A method for combining molecular markers and phenotypic attributes for classifying plant genotypes

Classifying genotypes into clusters based on DNA fingerprinting, and/or agr onomic attributes. for studying genetic and phenotypic diversity is a commo n practice. Researchers are interested in knowing the minimum number of fra gments (and markers) needed for finding the underlying structural patterns of diversity in a population of interest. and using this information in con junction with the phenotypic attributes to obtain more precise clusters of genotypes. The objectives of this study are to present: (1) a retrospective method of analysis for selecting a minimum number of fragments (and marker s) from a study needed to produce the same classification of genotypes as t hat obtained using all the fragments (and markers), and (2) a classificatio n strategy for genotypes that allows the combination of the minimum set of fragments with available phenotypic attributes. Results obtained on seven e xperimental data sets made up of different plant species, number of individ uals per species' and number of markers, showed that the retrospective anal ysis did indeed find few relevant fragments (and markers) that best discrim inated the genotypes. In two data sets, the classification strategy of comb ining the information on the relevant minimum fragments with the available morpho-agronomic attributes produced compact and well-differentiated groups of genotypes.