Wild beans (Phaseolus L.) of North America

Authors: DOHLE, SARAH - Delaware Valley College; BERNY MIER Y TERAN, JORGE - University Of California, Davis; EGAN, ASHLEY - Smithsonian Institute; Kisha, Theodore; Khoury, Colin

Submitted to: Book Chapter
Publication Type: Book / Chapter
Publication Acceptance Date: 11/25/2017
Publication Date: 4/2/2019
Citation: Dohle, S., Berny Mier Y Teran, J.C., Egan, A.N., Kisha, T.J., Khoury, C.K. 2019. Wild beans (Phaseolus L.) of North America. Book Chapter. https://doi.org/10.1007/978-3-319-97121-6_4.
DOI: https://doi.org/10.1007/978-3-319-97121-6_4

Interpretive Summary: The wild relatives of the five domesticated species of bean (Phaseolus L.) are widely distributed across the tropics and subtropics of the New World, with taxa extending to the Canadian border, the Caribbean islands and Bermuda, the Galapagos Islands, and south to Argentina. Mesoamerica holds the largest concentration of species, particularly in the highlands of central Mexico, northward along the Sierra Madre Occidental, and south to Chiapas. The progenitors and close relatives of all five domesticates are also concentrated in this region. Plant breeding involving the use of wild relatives has almost entirely been directed toward the improvement of common bean (Phaseolus vulgaris L.), the most widely cultivated species, and successful contributions have mostly come from its progenitor (Phaseolus vulgaris L. var. aborigineus [Burkart] Baudet) and a few other taxa. Wild taxa are considered to possess novel useful genetic variation that has not yet been fully explored. A number of wild Phaseolus are rare endemics that are threatened in their natural habitats, and are insufficiently protected in situ. Significant ex situ collections of wild Phaseolus are maintained at the International Center for Tropical Agriculture (CIAT), the USDA-ARS National Plant Germplasm System, within the Sistema Nacional de Recursos Fitogenéticos para la Alimentación y la Agricultura (SINAREFI) Conservation Centers Network in Mexico, and at the Botanic Garden Meise, Belgium. Unfortunately, over 26% of Phaseolus taxa are not represented at all in these ex situ conservation facilities, and another 28% are represented by less than 10 accessions, making over half of the species highly under-represented in genebanks. Enhanced protection of vulnerable species in their natural habitats, and further collecting to fill critical gaps in germplasm collections are highly warranted.

Technical Abstract: The wild relatives of the five domesticated species of bean (Phaseolus L.) are widely distributed across the tropics and subtropics of the New World, with taxa extending to the Canadian border, the Caribbean islands and Bermuda, the Galapagos Islands, and south to Argentina. Mesoamerica holds the largest concentration of species, particularly in the highlands of central Mexico, northward along the Sierra Madre Occidental, and south to Chiapas. The progenitors and close relatives of all five domesticates are also concentrated in this region. Plant breeding involving the use of wild relatives has almost entirely been directed toward the improvement of common bean (Phaseolus vulgaris L.), the most widely cultivated species, and successful contributions have mostly come from its progenitor (Phaseolus vulgaris L. var. aborigineus [Burkart] Baudet) and a few other taxa. Wild taxa are considered to possess novel useful genetic variation that has not yet been fully explored. A number of wild Phaseolus are rare endemics that are threatened in their natural habitats, and are insufficiently protected in situ. Significant ex situ collections of wild Phaseolus are maintained at the International Center for Tropical Agriculture (CIAT), the USDA-ARS National Plant Germplasm System, within the Sistema Nacional de Recursos Fitogenéticos para la Alimentación y la Agricultura (SINAREFI) Conservation Centers Network in Mexico, and at the Botanic Garden Meise, Belgium. Unfortunately, over 26% of Phaseolus taxa are not represented at all in these ex situ conservation facilities, and another 28% are represented by less than 10 accessions, making over half of the species highly under-represented in genebanks. Enhanced protection of vulnerable species in their natural habitats, and further collecting to fill critical gaps in germplasm collections are highly warranted.