海南省潜伏香蕉果实的炭疽菌对特克多的抗药性

RESISTANCE OF QUIESCENT COLLETOTRICHUM MUSAE TO THIABENDAZOLE FROM HAINAN PROVINCE

对来自海南省13个地区的67个Colletotrichum musae（Berk. & Curt.）Arx菌株进行抗药性检测，所测菌株均表现出敏感，即未产生特克多抗药性。室内采用高浓度特克多和90～95%致死剂量紫外光进行抗性诱导，获得的抗性菌株均能在1000g/ml特克多的PDA培养基上生长，但EC50值相差很大，最高达130g/ml，而最低为0.87g/ml。抗性菌株对多菌灵和甲基托布津均表现正交互抗药性。连续无毒培养10代后，所有菌株仍可在5g/ml特克多的培养基上生长，表现抗性遗传稳定。抗性菌株的产孢能力和致病力与敏感菌相比并没有下降，表现很高的适应能力。

Sixty-seven isolates of Colletotrichum musae（Berk. & Curt.）Arx were isolated from banana in 13 regions of Hainan. Detection of resistance of the isolates to thiabendazole(TBZ) was conducted by determination of mycelial growth in PDA with 5g/ml of TBZ, all the wild isolates tested were not able to grow at 5g/ml of TBZ and therefore they were regarded as sensitive. However, isolates in different level of resistance were induced by using high concentration of TBZ and 90～95% lethal dose of UV in laboratory. Although all the resistant isolates were able to grow at as high as 1000g/ml of TBZ on PDA medium, their EC50value were significantly different, ranging from 0.87g/ml to 130g/ml. The TBZ-resistant isolates were also resistant to benzimidazole fungicides such as carbendazin and topsin-M, suggesting that the isolates of C. musae were cross-resistant to the three fungicides. After 10 successive transfers and incubations on the fungicide free PDA, all these resistant isolates were still able to grow at 5g/ml of TBZ, showing that the resistance of these isolates was stable. The capability of sporulation and pathogenicity of these resistant isolates were not significantly different from their respective wild isolates, showing their good adapting ability.