Determination of fruit origin by using 28S rDNA fingerprinting of fungi communities by PCR-DGGE: an application to Physalis fruits from Egypt, Uganda and Colombia

Abstract

Introduction. Consumption of Physalis fruits is quite recent and the products are poorly known among consumers. This plant has been known for a long time as an ornamental in Europe, for at least 200 years. Traceability is increasingly becoming important across the agri-food industry; however, at the present time, the traceability of this fruit is only documentary. In case of doubt or fraud, no standardized analysis can determine the geographical origin of the fruits. Materials and methods. In order to discover the relationship between the fungal communities of the fruit and their geographical origins, 28S rDNA-PCRDGGE was used to analyze the variation in fungal communities in three species of Physalis fruit (Physalis ixocarpa Brot., Physalis pruinosa L. and Physalis peruviana L.) from Egypt, Uganda and Colombia. Results. Denaturing Gradient Gel Electrophoresis (DGGE) fingerprints of 28S ribosomal DNA (28S rDNA) analyzed by multivariate analysis could distinguish different fruit origins by their fungal communities. Conclusion. We propose the PCR-DGGE method as a new traceability tool which provides fruit in general, and Physalis in particular, with a unique barcode for each country by using 28S rDNA fingerprinting of fungi. (Resume d'auteur)