconazole,strain QF2 (EC50 0.005 4 mg·L-1)was the most sensitive strain to tebuconazole,whose toxicity ratio was 620.38-fold compared to strain XX2B. Furthermore,the mean EC50 values of Shan-dong,Henan,and Liaoning Province were 0.571 5±0.461 2 mg·L-1,0.411 9±0.215 7 mg·L-1 and 0.266 7±0.208 3 mg·L-1,separately. This showed that the isolates from Liaoning were more sensitive to tebuconazole than the isolates from Shandong and Henan,the sensitivity of strain from Shandong was the lowest. The result of Duncan test and hierarchical cluster analysis showed that the sensitivities to tebuconazole of Botryosphaeria berengeriana f. sp. piricola from different regions were no evident difference in the strains.