Abstract Detail

Evolution, Development, and BSA Genetics of Floral Display - Form, Size, and Arrangement

Hileman, Lena C [1].

Phylogenetic and genetic patterns of flower evolution in Penstemon.

Parallel evolution suggests that certain phenotypic transitions are repeatedly favored and can be readily generated through recurrent mutation. The wildflower genus Penstemon exhibits a dynamic history of flower evolution. Hummingbird adapted flowers have evolved multiple times within bee adapted lineages. Our phylogenetic results suggests that the transition rate from bee to hummingbird adapted flowers is higher than the transition rate in the reverse direction. A higher rate of diversification in bee adapted lineages can explain a stable equilibrium of species with bee adapted flowers in Penstemon. Our characterization of the genetic architecture of hummingbird adaptation in one species pair suggests that few mutations of large effect may spur the initial shift in floral traits. We also find that individual loci may pleiotropically influence multiple floral phenotypes, which may accelerate evolutionary shifts to hummingbird pollination. Our broader goal is to leverage Penstemon as a model system to explore microevolutionary processes that shape trait diversity at a macroevolutionary scale. We are undertaking comparative developmental and QTL mapping studies to determine whether independent origins of hummingbird adapted floral traits arise from parallel genetic changes. As described above, our preliminary evidence suggests that hummingbird adapted flowers represent phenotypic end points from which transitions back to bee adapted flowers are evolutionarily constrained. We will identify ecological and genetic constrains that shape this transition rate asymmetry. For example, we are testing whether conditional selection on individual floral traits, or loss-of-function mutations underlying hummingbird adapted traits, limits the rate of transition from hummingbird to bee adapted flowers.

1 - University Of Kansas, 1200 Sunnyside Avenue, Lawrence, KS, 66045, USA

Keywords:
floral evolution
parallelism
phylogenomics
RADseq
quantitative genetics.

Presentation Type: Symposium Presentation
Session: SY05, Evolution, Development, and Genetics of Floral Display - Form, Size, and Arrangement
Location: Chatham Ballroom - B/Savannah International Trade and Convention Center
Date: Tuesday, August 2nd, 2016
Time: 9:15 AM
Number: SY05004
Abstract ID:174
Candidate for Awards:None