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
Although the evolution of the selfing syndrome often involves reductions in floral size, pollen and nectar, few studies of selfing syndrome divergence have examined nectar. We investigate whether nectar traits have evolved independently of other floral size traits in the selfing syndrome, whether nectar traits diverged due to drift or selection, and the extent to which quantitative trait locus (QTL) analyses predict genetic correlations. We use F5 recombinant inbred lines (RILs) generated from a cross between Nectar and floral size traits form separate evolutionary modules. Selection has acted to reduce nectar traits in the selfing Changes in floral traits associated with the selfing syndrome reflect independent evolution of at least two evolutionary modules: nectar and floral size traits. We also demonstrate directional selection on nectar traits, which is likely to be independent of selection on floral size traits. Our study also supports the expected mechanistic link between QTL properties and genetic correlations.
- Publication Date:
- NSF-PAR ID:
- 10361277
- Journal Name:
- New Phytologist
- Volume:
- 233
- Issue:
- 3
- Page Range or eLocation-ID:
- p. 1505-1519
- ISSN:
- 0028-646X
- Publisher:
- Wiley-Blackwell
- Sponsoring Org:
- National Science Foundation
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