BACKGROUND: Grey mould caused by the fungus Botrytis cinerea Pers. ex Fr. is one of the major diseases in grapes. The use of fungicides is a simple strategy to protect grapes against B. cinerea disease. However, phenotypes exhibiting resistance to fungicides have been detected in B. cinerea populations. The variation of fungicide-resistant B. cinerea isolates renders B. cinerea disease control difficult in grapevine fields.
RESULTS: The authors have developed a nested polymerase chain reaction–restriction fragment length polymorphism (PCR-RFLP) method to detect fungicide-resistant B. cinerea isolates at an early growth stage of grapes in grapevine fields. The nested PCR-RFLP method was carried out to detect benzimidazole-, phenylcarbamate- and/or dicarboximide-resistant B. cinerea isolates from grape berries and leaves at Eichorn–Lorenz growth stage 25 to 29. This method successfully detected fungicide-resistant B. cinerea isolates at an early growth stage of grapes. In addition, only 8 h was required from tissue sampling to phenotyping of fungicide resistance of the isolates.
CONCLUSION: It is proposed that the early diagnosis of fungicide-resistant B. cinerea isolates would contribute to further improvement of integrated pest management against B. cinerea in grapevine fields, and that the nested PCR-RFLP method is a high-speed, sensitive and reliable tool for this purpose. Copyright © 2008 Society of Chemical Industry