Prebreeding in Common Bean and Use of Genetic Diversity from Wild Germplasm

Abstract

ABSTRACTCommon bean (Phaseolus vulgaris L.) is the most widely consumed grain legume in the world. This cultigen was domesticated from wild P. vulgaris, an indeterminate viny plant, distributed from Mexico to Argentina in midaltitude neotropical and subtropical regions. To colonize such diverse ecological niches, the species possesses many adaptation traits and a wealth of genetic diversity. However, breeding programs are limited by the under‐utilization of the available genetic diversity because of the necessity of prebreeding exotic material. Due to partial reproductive isolation between the domesticated Andean and Mesoamerican gene pools, hybridizations between wild and domesticated types of P. vulgaris from the same gene pool offer greater potential to enhance the variation in the crop. Evaluations of wild P. vulgaris accessions have shown resistance to insects and diseases and higher N, Fe, and Ca content in seeds, which will ultimately contribute to improvements in nutritional quality and yield. Recurrent and inbred backcross methods are being used for the transfer of both qualitative and quantitative traits from wild into domesticated forms of P. vulgaris; specific data on yield and 100‐seed weight are presented. The prebreeding efforts will be enhanced by (i) information on gene pool origins, domestication syndrome traits, molecular diversity, and mapping data of the wild forms; (ii) indirect screening for biotic and abiotic stresses; and (iii) marker‐assisted selection.