The present study aims at integrating the characterization studies conducted on the Cuban germplasm collection of Xanthosoma sagittifolium (Araceae) preserved in the Research Institute of Tropical Roots and Tubers Crops (INIVIT). Differentiation of accessions was done by combining qualitative and quantitative descriptors to clarify the relationships between six well-defined groups. The results may be used to establish a core collection for improved management of Xanthosoma spp. germplasm.

The present work was carried out on the basis of the previously obtained results where a total of 71 accessions of the Cuban cocoyam collection of the genus Xanthosoma in Cuba were used, which were characterized through the 24 minimum descriptors selected among those that included the number of chromosomes and the color of rhizome flesh. The isoenzyme systems esterases, peroxidases and polyphenol oxidases were also analyzed. The isoenzimatic bands associated with the present cytotypes and the color of rhizome flesh were determined through the CHAID method (Chi-squared Automatic Interaction Detector). The isoenzymatic bands and association them with the chromosome numbers and the color of rhizome flesh were selected from the decision trees obtained with the CHAID method, which allowed to build classification rules (logical expressions). This method has already been used successfully in the characterization of risk factors and diagnosis of diseases by other authors, but in the available literature there were not found references on its application in plants.From the practical point of view, having simple classification rules with high predictive value is very useful for in vitro early selection in genetic breeding programs, for in vitro conservation of germplasm to guide the collections of genetic material; in general, to detect early characteristics, such as the chromosome numbers and the color of rhizome flesh. They could also be used to detect interactions with predictive value, among other important characters on this and another genus. The created multiclassification rules allowed to achieve 100% of correct classification of the accessions according to the association of the isoenzymatic bands with the chromosome numbers and with the color of rhizome flesh, so they can be used as useful markers in the early determination of these characteristics.