Random amplified polymorphic DNA (RAPD) markers variability among cultivars and landraces of common beans (Phaseolus vulgaris L.) of south-Brazil

To evaluate the variability among cultivars and landraces of common bean (Phaseolus vulgaris L.), 15 cultivars and 18 landraces of common bean (Phaseolus vulgaris L.), a undefined species of Phaseolus, two landraces of Vigna angularis L., and a landrace of soybean (Glycine max L.), were screened with fifteen oligonucleotide primers in PCR reactions. An average of 20.3 RAPD bands were scored per primer. A total of 304 amplification products were scored of which 88.8% were polymorphic among Phaseolus genotypes. Based on the RAPD markers, four major clusters were formed. Three clusters corresponded to the soybean, to the two Vigna angularis landraces, and to the Phaseolus sp. landrace, respectively. The fourth cluster include all the landraces and cultivars of Phaseolus vulgaris. This large group could be separated into three subgroups that were correlated with the phaseolin patterns and the average seed weight of the genotypes. The analysis shows that most of the landraces collected in South Brazil (17 out of 18) belong to the Andean gene pool, and most of the cultivars (13 out of 15) belong to the Middle American gene pool.