Identification of minimum descriptors for characterization of Capsicum spp. germplasm

Abstract

This study was proposed to select minimum descriptors to the characterization of accessions of Capsicum spp. from Embrapa Hortaliças germplasm bank, which are characterized mainly by qualitative data. From this collection, 893 (420 C. annuum, 106 C. baccatum, 307 C. chinense and 60 C. frutescens) were considered because they were completely characterized by 56 morphological descriptors. The statistical treatment was performed by factorial multiple correspondence analysis, combined with estimation of matrices of genetic dissimilarity among accessions for multicategoric data. Lists of minimum descriptors were proposed for the whole collection and for the subcollections related to the four cultivated species. Around thirty minimum descriptors were selected for each subcollection, maintaining a minimum of 0.90 for the correlation between the dissimilarity matrices that consider all the descriptors or only the selected minimum descriptors. These proposed lists allow a reduction of around 50% in the number of initial descriptors. The filament colour, mature fruit colour, number of locules, fruit position, origin, pungency, fruit surface, stem length, plant height and fruit length were selected as minimum descriptors, both to the whole collection and their subcollections. Most of these descriptors are related to the fruit traits of sweet and chilli peppers, which are important for genetic breeding of Capsicum because are related to storage, processing, marketing and consumption of commercial derived products.