Characterization and discrimination of Colombian Capsicum accessions using elliptic fourier analysis

Abstract Chillies are one of the most cultivated plants in the world. The species of the genus Capsicum have a wide range of uses in agriculture, as vegetables and spices, in medicine and as ornamental plants. In Colombia, chilli represents an important exported crop, but the morphological characterization of this genetic resource is still poor. In this way, the Elliptic Fourier Analysis (EFA) is a value tool to evaluate the morphological variation of any group as allow the application of geometric morphometric to structures that do not have homologous points or are difficult to assign as chili fruits. For this purpose, fruits from the departments of Cauca, Nariño and Valle del Cauca were collected in marketplaces, gardens and natural reserves. The accessions were identified based on morphological and molecular characteristics. Photos of each fruit were taken, digitized and used to obtain the coordinates of the fruit outline to perform an EFA. With the coefficients obtained from the EFA, a principal components analysis (PCA) and a clustering analysis were performed. Finally, a discriminant analysis was performed to differentiate the fruit outline of two Capsicum species. A total of 743 pepper fruits were collected, representing 160 accessions and 5 species ( C . annuum , C . frustescens , C . chinense , C . pubescens and C . baccatum ). Cluster analysis revealed five representative fruit shapes: long and curved, conical, asymmetrical conical, round and triangular. The wild accessions had round fruits, while the domesticated accessions had triangular, conical, asymmetrical conical and curved fruits. The discriminatory analysis made it possible to distinguish between C . annuum var. glabriusculum and C . frutescens wild, species that are difficult to identify on the basis of other morphological characters.