Selection for increased percentage phaseolin in common bean

Summary Two selection methods were compared to determine which was more efficient for increasing percentage phaseolin in the common bean (Phaseolus vulgaris L.). A base population consisting of families segregating for six seed protein alleles (Phas^S, Phas^C, Phas^T, phas^-, lec^-, and Arcl⁺), all of which have measurable effects on percentage phaseolin, was subjected to either three cycles of S₁ family recurrent selection for increased percentage phaseolin (PPS), or one cycle of selection for combinations of the protein alleles (PAS) known to have positive effects on phaseolin accumulation. One cycle of PAS resulted in an increase in percentage phaseolin that was equivalent to three cycles of PPS. Selection under both methods produced increases in several correlated traits including percentage total protein, phaseolin as a percent of total protein, mg protein/seed, and mg phaseolin/seed. The amount of nonphaseolin protein per seed decreased, while seed yield was unaffected by either selection procedure. By selecting for favorable seed protein alleles identified by electrophoresis, it was possible to rapidly increase percentage phaseolin without the need for field evaluation.