An international consortium called `Phaseomics' is formed to establish the necessary framework of knowledge and materials that will result in disease-resistant, stress-tolerant, high-quality protein and high-yielding beans, which will be instrumental in improving living conditions in deprived regions of Africa and the Americas.
2 independent domestications from genetic pools that diverged before human colonization are confirmed and a set of genes linked with increased leaf and seed size are identified and combined with quantitative trait locus data from Mesoamerican cultivars.
Multivariate statistical analyses of morphological, agronomic, and molecular data, as well as other available information on Latin American landraces representing various geographical and ecological regions of their primary centers of domestications in the Americas, reveal the existence of two major groups of germplasm: Middle American and Andean South American, which could be further divided into six races.
A total of 150 microsatellite markers developed for common bean were tested for parental polymorphism and used to determine the positions of 100 genetic loci on an integrated genetic map of the species, finding gene-coding microsatellites proved to be less polymorphic than anonymous genomic microSatellites between the parents of two inter-genepool crosses.
The Andean domesticated race Nueva Granada had the highest FST value and widest geographic distribution compared to other domesticated races, suggesting a very recent origin or a selection event, presumably associated with a determinate growth habit, which predominates in this race.
The authors' data favor 2 primary areas of domestication, one in Middle America leading to small-seeded cultivars with ‘S’ phaseolin patterns and the other in the Andes giving rise to large-seeding cultivarsWith ‘T’ (and possibly ‘C,’ ‘H,” and ‘A’) phaseolinpatterns.
The results suggest that domestication of common bean could have proceeded rapidly and that evolution can proceed through changes involving a few genes with large effect rather than through a gradual accumulation of changes coded by changes with small effects, and that adaptation to rapidly changing environmental conditions may involve genes withLarge phenotypic effects.
The first successful assignment of 15 microsatellite or simple sequence repeat (SSR) markers to the Phaseolus vulgaris molecular linkage map is reported, indicating a widespread distribution throughout the bean genome.
Confirmation that cultivated common bean (Phaseolus vulgaris L.) resulted from multiple domestications in Mesoamerica and in Andean South America was sought by analyzing patterns of diversity at nine polymorphic allozyme loci, all unlinked to the phaseolin locus.