Microsatellites to enhance characterization, conservation and breeding value of Capsicum germplasm

Abstract

Capsicum species are of great economic, medicinal, culinary and cultural value worldwide, however their genetic potential is still underutilized. In this study, a set of 21 microsatellite markers showed utility for distinguishing a diverse group of 42 Capsicum genotypes representing 11 species. The level of polymorphism among these genotypes was evaluated by calculating the polymorphic information content (PIC) and discriminating power (D) for each locus. A total of 208 alleles were detected at the 21 loci evaluated. Markers detecting the highest number of alleles also exhibited the highest number of rare alleles. PIC values and D estimations showed a significant positive correlation (r = 0.98; P < 0.0000). PIC values ranged between 0.500 (marker NG20) and 0.899 (marker NG17), giving an average of 0.775. Genetic relationships among genotypes were evaluated using UPGMA clustering, Principal Coordinate Analysis (PCoA) and Bayesian model-based clustering, allowing genotypes to be discriminated into groups according to their degree of genetic similarity corresponding to distinct taxa. Based on these analyses, the 21 microsatellite included in this study now define a standard tool for efficient assessment of molecular variability of Capsicum germplasm collections conserved worldwide.