BACKGROUND:Venturia inaequalis(Cooke)Winterwithreducedsensitivity to strobilurinshasbeenreportedin several countries, including Italy. This study aimed to characterise the sensitivity to strobilurins of threedifferent types of V. inaequalis population: (a) wild types; (b) from commercial orchards satisfactorily managed with strobilurins; (c) from an experimental orchard with control failures by trifloxystrobin and kresoxim-methyl. In vitro sensitivity tests included antigerminative activity on population conidia and mycelial growth inhibition on monoconidial isolates. Cleaved amplified polymorphic sequence (CAPS) analysiswas used for the detection of G143A substitution. RESULTS: Wild-type populations showed EC50 values lower than 0.031 mg L−1, while those of orchards with good performance by strobilurins presented EC50 values never higher than 0.063 mg L−1. Samples with scab control failures showed a strongly reducedpopulation sensitivity. Similardifferences were confirmed in monoconidial isolates. TheG143Asubstitution was always detected in low-sensitivity populations, only sometimes in well-controlled populations and generally not in wild types. CONCLUSIONS: In vitro sensitivity assays were able to discriminate the three population typeswith different scab management, while thequalitativePCRanalysis (CAPS)wasonlypartially reliable. High sensitivitydifferencesamongV.inaequalis populations with good and poor field control by strobilurins were observed.
Fiaccadori R., Cicognani E., Alberoni G., Collina M., Brunelli A. (2011). Sensitivity to strobilurin fungicides of Italian Venturia inaequalis populations with different origin and scab control. PEST MANAGEMENT SCIENCE, 67, 535-540 [10.1002/ps.2090].
Sensitivity to strobilurin fungicides of Italian Venturia inaequalis populations with different origin and scab control
FIACCADORI, RICCARDO;ALBERONI, GIULIA;COLLINA, MARINA;BRUNELLI, AGOSTINO
2011
Abstract
BACKGROUND:Venturia inaequalis(Cooke)Winterwithreducedsensitivity to strobilurinshasbeenreportedin several countries, including Italy. This study aimed to characterise the sensitivity to strobilurins of threedifferent types of V. inaequalis population: (a) wild types; (b) from commercial orchards satisfactorily managed with strobilurins; (c) from an experimental orchard with control failures by trifloxystrobin and kresoxim-methyl. In vitro sensitivity tests included antigerminative activity on population conidia and mycelial growth inhibition on monoconidial isolates. Cleaved amplified polymorphic sequence (CAPS) analysiswas used for the detection of G143A substitution. RESULTS: Wild-type populations showed EC50 values lower than 0.031 mg L−1, while those of orchards with good performance by strobilurins presented EC50 values never higher than 0.063 mg L−1. Samples with scab control failures showed a strongly reducedpopulation sensitivity. Similardifferences were confirmed in monoconidial isolates. TheG143Asubstitution was always detected in low-sensitivity populations, only sometimes in well-controlled populations and generally not in wild types. CONCLUSIONS: In vitro sensitivity assays were able to discriminate the three population typeswith different scab management, while thequalitativePCRanalysis (CAPS)wasonlypartially reliable. High sensitivitydifferencesamongV.inaequalis populations with good and poor field control by strobilurins were observed.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
