Abstract Detail

Hybrids and Hybridization

Stevens, Josh [1], Wessinger, Carolyn [2].

Pollination syndrome variation in a Penstemon hybrid zone.

Penstemon is a large genus of perennial wildflowers spanning most of North America. This group has experienced at least 20 independent transitions from bee to hummingbird pollinated flowers. Ancestral bee pollinated flowers display wide blue or purple flowers with a landing platform for pollinators. In contrast, hummingbird syndrome flowers have long red corollas and produce a larger volume of nectar. Natural hybridization events between species that differ in pollinator provide the opportunity to investigate the genetic basis for pollination syndrome divergence and the fitness effects of intermediate floral syndromes. P. laevis (bee) and P. eatonii (hummingbird) are sister species that occur in the intermountain west and form natural hybrid zones where they overlap in distribution near the Utah/Arizona border. Here we quantify variation in floral traits (floral shape, color, and nectar production) within a large natural hybrid population. We find that hybrids show flower color variation that represents variation in both hue and intensity. This variation in flower color is explained by variation in anthocyanin pigment production. We find correlations between several key pollination syndrome traits which may be due to correlated patterns of ancestry and/or linkage among traits. We discuss our findings in light of findings from a related species pair where divergence in floral pollination syndrome has a simple genetic architecture involving few large effect loci.

1 - University of South Carolina, Biology, 8 Jay Dr , Rindge, NH, 03461, USA
2 - 1010 Henderson St, Columbia, SC, 29201, United States

Keywords:
Penstemon
hybridization
Pollination syndromes.

Presentation Type: Poster
Number: PHH003
Abstract ID:490
Candidate for Awards:None