Characterization and classification of different genotypes in a population of Cucumis melo based on their ability to regenerate shoots from leaf explants

Variability of the in vitro organogenic response from leaf explants of a seed population of Cucumis melo L. cv. Cantaloupe Charentais was analyzed to detect genotypic variability among individual seeds for shoot regeneration. Variation in shoot regeneration frequency among plants from different seeds was compared to that found among clonal replicas of each original plant. Clonal propagation was performed using in vitro culture of apical and axillary buds of axenic plants to avoid somaclonal variation. Results demonstrate the existence of highly significant differences among plants from the seed population. Regeneration frequency of leaf explants derived from clonally propagated sets of a single plant can be described by a binomial distribution for each original plant coming from one seed. Using data from stochastic simulation, we studied the accuracy of different analyses to detect the presence of genotypic heterogeneity in a population. These analyses, together with our experimental design, allowed the separation of genotypes differing up to 5% in their regeneration ability. Results of this work should allow researchers to hypothesize about those genotypes that differ within a population and their frequency.