Examination of the sensitivity of Botryosphaeria berengeriana f. sp. pirico-la to tebuconazole

SU Ping; ZHOU Zeng-qiang; HOU Hui; WANG Li; ZHU Jian-lan

Abstract：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,Shan-dong 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 (EC_(50)) to the 47 strains for tebuconazole ranged from 0.005 4 to 3.325 3 mg·L~(-1),and the mean EC_(50) values (±Se×t0.05) were 0.266 7±0.208 3 mg.L~(-1). Isolate XX2B (EC_(50)3.325 3 mg·L~(-1)) showed the lowest sensitivity to tebuconazole, strain QF2 (EC_(50) 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 EC_(50) 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 evi-dent difference in the strains.