2012 Annual Report 1a.Objectives (from AD-416): To evaluate, characterize, and improve common bean genetics for biological nitrogen fixation. 1b.Approach (from AD-416): ARS will acquire germplasm, conduct field studies, and perform genetic analysis; WSU will provide graduate student support and expertise on characterization of soils and rhizobium strains. 3.Progress Report: Fifty-one lines were analyzed for biological nitrogen fixation (BNF) under field conditions and greenhouse conditions in Fall 2011. Progress was made toward sub-objective 1B of the related in-house project, "Develop dry bean germplasm with enhanced disease and/or abiotic stress resistance using MAS in combination with traditional breeding approaches", as a few lines with enhanced biological nitrogen fixation were identified. Data suggests variation for BNF among the lines tested. Parents with low and high BNF were selected for crossing to generate segregating populations for genetic analysis of BNF efficiency in common bean. Ten hybridizations were successfully generated in Spring 2012. The 51 lines were planted again in the field in 2012 to examine line by environment interactions for BNF.