Evolution of genetic diversity during the domestication of common-bean (Phaseolus vulgaris L.)

Abstract

M13 DNA fingerprinting was used to determine evolutionary changes that occurred in Latin American germ plasm and USA cultivars of commonbean (Phaseolus vulgaris L.) during domestication. Linkage mapping experiments showed that M13-related sequences in the common-bean genome were either located at the distal ends of linkage groups or that they were unlinked to each other or to any previously mapped markers. Levels of polymorphism observed by hybridization with M13 (1 probe-enzyme combination) were comparable to those observed by hybridization with single-copy random PstI genomic probes (36 enzyme-probe combinations) but were higher than those observed for isozymes (10 loci). Results indicated that the wild ancestor had diverged into two taxa, one distributed in Middle America (Mexico, Central America, and Colombia) and the other in the Andes (Peru and Argentina); they also suggested separate domestications in the two areas leading to two cultivated gene pools. Domestication in both areas led to pronounced reductions in diversity in cultivated descendants in Middle America and the Andes. The marked lack of polymorphism within commercial classes of USA cultivars suggests that the dispersal of cultivars from the centers of origin and subsequent breeding of improved cultivars led to high levels of genetic uniformity. To our knowledge, this is the first crop for which this reduction in diversity has been documented with a single type of marker in lineages that span the evolution between wild ancestor and advanced cultivars.

Microsatellite characterization of Andean races of common bean (Phaseolus vulgaris L.)

“…This point is important given the lack of evidence for a separate domestication leading to race Chile and the incongruence that this race may have arisen separately even though it has not been associated with specific wild accessions (Debouck et al 1993;Johns et al 1997;Chacón et al 2005). Our results may indicate that race Chile precursors moved from the primary center of origin in Northwestern Argentina across the Andes mountains into temperate latitudes in central Chile, a hypothesis that would be supported by results from Sonnante et al (1994) showing close relationship of race Chile genotypes with Argentine wild accessions. This would require additional study using wild accessions to determine if the some contribute to race Chile and are distinct from those wild beans contributing to races Nueva Granada and Peru that are thought to be in the primary center of origin especially in Bolivia and Southern Peru (Beebe et al 2001).…”

A single domestication for maize shown by multilocus microsatellite genotyping

“…The estimated number of generations ( ) was converted into years by assuming 1 year equals 1 generation. Ten thousand bootstrap samples for (␦ ) 2 were computed to estimate 95% confidence limits for the time of divergence.…”

Investigation of the domestication of common bean (Phaseolus vulgaris) using multilocus sequence data

“…Two large gene pools of wild types were identified based on phaseolin seed protein variation Gepts 1990), DNA marker diversity (Becerra Velasquez and Gepts 1994;Sonnante et al 1994;Freyre et al 1996;Tohme et al 1996), morphology (Evans 1976;Gepts and Debouck 1991), isozymes (Koenig and Gepts 1989), mitochondrial DNA variation (Khairallah et al 1992) and amplified fragment length polymorphism (AFLP) (Rossi et al 2009) and short sequence repeats (SSR) ) marker data.…”