Restriction fragment length polymorphism and genetic distance among Mexican accessions of Capsicum

Restriction fragment length polymorphism analysis was performed on 25 accessions of pepper (Capsicum sp.) from various regions of Mexico and on the two parents currently in use for molecular mapping. The fragments detected were used to estimate genetic distances among the accessions. A dendrogram from cluster analysis and a principal component analysis diagram of the genetic distance matrix are presented. The correlation between genetic distances measured by restriction fragment length polymorphism versus genetic distances measured by isozymes is good (R2 = 0.438, p = 0.0001). All but four accessions could be differentiated with the 10 most polymorphic clones examined. Crosses were made between each of our two mapping parents and the Mexican accessions as well as among many of the Mexican accessions. F1 pollen stainability data were taken to estimate the fertility of each cross. This information along with the genetic distance data is used to select polymorphic but interfertile parents for future restriction fragment length polymorphism mapping in pepper.Key words: pepper, cluster analysis, isozyme-RFLP correlation, DNA fingerprinting.