title: Origin of year-long bean (Phaseolus dumosus Macfady, Fabaceae) from reticulated hybridization events between multiple Phaseolus species.
abstract: Background and Aims Improved understanding of the secondary gene pools of crops is essential for advancing genetic gain in breeding programmes. Common bean, Phaseolus vulgaris, is a staple crop with several wild relatives in its secondary gene pool. The year-long bean, P. dumosus, an important crop in Guatemala, is considered particularly closely related to P. vulgaris and a potential source of novel variation. However, the genetic diversity and relationship to other Phaseolus species of P. dumosus remain unclear. Methods We conducted the first comprehensive investigation of P. dumosus genetic diversity using both nuclear and chloroplast genome markers. Our nuclear marker set included over 700 markers present within the Phaseolus DArT (Diversity Arrays Technology) array, which we applied to P. dumosus and other relatives of P. vulgaris (including every secondary gene pool species: P. acutifolius, P. albescens, P. coccineus and P. costaricensis). Key Results Phaseolus dumosus arose from hybridization of P. vulgaris and P. coccineus, followed by at least two later hybridizations with sympatric congener populations. Existing P. dumosus collections have low genetic diversity. Conclusions The under-utilized crop P. dumosus has a complex hybrid origin. Further sampling in the region in which it arose may uncover additional germplasm for introgressing favourable traits into crops within the P. vulgaris gene pool.
authors: Genetics & Biotechnology Laboratory, Plant and AgriBiosciences Research Centre (PABC), Áras de Brún 2006, University Road, National University of Ireland Galway, Galway H91 REW4, Ireland.
authors: Angela M
authors: AM
authors: Mina-Vargas
authors: Genetics & Biotechnology Laboratory, Plant and AgriBiosciences Research Centre (PABC), Áras de Brún 2006, University Road, National University of Ireland Galway, Galway H91 REW4, Ireland.
authors: Peter C
authors: PC
authors: McKeown
authors: Pontificia Universidad Javeriana, Cali, Colombia.
authors: Nicola S
authors: NS
authors: Flanagan
authors: International Center for Tropical Agriculture (CIAT), Apartado Aéreo 6713, Cali, Colombia.
authors: Daniel G
authors: DG
authors: Debouck
authors: Diversity Arrays Technology Pty Ltd, Building 3, Level D, University of Canberra, Kirinari Street, Bruce, ACT 2617, Australia.
authors: Andrzej
authors: A
authors: Kilian
authors: Department of Botany, School of Natural Sciences, Trinity College Dublin, Dublin 2, Ireland.
authors: Trevor R
authors: TR
authors: Hodkinson
authors: Genetics & Biotechnology Laboratory, Plant and AgriBiosciences Research Centre (PABC), Áras de Brún 2006, University Road, National University of Ireland Galway, Galway H91 REW4, Ireland.
authors: Charles
authors: C
authors: Spillane
keywords: 
            Phaseolus dumosus
          ; common bean; crop wild relative (CWR); genetic diversity; hybridization; inter-species; reticulate evolution; secondary gene pool; sympatry; year-long bean