Biological bar code for determining the geographical origin of fruits using 28S rDNA fingerprinting of fungal communities by PCR-DGGE: an application to Shea tree fruits

Abstract

Objectives Shea tree is a multi-purpose tree daily used by rural African communities. Economic importance of Shea tree fruits has been rising and achieving a great success in African, American and European markets. Shea butter is used mainly in chocolate industry, cosmetic or pharmacological products. Traceability is now one of the great concerns of the customers and the lawyers. In view of the difficulties of installing these documentary systems in developing country particularly the countries of sub-Saharan Africa, the new strategies of traceability emerge. Methods Molecular technique using 28S rDNA profiles generated by polymerase chain reaction denaturing gradient gel electrophoresis was used to detect the variation in fungal community structures of Shea tree fruit from Senegal, Mali and Cameroon. Results 28S rDNA profiles were analysed by multivariate analysis, distinct microbial communities were detected. Band profiles of Shea tree fruit fungi from different countries were specific for each location and could be used as a bar code to discriminate the origin of fruits. Conclusion We propose the polymerase chain reaction denaturing gradient gel electrophoresis method as the fingerprinting of Shea tree fruits using 28S rDNA of fungi that provides the fruits with a unique bar code and make it possible to trace back the Shea tree fruit to their original locations. (Resume d'auteur)