Data analysis for molecular characterization of plant genetic resources

Characterizations of plant genetic resources based on molecular markers have been increased in the last years. Studies using a broad range of markers applied on hundreds of plant species are the theoretical basis for inferring genetic diversity to propose both breeding and conservation strategies. Despite increased importance of molecular characterization in plant genetic resources, there is scarce information about analysis of this type of data. To fill this gap of information, this review discuss the rationale behind analyses achieved to study genetic relationship among accessions (within and between groups) and to identify accession, and also discuss the adequacy of some analyses and/or parameters for specific purposes. Genetic diversity within groups may be either quantified for the whole group (parameters to choose will depend on type of marker), or quantified and visualized for the relationships among individuals. Quantification parameters will be chosen depending on type of marker, reproduction mode and relatedness of individuals. Visualization is achieved by hierarchical and non-hierarchical methods. Genetic diversity between groups should be quantified either by analysis of molecular variance, or Nei's parameters, or Wright's F-statistics. Efficiency of accession identification can be evaluated by maximal probability of identical match by chance and number of resolved genotypes.