Establishment of the fungal entomopathogen Beauveria bassiana (Ascomycota: Hypocreales) as an endophyte in cocoa seedlings (Theobroma cacao)

Abstract

The fungal entomopathogen Beauveria bassiana became established as an endophyte in in vitro-grown cocoa seedlings tested for up to 2 mo after inoculation to the radicle with B. bassiana suspensions. The fungus was recovered in culture from stems, leaves and roots. B. bassiana also was detected as an epiphyte 1 and 2 mo postinoculation. Penicillium oxalicum and five bacterial morphospecies also were detected, indicating that these were present as endophytes in the seed.

• biological control
• cacao
• cocoa pod borer
• Conopomorpha
• entomopathogens
• insect pathogens

We thank J. de Souza (CEPLAC, Brazil) for providing cocoa seeds and for advice on cocoa endophytes; Cathie Aime, Pat Dowd, Matt Greenstone and Les Lewis (USDA, ARS), Betsy Arnold (University of Arizona) and Meredith Blackwell (Louisiana State University) for helpful suggestions and comments on a previous version of this manuscript; and S. Peterson (USDA, ARS) for identifying P. oxalicum. Special thanks to Ann Sidor for excellent laboratory assistance. This work was conducted as part of a Collaborative Research and Development Agreement with Masterfoods Inc. The use of trade, firm or corporation names in thisPUBLICation is for the information and convenience of the reader. Such use does not constitute an official endorsement or approval by the United States Department of Agriculture or the Agricultural Research Service of any product or service to the exclusion of others that may be suitable.