Morphological and nucleotide diversity in wild and cultivated common bean (Phaseolus vulgaris L.) accessions from different genepools.

To identify and characterize the genes responsible for phenotypic variation is an essential goal for geneticists and breeders. This study examined the organisation of diversity for morphological and molecular markers in a sample of 101 inbred genotypes of Phaseolus vulgaris L and 5 genotypes of P. coccineus and P. lunatus, used as controls. The sample has been obtained to represent the evolutionary history of common: wild and domesticated forms from Mesoamerican and Andean gene pools were included. The 106 genotype include: 11 wild Mesoamerican genotypes; 28 domesticated Mesoamerican genotypes (from Mexico and Central America); 29 wild Andean genotypes; 33 domesticated Andean genotypes (from South America); 5 genotypes of P. coccineus and P. lunatus. The differences among and within common bean accessions were initially studied using a set of 29 phenotypic descriptors (14 qualitative traits and 15 quantitative traits). All data were analysed by uni and multivariate statistical analysis. Variation among nucleotides sequenced at 2 loci was also investigated. A total of 924 bp of aligned sequence for each genotype were analysed. Collectively, the sequences of all genotypes defined 17 haplotypes, Andean genotypes showed the highest number of haplotypes. The number of indel polymorphism was of 19. Nucleotide diversity ranged from 0,0024 !/bp to 0,047 !/bp. Negative Tajima D values was found in Mesoamerican wild genotypes (-1,6508). No reduction of diversity was observed in domesticated germplasm compared to the wild genepool.