Origins of determinate growth habit in Phaseolus

One of the traits that appeared during domestication of common bean, Phaseolus vulgaris, is determinacy, in which stems end with a terminal inflorescence. Kwak et al. examine sequence variation in PvTFL1y, the gene that underlies determinancy, in 46 wild and domesticated accessions that include both the determinate and indeterminate growth habits. They find that all indeterminate types show only synonymous nucleotide substitutions whereas determinate types – observed only among domesticated accessions – show several additional mutation types that potentially cause reduction or elimination of gene expression. Although each of the determinacy haplotypes probably does not represent distinct domestication events, they are consistent with the multiple domestication pattern in the genus Phaseolus.