Common bean genomics and its applications in breeding programs

Abstract

Because of its nutritional value, easiness of cultivation, and cultural preference in many cases, common bean (Phaseolus vulgaris L.) is the most important grain legume in the human diet worldwide. Recent genomic evidence suggest that common bean originated in Central America and confirms the two centers of domestication previously characterized (Mesoamerican and Andean), with well-defined races within each gene pool. Total world production of dry bean from the 10 year period 1961-1970 increased 65 % to 169 million MT in the period 2001-2010. The main challenge now is how to apply these genomic tools into breeding programs for increased efficiency. Applications go from marker-assisted breeding to tracking of F 1 crosses, and even DNA fingerprinting, among others. More recently, the development of thousands of single nucleotide polymorphisms (SNP) markers and the completion of the bean genome sequence have opened numerous opportunities for fine mapping and gene characterization. The exploitation of linkage disequilibrium through association mapping allows for rapid identification of important genomic regions associated with traits of economic importance without the need of creating bi-parental populations for this goal. The following sections will describe specific examples of applications of these genomic tools into breeding programs and illustrate some of the possible future directions some of these technologies may follow.