Genepool of a year-long bean crop, Phaseolus dumosus

Studying the relationships between major crops and the secondary genepools of related species that are more resistant to climate challenges, Mina-Vargas et al. employ nuclear and chloroplast genetic markers to carry out a comprehensive investigation of the genetic diversity of a year-long staple Guatamalan legume crop.

Hybridization network showing the hypothetical reticulation events among Phaseolus species. — Hybridization network showing the hypothetical reticulation events among *Phaseolus* species. The network was generated from a 60 % BS consensus tree of ML analyses for sequences of cpDNA and ITS; reticulations derived from the chloroplast genome are indicated by green lines and reticulations from the nuclear genome by orange lines; strong lines indicate reticulations between species and fine lines indicate reticulations within species (accession names have been omitted for clarity).

They find that the common bean, Phaseolus dumosus, which has high levels of stress resistance, is closely related to its wild relatives P. coccineus and P. vulgaris, and arose from recent hybridizations between them. Further to analysing all collected specimens of P. dumosus, the authors conclude that this species seems to have lower genetic diversity than its relatives. They also identify regions where diverse populations with additional germplasm of potential value for introgressing favourable traits into other crops within the P. vulgaris genepool might still remain to be uncovered.