The timing of molecular and morphological changes underlying reproductive transitions in wild tomatoes (Solanum sect. Lycopersicon)

Molecular mechanisms underlying the transition from genetic self-incompatibility to self-compatibility are well documented, but the evolution of other reproductive trait changes that accompany shifts in reproductive strategy (mating system) remain comparatively poorly understood. A notable exception is the transition from exserted styles to styles with recessed positions relative to the anthers in wild tomatoes (Solanum Section Lycopersicon). This phenotypic change has been previously attributed to specific mutation in the promoter of a gene that influences style length (style2.1); however, whether this specific regulatory mutation arose concurrently with the transition from long- to short-styles, and whether it is causally responsible for this phenotypic transition, has been poorly investigated across this group. To address this gap, we assessed 74 accessions (populations) from 13 species for quantitative genetic variation in floral and reproductive traits as well as the presence/abse...