Abstract Detail

Crops and Wild Relatives

Davis, Rebekah [1], Mason, Chase [2], Goolsby, Eric [3].

Phylogenetic comparative assessment of light response curve evolution in wild sunflowers (Helianthus): a function-valued trait approach.

Photosynthetic variation is driven by genetic differences as well as plastic variation in response to environmental variables. Gas exchange measurements can be taken at a single time point, or at multiple points while modifying a continuous environmental variable. Light response curves describe photosynthetic variation as a function of light intensity, and plant traits such as maximum photosynthetic rate, light compensation point, and quantum yield can be extracted. In addition to extracting univariate summary metrics from light response curves, the entire curve itself can also be thought of as a trait, or more specifically, a function-valued trait. While the study of univariate physiological traits provides valuable phenotypic information, key variation is often discarded with these summary metrics, whereas the study of function-valued traits attempts to capture a more comprehensive picture of trait variation. For example, the study of function-valued traits in a phylogenetic comparative perspective may provide a more nuanced context for the evolutionary diversification of photosynthetic variation, some of which may be overlooked when studying univariate summary metrics. In this study, we measured light response curves on multiple replicates of 28 diploid wild sunflower (Helianthus) species. We determined physiological parameters such as maximum photosynthetic rate, quantum yield, and light compensation point, and we performed ancestral state reconstruction of photosynthetic variation in wild sunflowers using both individual traits as well as a function-valued trait approach. We compare the relative strengths and weaknesses of each approach, discuss potential challenges in studying function-valued traits, and provide recommendations for phylogenetic comparative studies involving function-valued trait variation.

1 - University Of Central Florida, Biology, 4110 Libra Drive, Orlando, FL, 32817, United States
2 - University Of Central Florida, Department Of Biology, 4110 Libra Dr, Orlando, FL, 32816, United States
3 - University Of Central Florida, 4000 Central Florida Blvd, BLDG20, BL301, Orlando, FL, 32816, United States

Phylogenetic comparative methods

Presentation Type: Poster
Number: PCW007
Abstract ID:634
Candidate for Awards:Phytochemical Best Poster Award

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