Establishing a core collection of Capsicum using a cluster analysis with enlightened selection of accessions

Abstract

A core collection represents the genetic diversity of a crop with minimal redundancy. A technique is proposed for establishing a representative core collection of Capsicum annuum L., C. chinense Jacq., and C. baccatum L. from the collection maintained at the Southern Plant Genetic Resources Conservation Unit, Griffin, GA, U.S.A. The accessions were stratified by species, and then cluster analyses were performed on the GRIN data for morphological descriptors of a given species. Three selection methods to form a core collection of approximately 10% of the collections were compared. Selecting one accession (equal number) from each cluster using either a random or a systematic selection procedure did not include all the existing morphological diversity. However, a third method, where selecting systematically a number of accessions per cluster based on the presence of unique traits allowed 100% of the known morphological diversity to be retained in the core collections of the three species.