Abstract Detail

Reproductive biology

Dudle, Dana A. [1], Davis, Sandra L. [2], Ritke, Mary K. [2].

Why does bouncing bet blush? Heritability and plasticity of floral color and anthocyanidin synthase expression in Saponaria officinalis.

Saponaria officinalis (bouncing bet) produces flowers that change color from white to pink as they transition between staminate and pistillate phase. Our previous work demonstrated that the extent of this color change depends on a plant’s exposure to sunlight, such that shaded plants produce paler flowers than those in full sun. Furthermore, diurnal insect pollinators visit white or pale flowers more often than pink flowers in experimental arrays, indicating a potential fitness disadvantage associated with pinkness. Here, we asked whether there is heritable genetic variation of floral color among different clonal genotypes of S. officinalis. We grew replicates of eight clonal genotypes in two common-garden environments (sun and 60% shade) in the summer of 2013. We quantified floral size, shape, and color of staminate- and pistillate-phase flowers, as well as vegetative characters of these genotypes in both environments. We also hypothesized that increased pigmentation in pistillate-phase flowers compared to staminate-phase flowers, and the degree of pinkness in different clonal genotypes would parallel the levels of anthocyanidin synthase (ANS) expressed in petals, as quanitified by qPCR. Our results indicate significant and substantial heritable variation in floral color among our clones. In addition, some clonal genotypes exhibit greater plasticity of floral color than others in response to changes in sun exposure. We also found that ANS expression appears to vary between staminate and pistillate phases, and among clonal genotypes. These results indicate that natural selection should be able to act on the variation in floral color to cause change in populations of S. officinalis and that there may be additional selective factors maintaining variation in pink coloration that counter the negative selection imposed by diurnal pollinators.

1 - Depauw University, Department Of Biology, 114 Olin Hall Of Biological Sciences, 1 E. Hanna Street, Greencastle, IN, 46135, USA
2 - University Of Indianapolis, Department Of Biology, 1400 E. Hanna Ave., Indianapolis, IN, 46227, USA

Keywords:
Anthocyanin
Flower color polymorphism
Caryophyllaceae
Saponaria officinalis.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PRP003
Abstract ID:404
Candidate for Awards:None