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Abstract Detail



Ecological Section

Fernando, Thilina [1], Herlihy, Christopher R. [2], Walck, Jeffrey [3].

Roles of local adaptation and stress tolerance at early life history stages in the maintenance of flower color polymorphism in Leavenworthia stylosa.

Many plant species exhibit conspicuous variation in flower color among individuals as well as among sites in different parts of their range. This variation is generally attributed to differences in pollinators and their color preference. However, several lines of evidence suggest that local adaptation or drought tolerance may also maintain flower color polymorphisms. Our study species Leavenworthia stylosa, is endemic to cedar glades in middle Tennessee and has two main flower color morphs: yellow and white, with most populations containing only one color. Our previous studies suggested that the variation and preference of local pollinators do not explain the flower color distribution pattern of the species. The goal of this study was to determine the role of local adaptation and stress tolerance of the two color morphs at the seed germination and seedling stages. We conducted two reciprocal transplant experiments: one with seeds and the second with seedlings in Fall 2014 and winter 2014, respectively, with four source populations and four transplant sites. In addition, seed dormancy break of the two color morphs was studied with six populations under four watering regimes and seed germination was investigated under an osmotic pressure gradient with seeds from four populations. White seeds had slightly higher germination in white sites. Seed dormancy break of the yellow morph differed significantly (t test, P<0.05) from the white morph in a constant wet treatment. There was no difference in germination of the two morphs at among osmotic pressures, with the exception of minor germination from both white populations compared to none from yellow at -1.0 MPa. Rosettes from all the source populations showed a slightly higher survival during winter in the yellow transplant sites compared to white sites. However, one yellow population had 100% survival in all transplant sites and all source populations showed a slightly higher survival up to the reproductive stage in yellow transplant sites. Thus, we did not find evidence for local adaptation of color morphs at the seed germination and seedling stages. The different germination responses of the two morphs under constant wetness suggest that some aspect of water saturation may be involved in the maintenance of flower color polymorphism in Leavenworthia stylosa.


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1 - Middle Tennessee State University, Biology, P.O. Box 60 , Murfreesboro, TN, 37130, USA
2 - Middle Tennessee State University, Department Of Biology, 1301 E Main St, PO Box 60, Murfreesboro, TN, 37132, USA
3 - Middle Tennessee State University, 1301 East Main St, PO Box 60, Murfreesboro, TN, 37132, USA

Keywords:
Flower color polymorphism
local adaptation
osmotic stress
drought stress.

Presentation Type: Poster:Posters for Sections
Session: P
Location: Hall D/The Shaw Conference Centre
Date: Monday, July 27th, 2015
Time: 5:30 PM
Number: PEC017
Abstract ID:139
Candidate for Awards:None


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