Oligonucleotide DNA fingerprinting revealing polymorphism in Phaseolus lunatus L.

Digoxigenated synthetic oligonucleotides complementary to simple repetitive DNA sequences were used to detect polymorphisms in Phaseolus lunatus L. (Lima bean) genotypes. Twenty two accessions, including wild and cultivated representatives of the Mesoamerican and Andean gene pools and intermediate forms were included in this study. It could be shownthat five repetitive motifs, namely (AAT)5,(ATG)5,(GACA)4,(GATA)4,(GGAT)4, were able to give clear-cut bands when used as probes and to reveal high levels of variation. The highest resolving power was revealed by the(AAT)5 probe, which was able to detect even inter-individual polymorphisms. Therefore, oligonucleotide fingerprinting has proved to be a useful tool to analyse geneticdiversity in Lima bean. Phylogenetic reconstruction based on JACCARD's similarity index confirmed the existence of two major gene pools and the presence of a minor group of genetically separated intermediate genotypes.