Data from: Multiple aspects of the selfing syndrome of the morning glory Ipomoea lacunosa evolved in response to selection: a Qst-Fst comparison

The frequent transition from outcrossing to selfing in flowering plants is
often accompanied by changes in multiple aspects of floral morphology,
termed the “selfing syndrome.” While the repeated evolution of these
changes suggests a role for natural selection, genetic drift may also be
responsible. To determine whether selection or drift shaped different
aspects of the pollination syndrome and mating system in the highly
selfing morning glory Ipomoea lacunosa, we performed multivariate and
univariate Qst-Fst comparisons using a wide sample of populations of I.
lacunosa and its mixed-mating sister species I. cordatotriloba. The two
species differ in early growth, floral display, inflorescence, corolla
size, nectar, and pollen number. Our analyses support a role for natural
selection driving trait divergence, specifically in corolla size and
nectar traits, but not in early growth, display size, inflorescence size,
or pollen traits. We also find evidence of selection for reduced herkogamy
in I. lacunosa, consistent with selection driving both the transition in
mating system and the correlated floral changes. Our research demonstrates
that while some aspects of the selfing syndrome evolved in response to
selection, others likely evolved due to drift or correlated selection, and
the balance between these forces may vary across selfing species.