Abstract Detail

Pollination Biology

Fernando , Thilina R. [1], Herlihy, Christopher [1], Walck, Jeffrey [1].

Roles of local adaptation and pollinator selection in the maintenance of flower color polymorphism in Leavenworthia stylosa.

Flowering plants show an extraordinary diversity, especially in their reproductive structures.  Among floral traits, variation in flower color is the most noticeable one to the human eye and is a striking feature of many angiosperm species.  Once a color polymorphism has arisen in a population, it may be maintained either through adaptive processes like pollinator-mediated selection or through non-adaptive processes such as pleiotropic effects or genetic drift.  Our study species Leavenworthia stylosa, which is endemic to cedar glades in middle Tennessee, has two main flower color morphs: yellow and white, with most populations containing only one color.  The goal of this study was to determine if local adaptation to abiotic factors or differences in pollinator abundance or color preference play a role in maintaining the flower color polymorphism in this species.  We conducted a reciprocal transplant experiment by planting individuals from four populations into arrays of 100 plants alternating in flower color and source population.  Pollinator identity, abundance and preference were observed and plant survival and reproduction were recorded during the 2013 growing season.  Pollinators were also observed in two populations where both color morphs were present. We found variation in pollinator abundance among sites, and variation in the color preference of pollinators; however, this did not occur in a way that could maintain the flower color polymorphism. Overall, pollinators showed a 2:1 preference for white flowers in white, yellow, and mixed populations. Some pollinators observed showed assortative movement with respect to flower color: 80% of the transitions by butterflies, 54% of transitions by bee flies, and 46% of transitions by solitary bees were between white flowers. Both color morphs produced more flowers in their own color sites than in the other color sites. White plants had slightly reduced survival in yellow sites and the yellow plants had significantly reduced fruit production in white sites.  Thus, pollinator-mediated selection on flower color was not observed in these populations.  Although some evidence of local adaptation was found, it appears unlikely to play a strong role in the maintenance of the flower color polymorphism in L. stylosa.   

1 - Middle Tennessee State University, Biology, 1301 East Main st, P.O.Box 60, Murfreesboro, TN, 37132, USA

Keywords:
Leavenworthia
local adaption
pollinators.

Presentation Type: Poster:Posters for Topics
Session: P
Location: Eyrie/Boise Centre
Date: Monday, July 28th, 2014
Time: 5:30 PM
Number: PPL002
Abstract ID:281
Candidate for Awards:None