Evaluation of Beauveria bassiana isolates for tolerance to organophosphorous pesticides by in vitro and SDS-Page analysis

By Padmini Palem P.C, Padmaja V and Varahalarao Vadlapudi


Entomopathogenic fungus Beauveria bassiana is an important biocontrol agent against major economic pests and is being employed in Integrated Pest Management (IPM) along with synthetic pesticides.  Twelve isolates of B. bassiana were evaluated for in vitro compatibility with four commonly used organophosphorous pesticide compounds to understand threshold concentrations of the test chemical permitting survival of the biocontrol agent.  Based on in vitro results, isolates of B. bassiana were categorized into more tolerant and less tolerant. Further biochemical analysis by SDS-PAGE method was carried out to detect markers in the isolates showing resistance and susceptibility towards organophosphorous pesticides. Triazophos, Dimethioate and Phosalone appeared to be compatible with B. bassiana isolates and SDS-PAGE analysis revealed prominent dissimilarities between more tolerant and less tolerant categories. Differential response of the isolates to a particular pesticide indicates differential tolerance limit of entomopathogenic fungal isolates. Electrophoretic protein banding patterns among the isolates of two categories enabled in ascertaining genetic relationship in terms of compatibility towards organophosphorous pesticides since mycelial proteins are the products of number of genes present in respective genomes.


Key Words : Beauveria bassiana, compatibility, organophosphorous pesticides, SDS-PAGE, IPM.

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