Morphological and molecular diversity of Swiss common bean cultivars (Phaseolus vulgaris L., Fabaceae) and their origin

We investigated morphological and molecular diversity within cultivated com mon bean (Phaseolus vulgaris L.) in Switzerland and examined the origin of Swiss cultivars. We considered commercially traded cultivars and elder cult ivars. These elder cultivars, often called landraces, collected and kept on farm by the Swiss non-governmental organisation Pro Specie Rara, are suppo sed to represent an endangered heritage of diversity within common bean. Mo rphological characters, phaseolin Sodium Dodecyl Sulfate Polyacrylamid gel- electrophoresis (SDS-PAGE), isoenzymes, and banding patterns of Random Ampl ified Polymorphic DNA (RAPD) showed polymorphisms and diversity among Swiss common bean cultivars. Cultivars were characterised either by the S-type o r the T-type of the major storage protein phaseolin. This indicates that so me Swiss cultivars have Mesoamerican origin while others have Andean origin . This hypothesis is corroborated by the Unweighted Pair Group Measured Ana lysis (UPGMA) clustering of the cultivars with a combined set of morphologi cal, phaseolin, isoenzyme and RAPD data. A better knowledge of genetic and phenotypic aspects of the common bean helps to improve conservation program s for its endangered cultivars.