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Abstract Detail

Physiological Section

Jordon-Thaden, Ingrid [1], Facio Viccini, Lyderson [2], Combs , Joseph Anthony [1], Chester, Michael [1], Soltis, Douglas [1], Soltis, Pamela [3].

Physiological comparisons of two recently formed allotetraploid Tragopogon(Asteraceae) species and their diploid parents.

This study seeks to understand how polyploidy affects phenotypic variation in natural and synthetic allotetraploids (Tragopogon mirus and Tragopogon miscellus) through comparison with their diploid parents (T. dubius, T. pratensis, and T. porrifolius). This system is ideal to study speciation processes, due to the recent formation of these two polyploids. Easily definable phenotypic characteristics, such as plant height (cm), total leaf number, and photosynthetic efficiency, were measured and will be correlatedto genetic data from the same set of plants in a parallel study. Tragopogon plants (diploid and tetraploid) were placed in a temperature and light controlled growth chamber in randomized blocks. Over a period of a month, several discrete growth measurements were taken. Growth rate data were taken by measuring the longest leaf on a given plant and the number of healthy, green leaves on the plant. Over a period of two weeks, the physiological potential for photosynthesis of each plant was taken with a fluorometer to determine the photosynthetic efficiency of photosystem II. The synthetic and natural allotetraploids appear to have similar growth rates and photosynthetic capacity. The allotetraploids compared to their diploid parents reach maximum height quicker and are more photosynthetically efficient. When compared by maximum leaf growth, the allotetraploids T. miscellus and T. mirus exhibit a growth pattern comparable to that of the diploid parent T.pratensis or T. porrifolius, respectively, and are divergent from their shared T.dubius parent. These results suggest that allotetraploid species are more robust and vigorous in certain phenotypic traits, such as the ability to perform photosynthesis, than their parents, but in other physical characteristics the allotetraploids tend to exhibit characteristics of a single parent.

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1 - University of Florida, Department of Biology, Gainesville, FL, 32611, USA
2 - Instituto de Ciências Biológicas, Universidade Federal de Juiz de Fora, Departmento de Biologia, Juiz de Fora, Minas Gerais, 36036-900, Brazil
3 - University Of Florida, Florida Museum Of Natural History, PO BOX 117800, Gainesville, FL, 32611-7800, USA

phenotypic variation

Presentation Type: Poster:Posters for Sections
Session: P
Location: Khorassan Ballroom/Chase Park Plaza
Date: Monday, July 11th, 2011
Time: 5:30 PM
Number: PPS008
Abstract ID:547

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