Suitability of AFLP markers for the study of genomic relationships within the Oxalis tuberosa alliance

O. tuberosa is an Andean crop that belongs to the worldwide distributed genus Oxalis. On the basis of their chromosome numbers the following species (O. herrerae, O. lotoides, O. medicaginea, O. mollissima, O. oblongiformis, O. peduncularis, O. spiralis, O. subintegra, O. tabaconanensis, O. tubersoa, O. villosula) were placed in an alliance. To analyse five species belonging to the Oxalis tuberosa alliance (O. oblongiformis, O. peduncularis, O. tabaconanensis O. tuberosa and O. villosula) and a distant member of the genus (O. articulata), we examined 253 AFLP markers generated after amplification using four primer combinations. Within the alliance, two main clusters were observed, one containing the diploid species and the other group with the polyploid species O. tuberosa. All of the primer combinations assayed showed the same clustering pattern. Grouping of accessions of each species by data analysis corresponded largely with their previous taxonomic classifications. The concordance between the clustering of the individuals belonging to different species obtained in this work show the appropriateness of AFLP markers for this type of study. The results obtained are in good agreement with the cytogenetic hypothesis and showed a clustering behaviour, which is similar to the one previously obtained using ITS rDNA nucleotide sequence comparison.