Recent Topics Posters
Carlson, Matthew , Abdelaziz, Mohamed , Barsis, Josh , Butler, Tim , Dick, Cindy , Fulkerson, Justin , Hamilton, Savannah , Hess, Cara , Munsen, Rachel , Portilla, Mimi , Schneider, Keith , Schneller, Laura , Storelli, Beth , Kliebenstein, Dan , Whittall, Justen B. .
Exceptional flower color diversity in the Arctic: The roles of pollinator and non-pollinator agents of selection on Parrya nudicaulis (Brassicaceae).
The Arctic presents a unique suite of selective pressures that should result in limited intraspecific variation. Counter to this expectation, the Arctic mustard, Parrya nudicaulis, exhibits exceptional diversity in flower color. For flower color in particular, a trend toward increasing frequency of purple individuals with decreasing growing degree-days suggests a role for natural selection against white morphs in shorter growing seasons. Opposing selective pressures by pollinators and non-pollinator agents, such as cold temperatures and herbivores, could maintain this flower color variation. Traits that increase the temperature of reproductive organs, such as floral pigmentation, may increase developmental rates and/or provide thermal rewards to pollinators selecting for increased pigmentation in colder climates. We examined the temperature differences between ambient and petal tissue and ambient and ovary tissue across a gradient of floral pigmentation types. Alternatively, herbivores, which are reported to prefer less pigmented individuals in other mustards, may also help maintain variation in flower color. Therefore, we compared levels of herbivory, trichome density and glucosinolate production across the same gradient of floral pigmentation types. These results are interpreted in light of pollinator preferences for different color morphs. Variation in floral traits of Arctic plants could result from opposing selective pressures that may be more common than previously appreciated.
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1 - University of Alaska, Biological Sciences Department, Anchorage, AK, 99501, USA
2 - University of Granada, Department of Genetics, Granada, 18071, Spain
3 - Santa Clara Unviersity, Biology Department, 500 El Camino Real, Santa Clara, CA, 95053, USA
4 - Santa Clara Unviersity, Biology Department, 500 El Camino Real
5 - University of California, Department of Plant Sciences, One Shields Ave., Davis, CA, 95616, USA
6 - Santa Clara University, Biology Department, 500 El Camino Real, Santa Clara, CA, 95053, USA
Presentation Type: Recent Topics Poster
Location: Event Tent/Cliff Lodge
Date: Tuesday, July 28th, 2009
Time: 5:30 PM